Antenna device

This application claims priority to Taiwan Application Serial Number 107104374, filed Feb. 7, 2018, which are herein incorporated by reference.

Technology Field

The present disclosure relates to an antenna device. More particularly, the present disclosure relates to an antenna device relating to beam switching.

With the rapid development of wireless communication technology, the transmission stability of wireless signals and the energy intensity of wireless transmission are becoming more and more important in communication quality. Nowadays, a common method for solving poor communication quality is to use an antenna device with a directional antenna to align the orientation of the antenna with the direction of the user.

In recent years, the method of using a directional antenna to generate a radiation pattern is generally to couple a switch to a reflection unit, for controlling the reflection unit to adjust the radiation pattern generated by the antenna unit. However, the method of coupling the switch to the reflection unit causes the poor directivity and poor front-to-back ratio of the radiation pattern, so that the radiation pattern still receives energy in the outward direction, and interferes with other antenna devices.

Therefore, designing an antenna device that is better in directivity and front-to-back ratio without causing an impedance problem when switching between the omnidirectional mode and the directional mode becomes an important goal today.

To solve the problems discussed above, the present disclosure provides an antenna device comprising antenna units, transmission lines and switching circuits. The antenna units are used for operating in a directional mode or an omni-directional mode. The transmission lines are coupled to the antenna units. The switching circuits are coupled to the respective transmission lines and are used for selectively connecting the transmission lines according to control signals to transmit a RF signal to the antenna units corresponding to the connected transmission lines. The switching circuits disconnects at least one of the transmission lines according to the control signals when the antenna units are operated in the directional mode; the switching circuits connects the transmission lines according to the control signals when the antenna units are operated in the omni-directional mode.

One embodiment of the present disclosure provides an antenna device comprising antenna units, transmission lines and impedance units. The antenna units are operated in a directional mode or an omni-directional mode. The switches are coupled to the antenna units and are used for selectively connecting the antenna units according to control signals from a control circuit to transmit a RF signal from the signal feed point to the connected antenna units. Impedance units are coupled to the respective antenna units and are coupled to the switches in series or in parallel to block the mutual interference among the control signals and the RF signal. The switches disconnect at least one of the antenna units according to the control signals when the antenna units are operated in the directional mode; the switches connect the antenna units according to the control signals when the antenna units are operated in the omni-directional mode.

In sum, the present disclosure provides switches disposed on the transmission lines and the antenna units to achieve better front-to-back ratio by changing radiation patterns via switches.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.

It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.

The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:

FIG. 1 is a perspective view showing an antenna device according to embodiments of the present disclosure;

FIG. 2A is a top view showing an antenna device according to embodiments of the present disclosure;

FIG. 2B is a bottom view showing an antenna device according to embodiments of the present disclosure;

FIG. 2C is a circuit diagram of antenna devices of FIGS. 2A and 2B according to embodiments of the present disclosure;

FIG. 3A is a top view showing an antenna device according to embodiments of the present disclosure;

FIG. 3B is a bottom view showing an antenna device according to embodiments of the present disclosure;

FIG. 3C is a circuit diagram of antenna devices of FIGS. 3A and 3B according to embodiments of the present disclosure;

FIG. 4A is a top view showing an antenna device according to embodiments of the present disclosure;

FIG. 4B is a bottom view showing an antenna device according to embodiments of the present disclosure;

FIG. 4C is a circuit diagram of antenna devices of FIGS. 4A and 4B according to embodiments of the present disclosure;

FIG. 5A is a top view showing an antenna device according to embodiments of the present disclosure;

FIG. 5B is a bottom view showing an antenna device according to embodiments of the present disclosure; and

FIG. 5C is a circuit diagram of antenna devices of FIGS. 5A and 5B according to embodiments of the present disclosure.

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

The terms “coupled” or “connected” as used in the various embodiments below may mean that two or more elements are “directly” in physical or electrical contact, or are “indirectly” in physical or electrical contact with each other. It can also mean that two or more elements interact with each other.

In some embodiments, an antenna device 100 disclosed in the present disclosure is an antenna device 100 with adjustable radiation pattern, which can adjust the radiation pattern generated by the antenna device 100 according to the location of the user, thereby achieving better transmission efficiency.

FIG. 1 is a perspective view showing an antenna device 100 according to embodiments of the present disclosure. As shown in FIG. 1 , in some embodiments, the antenna device 100 is disposed above the ground plane 160 and is connected to the ground plane 160 by four pillars 170 . In some embodiments, the antenna device 100 is a horizontally polarized antenna device for generating radiation in the horizontal direction.

In some embodiments, the antenna device 100 can be integrated in an electronic device with wireless communication functions, like an Access Point (AP), a Personal Computer (PC) or a Laptop. Not limited to the above, any electronic device capable of supporting multi-input multi-output (MIMO) communication technology and having communication functions is within the scope of the present disclosure. In practical applications, the antenna device 100 adjusts its radiation pattern according to the control signal to achieve an omni-directional radiation pattern or a directional radiation pattern.

In some embodiments, references are made to FIGS. 2A, 2B and 2C . FIG. 2A is a top view showing an antenna device 200 according to embodiments of the present disclosure. FIG. 2B is a bottom view showing an antenna device 200 according to embodiments of the present disclosure. FIG. 2C is a circuit diagram of antenna devices 200 of FIGS. 2A and 2B according to embodiments of the present disclosure. In some embodiments, the antenna device 200 is configured for operating in low frequency. For example, the low frequency includes 2.4 GHz. Not limited to the above, any frequency in which the antenna device 200 is configured for operating is within the scope of the present disclosure.

In some embodiments, as shown in FIGS. 2A, 2B and 2C , the antenna device 200 comprises antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , reflection units 251 , 252 , 253 and 254 , transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , switching circuits 261 , 262 , 263 and 264 , inductors L 13 and L 14 , control circuit 241 , signal feed point 280 , and substrate 270 . The transmission line 201 is coupled to the antenna unit 210 a . The transmission line 202 is coupled to the antenna unit 210 b . The transmission line 211 is coupled to the antenna unit 220 a . The transmission line 212 is coupled to the antenna unit 220 b . The transmission line 221 is coupled to the antenna unit 230 a . The transmission line 222 is coupled to the antenna unit 230 b . The transmission line 231 is coupled to the antenna unit 240 a . The transmission line 232 is coupled to the antenna unit 240 b . The switching circuits 261 and 262 are coupled to the transmission lines 221 , 222 , 231 and 232 . The switching circuits 263 and 264 are coupled to the transmission lines 201 , 202 , 211 and 212 . The switching circuits 261 , 262 , 263 and 264 are coupled to the inductors L 13 and L 14 , respectively. In some embodiments, the antenna units 210 a , 220 a , 230 a and 240 a and the transmission lines 201 , 211 , 221 and 231 are disposed on the first surface 271 of the substrate 270 . The antenna units 210 b , 220 b , 230 b and 240 b , the reflection units 251 , 252 , 253 and 254 and the transmission lines 202 , 212 , 222 and 232 are disposed on the second surface 272 of the substrate 270 opposite to the first surface 271 . The antenna units 210 a and 210 b are disposed between the reflection units 251 and 252 . The antenna units 220 a and 220 b are disposed between the reflection units 252 and 253 . The antenna units 230 a and 230 b are disposed between the reflection units 253 and 254 . The antenna units 240 a and 240 b are disposed between the reflection units 254 and 251 .

In some embodiments, the signal feed point 280 is disposed at the cross points of the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 . Not limited to the above, the signal feed point 280 can be disposed at any location on (or any location outside) the substrate 270 that can be connected to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b.

In some embodiments, the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b are operated as transmission antennas individually receiving RF signals from the signal feed point 280 , and thereby the antenna device 200 generates a radiation pattern accordingly. The direction of the radiation pattern extends outward from the signal feed point 280 . In some embodiments, the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b are operated as reception antennas individually receiving a wireless signal from users, and thereby a wireless signal channel is established accordingly. In some embodiments, the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b can be implemented by a Planar Inverted F Antenna (PIFA), a dipole antenna or a loop antenna. Not limited to the above, any circuit element that is suitable for implementing the horizontally polarized antenna unit is within the scope of the present disclosure.

In some embodiments, the antenna device 200 has four antenna unit sets 210 , 220 , 230 and 240 . The antenna unit set 210 includes the antenna units 210 a and 210 b . The antenna unit set 220 includes the antenna units 220 a and 220 b . The antenna unit set 230 includes the antenna units 230 a and 230 b . The antenna unit set 240 includes the antenna units 240 a and 240 b . In these embodiments, the antenna device 200 has four antenna unit sets 210 , 220 , 230 and 240 . Not limited to the above, any antenna device 200 having more than two antenna unit sets is within the scope of the present disclosure.

In some embodiments, each of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b forms an L-shape with a corresponding one of the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 . For example, the antenna unit 210 a forms an L-shape with the transmission line 201 . The antenna unit 210 b forms an L-shape with the transmission line 202 . The antenna unit 220 a forms an L-shape with the transmission line 211 . The antenna unit 220 b forms an L-shape with the transmission line 212 . The antenna unit 230 a forms an L-shape with the transmission line 221 . The antenna unit 230 b forms an L-shape with the transmission line 222 . The antenna unit 240 a forms an L-shape with the transmission line 231 . The antenna unit 240 b forms an L-shape with the transmission line 232 .

In some embodiments, the reflection units 251 , 252 , 253 and 254 are used for adjusting the radiation patterns of the antenna unit sets 210 , 220 , 230 and 240 . For example, the reflection units 251 and 252 are used for adjusting the corresponding radiation patterns of the antenna units 210 a and 210 b . The reflection units 252 and 253 are used for adjusting the corresponding radiation pattern of the antenna units 220 a and 220 b . The reflection units 253 and 254 are used for adjusting the corresponding radiation patterns of the antenna units 230 a and 230 b ; and the reflection units 254 and 251 are used for adjusting the corresponding radiation patterns of the antenna units 240 a and 240 b , and thus each of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b may have a directional radiation pattern. In some other embodiments, the shapes of the reflection units 251 , 252 , 253 and 254 can be adjusted according to the X, Y, Z axes.

In some embodiments, the reflection units 251 , 252 , 253 and 254 are coupled to the substrate 270 and are disposed at the two sides of each of the antenna unit sets 210 , 220 , 230 and 240 . In some embodiments, the reflection units 251 , 252 , 253 and 254 can be implemented by thin metal strips. Not limited to the above, any reflection unit that can be used to implement the radiation pattern adjustment is within the scope of the present disclosure.

In some embodiments, the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 are used to transmit the RF signals from the signal feed point 280 to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . In some embodiments, the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 can be implemented by metal wires. Not limited to the above, any wire that can be used to transmit RF signals is within the scope of the present disclosure.

In some embodiments, the control circuit 241 is used for generating control signals CT 11 , CT 12 , CT 13 and CT 14 . In some embodiments, the control circuit 241 can be implemented by a server, a circuit, a central processor unit (CPU) or a microcontroller unit (MCU) having functions of computing, reading data, receiving signals or messages, transmitting signals or messages or the likes, or other electronic chips having equivalent functions.

In some embodiments, the switching circuits 261 , 262 , 263 and 264 are used for selectively connecting at least one of the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 according to the control signals CT 11 , CT 12 , CT 13 and CT 14 from the control circuit 241 , to transmit RF signals to the corresponding antenna units of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . In some embodiments, the practical configurations of the switching circuits 261 , 262 , 263 and 264 are shown in FIG. 2C .

In some embodiments, as shown in FIG. 2C , the switching circuit 261 includes a PIN diode D 4 , a PIN diode D 8 and an impedance unit 281 . The switching circuit 262 includes a PIN diode D 7 , a PIN diode D 3 and an impedance unit 282 . The switching circuit 263 includes a PIN diode D 1 , a PIN diode D 5 and an impedance unit 283 ; and the switching circuit 264 includes a PIN diode D 6 , a PIN diode D 2 and an impedance unit 284 .

In some embodiments, the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the switching circuits 261 , 262 , 263 and 264 are disposed on the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , respectively, for blocking or conducting the RF signal from the signal feed point 280 to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . For example, when it is intended to disconnect the antenna units 240 a and 240 b , the PIN diode D 4 and the PIN diode D 8 are used to block the RF signal transmitting to the antenna units 240 a and 240 b via the transmission lines 231 and 232 . When it is intended to disconnect the antenna units 230 a and 230 b , the PIN diode D 7 and the PIN diode D 3 are used to block the RF signal transmitting to the antenna units 230 a and 230 b via the transmission lines 221 and 222 . When it is intended to disconnect the antenna units 210 a and 210 b , the PIN diode D 1 and the PIN diode D 5 are used to block the RF signal transmitting to the antenna units 210 a and 210 b via the transmission lines 201 and 202 . When it is intended to disconnect the antenna units 220 a and 220 b , the PIN diode D 6 and the PIN diode D 2 are used to block the RF signal transmitting to the antenna units 220 a and 220 b via the transmission lines 211 and 212 .

In some embodiments, the impedance unit 281 includes the inductors L 1 , L 2 , L 8 and L 12 and the capacitor C 4 . The impedance unit 282 includes the inductors L 11 and L 3 and the capacitor C 3 . The impedance unit 283 includes the inductors L 5 , L 6 , L 7 and L 9 and the capacitor C 1 . The impedance unit 284 includes the inductors L 10 and L 4 and the capacitor C 2 .

In some embodiments, the inductors L 1 -L 12 in the impedance units 281 , 282 , 283 and 284 and the inductors L 13 and L 14 work as RF chokes. In particular, the inductors L 1 -L 14 are used to block the mutual interference among the RF signals transmitting on the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 . In some embodiments, the capacitors C 1 -C 4 in the impedance units 281 , 282 , 283 and 284 work as DC blocks. In particular, the capacitors C 1 -C 4 are used to block the mutual interference among the control signals CT 11 , CT 12 , CT 13 and CT 14 .

In some embodiments, as shown in FIG. 2A , the PIN diodes D 1 -D 4 , the inductors L 1 -L 8 and L 14 and the capacitors C 1 -C 4 are disposed on the first surface 271 of the substrate 270 . In some embodiments, as shown in FIG. 2B , the PIN diodes D 5 -D 8 , the inductors L 9 -L 13 are disposed on the second surface 272 of the substrate 270 .

In some embodiments, as shown in FIG. 2C , the first end of the inductor L 2 is used to receive the control signal CT 11 . The second end of the inductor L 2 is coupled to the first end of the capacitor C 3 , the transmission line 221 and the first end of the inductor L 1 . The second end of the inductor L 1 is coupled to the first end of the inductor L 8 and the first end of the inductor L 12 . The second end of the inductor L 8 is coupled to the second end of the capacitor C 4 and the first end of the PIN diode D 4 . The first end of the capacitor C 4 is coupled to the transmission line 231 . The second end of the capacitor C 4 is coupled to the first end of the PIN diode D 4 . The second end of the PIN diode D 4 is coupled to the first end of the inductor L 14 . The second end of the inductor L 12 is coupled to the transmission line 232 and the first end of the PIN diode D 8 . The second end of the PIN diode D 8 is coupled to the first end of the inductor L 13 . The first end of the inductor L 11 is used to receive the control signal CT 12 . The second end of the inductor L 11 is coupled to the transmission line 222 and the first end of the PIN diode D 7 . The second end of the PIN diode D 7 is coupled to the first end of the inductor L 13 . The first end of the inductor L 3 is used to receive the control signal CT 12 . The second end of the inductor L 3 is coupled to the first end of the PIN diode D 3 and the second end of the capacitor C 3 . The second end of the PIN diode D 3 is coupled to the first end of the inductor L 14 . The first end of the inductor L 5 is used to receive the control signal CT 14 . The second end of the inductor L 5 is coupled to the first end of the capacitor C 2 , the transmission line 211 and the first end of the inductor L 6 . The second end of the inductor L 6 is coupled to the first end of the inductor L 7 and the first end of the inductor L 9 . The second end of the inductor L 7 is coupled to the second end of the capacitor C 1 and the first end of the PIN diode D 1 . The first end of the capacitor C 1 is coupled to the transmission line 201 . The second end of the capacitor C 1 is coupled to the first end of the PIN diode D 1 . The second end of the PIN diode D 1 is coupled to the first end of the inductor L 14 . The second end of the inductor L 9 is coupled to the transmission line 202 and the first end of the PIN diode D 5 . The second end of the PIN diode D 5 is coupled to the first end of the inductor L 13 . The first end of the inductor L 10 is used to receive the control signal CT 13 . The second end of the inductor L 10 is coupled to the transmission line 212 and the first end of the PIN diode D 6 . The second end of the PIN diode D 6 is coupled to the first end of the inductor L 13 . The first end of the inductor L 4 is used to receive the control signal CT 13 . The second end of the inductor L 4 is coupled to the first end of the PIN diode D 2 and the second end of the capacitor C 2 . The second end of the PIN diode D 2 is coupled to the first end of the inductor L 14 . The second end of the inductor L 13 and the second end of the inductor L 14 are connected to ground.

In some embodiments, the antenna device 200 has two operation modes, an omni-directional mode and a directional mode. In practical applications, the omnidirectional mode or the directivity mode is switched by controlling at least one of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the antenna device 200 to be turned on. For example, when it is intended to operate in the antenna device 200 in the omni-directional mode, all of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 are turned on to produce an omni-directional radiation pattern. When it is intended to operate the antenna device 200 in the directional mode, the PIN diodes D 1 , D 4 , D 5 and D 8 are turned on and the PIN diodes D 2 , D 3 , D 6 and D 7 are turned off to produce a radiation pattern as the one propagating toward the upper right of FIG. 2A ; that is, the 45 degree direction as shown in FIG. 1 . The PIN diodes D 3 , D 4 , D 7 and D 8 are turned on and the PIN diodes D 1 , D 2 , D 5 and D 6 are turned off to produce a radiation pattern as the one propagating toward the lower right of FIG. 2A ; that is, the 135 degree direction as shown in FIG. 1 . The PIN diodes D 2 , D 3 , D 6 and D 7 are turned on and the PIN diodes D 1 , D 4 , D 5 and D 8 are turned off to produce a radiation pattern as the one propagating toward the lower left of FIG. 2A ; that is, the 225 degree direction as shown in FIG. 1 . The PIN diodes D 1 , D 2 , D 5 and D 6 are turned on and the PIN diodes D 3 , D 4 , D 7 and D 8 are turned off to produce a radiation pattern as the one propagating toward the upper left of FIG. 2A ; that is, the 315 degree direction as shown in FIG. 1 .

From the embodiments mentioned above, it can be seen that when the radiation patterns of the antenna device 200 are switched, the PIN diodes on at least two adjacent transmission lines of transmission lines 201 , 211 , 221 and 231 are turned on. It is because that the return loss would be too large if only the PIN diodes on one of the transmission lines 201 , 211 , 221 and 231 are turned on.

In some embodiments, references are made to FIGS. 3A, 3B and 3C . FIG. 3A is a top view showing an antenna device 300 according to embodiments of the present disclosure. FIG. 3B is a bottom view showing an antenna device 300 according to embodiments of the present disclosure. FIG. 3C is a circuit diagram of antenna devices 300 of FIGS. 3A and 3B according to embodiments of the present disclosure. In some embodiments, the antenna device 300 is configured to operate in high frequency. For example, the high frequency includes 5 GHz. Not limited to the above, any frequency at which the antenna device 300 is configured to operate is within the scope of the present disclosure.

In some embodiments, as shown in FIGS. 3A, 3B and 3C , in addition to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , the reflection units 251 , 252 , 253 and 254 , the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , the inductors L 13 and L 14 , the control circuit 241 and the substrate 270 , the antenna device 300 further includes switching circuits 361 , 362 , 363 and 364 . The element characteristics and the operations of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , the reflection units 251 , 252 , 253 and 254 , the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , the inductors L 13 and L 14 , the control circuit 241 and the substrate 270 are the same as the elements with identical reference numerals in the antenna device 200 .

In some embodiments, as shown in FIG. 3C , the switching circuit 361 includes the PIN diode D 4 , the PIN diode D 8 , the impedance unit 381 , the inductor L 15 and the inductor L 20 . In some embodiments, the inductor L 15 and the inductor L 20 are connected in parallel with the PIN diode D 4 and the PIN diode D 8 , respectively, to form a band-stop filter blocking the RF signal. In some embodiments, as shown in FIG. 3C , the switching circuit 362 includes the PIN diode D 7 , the PIN diode D 3 , the impedance unit 382 , the inductor L 21 and the inductor L 18 . In some embodiments, the inductor L 21 and the inductor L 18 are connected in parallel with the PIN diode D 7 and the PIN diode D 3 , respectively, to form a band-stop filter blocking the RF signal. In some embodiments, as shown in FIG. 3C , the switching circuit 363 includes the PIN diode D 1 , the PIN diode D 5 , the impedance unit 383 , the inductor L 16 and the inductor L 19 . In some embodiments, the inductor L 16 and the inductor L 19 are connected in parallel with the PIN diode D 1 and the PIN diode D 5 , respectively, to form a band-stop blocking the RF signal. In some embodiments, as shown in FIG. 3C , the switching circuit 364 includes the PIN diode D 6 , the PIN diode D 2 , the impedance unit 384 , the inductor L 22 and the inductor L 17 . In some embodiments, the inductor L 22 and the inductor L 17 are connected in parallel with the PIN diode D 6 and the PIN diode D 2 , respectively, to form a band-stop filter blocking the RF signal.

In some embodiments, the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the switching circuits 361 , 362 , 363 and 364 are disposed on the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , respectively, for blocking or conducting the RF signal from the signal feed point 280 to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . For example, when it is intended to disconnect the antenna units 240 a and 240 b , the PIN diode D 4 and the PIN diode D 8 are used to block the RF signal transmitting to the antenna units 240 a and 240 b via the transmission lines 231 and 232 . When it is intended to disconnect the antenna units 230 a and 230 b , the PIN diode D 7 and the PIN diode D 3 are used to block the RF signal transmitting to the antenna units 230 a and 230 b via the transmission lines 221 and 222 . When it is intended to disconnect the antenna units 210 a and 210 b , the PIN diode D 1 and the PIN diode D 5 are used to block the RF signal transmitting to the antenna units 210 a and 210 b via the transmission lines 201 and 202 . When it is intended to disconnect the antenna units 220 a and 220 b , the PIN diode D 6 and the PIN diode D 2 are used to block the RF signal transmitting to the antenna units 220 a and 220 b via the transmission lines 211 and 212 .

In some embodiments, as shown in FIG. 3C , the impedance unit 381 includes the inductors L 2 , L 1 , L 8 and L 12 and the capacitors C 4 , C 9 and C 8 . The impedance unit 382 includes the inductors L 11 and L 3 and the capacitors C 3 , C 7 and C 12 . The impedance unit 383 includes the inductors L 5 , L 6 , L 7 and L 9 and the capacitors C 1 , C 10 and C 5 . The impedance unit 384 includes the inductors L 10 and L 4 and the capacitors C 2 , C 6 and C 11 .

In some embodiments, the inductors L 1 -L 12 in the impedance units 381 , 382 , 383 and 384 and the inductors L 13 and L 14 work as RF chokes. In particular, the inductors L 1 -L 14 are used to block the mutual interference among the RF signals transmitting on the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 . In some embodiments, the capacitors C 1 -C 12 in the impedance units 381 , 382 , 383 and 384 work as DC blocks. In particular, the capacitors C 1 -C 12 are used to block mutual interference among the control signals CT 21 , CT 22 , CT 23 and CT 24 from the control circuit 241 .

In some embodiments, as shown in FIG. 3A , the PIN diodes D 1 -D 4 , the inductors L 1 -L 8 and L 1 -L 17 and the capacitors C 1 -C 4 and C 9 -C 12 are disposed on the first surface 271 of the substrate 270 . In some embodiments, as shown in FIG. 3B , the PIN diodes D 5 -D 8 , the inductors L 9 -L 13 and L 19 -L 22 and the capacitors C 5 -C 8 are disposed on the second surface 272 of the substrate 270 . In some embodiments, as shown in FIG. 3C , the first end of the inductor L 2 is used to receive the control signal CT 21 . The second end of the inductor L 2 is coupled to the first end of the capacitor C 3 , the transmission line 221 and the first end of the inductor L 1 . The second end of the inductor L 1 is coupled to the first end of the inductor L 8 and the first end of the inductor L 12 . The second end of the inductor L 8 is coupled to the second end of the capacitor C 4 , the first end of the PIN diode D 4 and the first end of the capacitor C 9 . The first end of the capacitor C 4 is coupled to the transmission line 231 . The second end of the capacitor C 4 is coupled to the first end of the capacitor C 9 and the first end of the PIN diode D 4 . The second end of the capacitor C 9 is coupled to the first end of the inductor L 15 . The second end of the inductor L 15 is coupled to the second end of the PIN diode D 4 and the first end of the inductor L 14 . The second end of the inductor L 12 is coupled to the transmission line 232 , the first end of the PIN diode D 8 and the first end of the capacitor C 8 . The second end of the capacitor C 8 is coupled to the first end of the inductor L 20 . The second end of the inductor L 20 is coupled to the second end of the PIN diode D 8 and the first end of the inductor L 13 . The first end of the inductor L 11 is used to receive the control signal CT 22 . The second end of the inductor L 11 is coupled to the transmission line 222 , the first end of the PIN diode D 7 and the first end of the capacitor C 7 . The second end of the capacitor C 7 is coupled to the first end of the inductor L 21 . The second end of the inductor L 21 is coupled to the second end of the PIN diode D 7 and the first end of the inductor L 13 . The first end of the inductor L 3 is used to receive the control signal CT 22 . The second end of the inductor L 3 is coupled to the first end of the PIN diode D 3 , the second end of the capacitor C 3 and the first end of the capacitor C 12 . The second end of the capacitor C 12 is coupled to the first end of the inductor L 18 . The second end of the inductor L 18 is coupled to the second end of the PIN diode D 3 and the first end of the inductor L 14 . The first end of the inductor L 5 is used to receive the control signal CT 24 . The second end of the inductor L 5 is coupled to the first end of the capacitor C 2 , the transmission line 211 and the first end of the inductor L 6 . The second end of the inductor L 6 is coupled to the first end of the inductor L 7 and the first end of the inductor L 9 . The second end of the inductor L 7 is coupled to the second end of the capacitor C 1 , the first end of the PIN diode D 1 and the first end of the capacitor C 10 . The first end of the capacitor C 1 is coupled to the transmission line 201 . The second end of the capacitor C 1 is coupled to the first end of the PIN diode D 1 and the first end of the capacitor C 10 . The second end of the capacitor C 10 is coupled to the first end of the inductor L 16 . The second end of the inductor L 16 is coupled to the second end of the PIN diode D 1 and the first end of the inductor L 14 . The second end of the inductor L 9 is coupled to the transmission line 202 , the first end of the PIN diode D 5 and the first end of the capacitor C 5 . The second end of the capacitor C 5 is coupled to the first end of the inductor L 19 . The second end of the inductor L 19 is coupled to the second end of the PIN diode D 5 and the first end of the inductor L 13 . The first end of the inductor L 10 is used to receive the control signal CT 23 . The second end of the inductor L 10 is coupled to the transmission line 212 , the first end of the PIN diode D 6 and the first end of the capacitor C 6 . The second end of the capacitor C 6 is coupled to the first end of the inductor L 22 . The second end of the inductor L 22 is coupled to the second end of the PIN diode D 6 and the first end of the inductor L 13 . The first end of the inductor L 4 is used to receive the control signal CT 23 . The second end of the inductor L 4 is coupled to the first end of the PIN diode D 2 , the second end of the capacitor C 2 and the first end of the capacitor C 11 . The second end of the capacitor C 11 is coupled to the first end of the inductor L 17 . The second end of the inductor L 17 is coupled to the second end of the PIN diode D 2 and the first end of the inductor L 14 . The second end of the inductor L 13 and the second end of the inductor L 14 are connected to ground.

In some embodiments, the antenna device 300 has two operation modes, an omni-directional mode and a directional mode. In practical applications, the omnidirectional mode or the directivity mode is switched by turning on at least one of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the antenna device 300 . For example, when it is intended to operate the antenna device 300 in the omni-directional mode, all of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 are turned on to produce the omni-directional radiation pattern. When it is intended to operate the antenna device 300 in the directional mode, the PIN diodes D 1 , D 4 , D 5 and D 8 are turned on and the PIN diodes D 2 , D 3 , D 6 and D 7 are turned off to produce a radiation pattern as the one propagating toward the upper right of FIG. 3A ; that is, the 45 degree direction as shown in FIG. 1 . The PIN diodes D 3 , D 4 , D 7 and D 8 are turned on and the PIN diodes D 1 , D 2 , D 5 and D 6 are turned off to produce a radiation pattern as the one propagating toward the lower right of FIG. 3A ; that is, the 135 degree direction as shown in FIG. 1 . The PIN diodes D 2 , D 3 , D 6 and D 7 are turned on and the PIN diodes D 1 , D 4 , D 5 and D 8 are turned off to produce a radiation pattern as the one propagating toward the lower left of FIG. 3A ; that is, the 225 degree direction as shown in FIG. 1 . The PIN diodes D 1 , D 2 , D 5 and D 6 are turned on and the PIN diodes D 3 , D 4 , D 7 and D 8 are turned off to produce a radiation pattern as the one propagating toward the upper left of FIG. 3A ; that is, the 315 degree direction as shown in FIG. 1 .

In some embodiments, references are made to FIGS. 4A, 4B and 4C . FIG. 4A is a top view showing an antenna device 400 according to embodiments of the present disclosure. FIG. 4B is a bottom view showing an antenna device 400 according to embodiments of the present disclosure. FIG. 4C is a circuit diagram of antenna devices 400 of FIGS. 4A and 4B according to embodiments of the present disclosure. In some embodiments, the antenna device 400 is configured to operate in high frequency. For example, the high frequency includes 5 GHz. Not limited to the above, any frequency in which the antenna device 400 could be configured to operate is within the scope of the present disclosure.

In some embodiments, as shown in FIGS. 4A and 4B , in addition to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , the reflection units 251 , 252 , 253 and 254 , the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , the control circuit (not shown) and the substrate 270 , the antenna device 400 further includes switching circuits 461 , 462 , 463 and 464 . The element characteristics and the operations of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , the reflection units 251 , 252 , 253 and 254 , the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , the control circuit (not shown) and the substrate 270 are the same as the elements with identical reference numerals in the antenna device 200 .

In some embodiments, as shown in FIG. 4C , the switching circuit 461 includes the PIN diode D 1 , the PIN diode D 5 , the impedance unit 481 , the inductor L 16 and the inductor L 19 . In some embodiments, the inductor L 16 and the inductor L 19 are connected in parallel with the PIN diode D 4 and the PIN diode D 5 , respectively, to form a band-stop filter blocking the RF signal. In some embodiments, as shown in FIG. 4C , the switching circuit 462 includes the PIN diode D 2 , the PIN diode D 6 , the impedance unit 482 , the inductor L 17 and the inductor L 22 . In some embodiments, the inductor L 17 and the inductor L 22 are connected in parallel with the PIN diode D 2 and the PIN diode D 6 , respectively, to form a band-stop filter blocking the RF signals. In some embodiments, as shown in FIG. 4C , the switching circuit 463 includes the PIN diode D 3 , the PIN diode D 7 , the impedance unit 483 , the inductor L 18 and the inductor L 21 . In some embodiments, the inductor L 18 and the inductor L 21 are connected in parallel with the PIN diode D 3 and the PIN diode D 7 , respectively, to form a band-stop filter blocking the RF signals. In some embodiments, as shown in FIG. 4C , the switching circuit 464 includes the PIN diode D 4 , the PIN diode D 8 , the impedance unit 484 , the inductor L 15 and the inductor L 20 . In some embodiments, the inductor L 15 and the inductor L 20 are connected in parallel with the PIN diode D 4 and the PIN diode D 8 , respectively, to form a band-stop filter blocking the RF signal.

In some embodiments, the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the switching circuits 461 , 462 , 463 and 464 are disposed on the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , respectively, for blocking or conducting the RF signal from the signal feed point 280 to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . For example, when it is intended to disconnect the antenna units 240 a and 240 b , the PIN diode D 4 and the PIN diode D 8 are used to block the RF signal transmitting to the antenna units 240 a and 240 b . When it is intended to disconnect the antenna units 230 a and 230 b , the PIN diode D 7 and the PIN diode D 3 are used to block the RF signal transmitting to the antenna units 230 a and 230 b . When it is intended to disconnect the antenna units 210 a and 210 b , the PIN diode D 1 and the PIN diode D 5 are used to block the RF signal transmitting to the antenna units 210 a and 210 b . When it is intended to disconnect the antenna units 220 a and 220 b , the PIN diode D 6 and the PIN diode D 2 are used to block the RF signal transmitting to the antenna units 220 a and 220 b.

In some embodiments, as shown in FIG. 4C , the impedance unit 481 includes the inductor L 9 , the capacitor C 1 , the inductor L 3 , the capacitor C 5 and the inductor L 4 . The impedance unit 482 includes the inductor L 12 , the capacitor C 2 , the inductor L 5 , the capacitor C 6 and the inductor L 6 . The impedance unit 483 includes the inductor L 11 , the capacitor C 3 , the inductor L 7 , the capacitor C 7 and the inductor L 8 . The impedance unit 484 includes the inductor L 10 , the capacitor C 4 , the inductor L 1 , the capacitor C 8 and the inductor L 2 .

In some embodiments, the inductors L 1 -L 12 in the impedance units 481 , 482 , 483 and 484 work as RF chokes. In particular, the inductors L 1 -L 12 are used to block the mutual interference among the RF signals transmitting on the transmission lines 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . In some embodiments, the capacitors C 1 -C 8 in the impedance units 481 , 482 , 483 and 484 work as DC blocks. In particular, the capacitors C 1 -C 8 are used to block the mutual interference among the control signals CT 31 , CT 32 , CT 33 and CT 34 from the control circuit (not shown).

In some embodiments, as shown in FIG. 4A , the PIN diodes D 1 -D 4 , the inductors L 1 -L 8 and L 15 -L 18 and the capacitors C 1 -C 4 are disposed on the first surface 271 of the substrate 270 . In some embodiments, as shown in FIG. 4B , the PIN diodes D 5 -D 8 , the inductors L 9 -L 13 and L 19 -L 22 and the capacitors C 5 -C 8 are disposed on the second surface 272 of the substrate 270 .

In some embodiments, as shown in FIG. 4C , the first end of the inductor L 9 is used to receive the control signal CT 31 . The second end of the inductor L 9 is coupled to the first end of the PIN diode D 1 and the first end of the inductor L 16 . The second end of the inductor L 16 is coupled to the first end of the capacitor C 1 . The second end of the PIN diode D 1 is coupled to the second end of the capacitor C 1 and the first end of the inductor L 3 . The second end of the inductor L 3 is coupled to the first end of the PIN diode D 5 and the first end of the capacitor C 5 . The second end of the capacitor C 5 is coupled to the first end of the inductor L 19 . The second end of the inductor L 19 is coupled to the second end of the PIN diode D 5 and the first end of the inductor L 4 . The second end of the inductor L 4 is connected to ground. The first end of the inductor L 12 is used to receive the control signal CT 32 . The second end of the inductor L 12 is coupled to the first end of the PIN diode D 2 and the first end of the inductor L 17 . The second end of the inductor L 17 is coupled to the first end of the capacitor C 2 . The second end of the PIN diode D 2 is coupled to the second end of the capacitor C 2 and the first end of the inductor L 5 . The second end of the inductor L 5 is coupled to the first end of the PIN diode D 6 and the first end of the capacitor C 6 . The second end of the capacitor C 6 is coupled to the first end of the inductor L 22 . The second end of the inductor L 22 is coupled to the second end of the PIN diode D 6 and the first end of the inductor L 6 . The second end of the inductor L 6 is connected to ground. The first end of the inductor L 11 is used to receive the control signal CT 33 . The second end of the inductor L 11 is coupled to the first end of the PIN diode D 3 and the first end of the inductor L 18 . The second end of the inductor L 18 is coupled to the first end of the capacitor C 3 . The second end of the PIN diode D 3 is coupled to the second end of the capacitor C 3 and the first end of the inductor L 7 . The second end of the inductor L 7 is coupled to the first end of the PIN diode D 7 and the first end of the capacitor C 7 . The second end of the capacitor C 7 is coupled to the first end of the inductor L 21 . The second end of the inductor L 21 is coupled to the second end of the PIN diode D 7 and the first end of the inductor L 8 . The second end of the inductor L 8 is connected to ground. The first end of the inductor L 10 is used to receive the control signal CT 34 . The second end of the inductor L 10 is coupled to the first end of the PIN diode D 4 and the first end of the inductor L 15 . The second end of the inductor L 15 is coupled to the first end of the capacitor C 4 . The second end of the PIN diode D 4 is coupled to the second end of the capacitor C 4 and the first end of the inductor L 1 . The second end of the inductor L 1 is coupled to the first end of the PIN diode D 8 and the first end of the capacitor C 8 . The second end of the capacitor C 8 is coupled to the first end of the inductor L 20 . The second end of the inductor L 20 is coupled to the second end of the PIN diode D 8 and the first end of the inductor L 2 . The second end of the inductor L 2 is connected to ground.

In some embodiments, the antenna device 400 has two operation modes, an omni-directional mode and a directional mode. In practical applications, the omnidirectional mode or the directivity mode is switched by turning on at least one of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the antenna device 400 . For example, when it is intended to operate the antenna device 400 in the omni-directional mode, all of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 are turned on to produce an omni-directional radiation pattern. The PIN diodes D 1 , D 4 , D 5 and D 8 are turned on and the PIN diodes D 2 , D 3 , D 6 and D 7 are turned off to produce a radiation pattern as the one propagating toward the upper right of FIG. 4A ; that is, the 45 degree direction as shown in FIG. 1 . The PIN diodes D 3 , D 4 , D 7 and D 8 are turned on and the PIN diodes D 1 , D 2 , D 5 and D 6 are turned off to produce a radiation pattern as the one propagating toward the lower right of FIG. 4A ; that is, the 135 degree direction as shown in FIG. 1 . The PIN diodes D 2 , D 3 , D 6 and D 7 are turned on and the PIN diodes D 1 , D 4 , D 5 and D 8 are turned off to produce a radiation pattern as the one propagating toward the lower left of FIG. 4A ; that is, the 225 degree direction as shown in FIG. 1 . The PIN diodes D 1 , D 2 , D 5 and D 6 are turned on and the PIN diodes D 3 , D 4 , D 7 and D 8 are turned off to produce a radiation pattern as propagating toward the upper left of FIG. 4A ; that is, the 315 degree direction as shown in FIG. 1 .

In some embodiments, references are made to FIGS. 5A, 5B and 5C . FIG. 5A is a top view showing an antenna device 500 according to embodiments of the present disclosure. FIG. 5B is a bottom view showing an antenna device 500 according to embodiments of the present disclosure. FIG. 5C is a circuit diagram of antenna devices 500 of FIGS. 5A and 5B according to embodiments of the present disclosure. In some embodiments, the antenna device 500 is configured to operate in low frequency. For example, the low frequency includes 2.4 GHz. Not limited to the above, any frequency in which the antenna device 500 is configured to operate is within the scope of the present disclosure.

In some embodiments, as shown in FIGS. 5A and 5B , in addition to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , the reflection units 251 , 252 , 253 and 254 , the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , the control circuit (not shown) and the substrate 270 , the antenna device 500 further comprises switching circuits 561 , 562 , 563 and 564 . The element characteristics and the operations of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , the reflection units 251 , 252 , 253 and 254 , the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 , the control circuit (not shown) and the substrate 270 are the same as the elements with identical reference numerals in the antenna device 200 .

In some embodiments, as shown in FIG. 5C , the switching circuit 561 includes a PIN diode D 1 , a PIN diode D 5 and an impedance unit 581 . The switching circuit 562 includes a PIN diode D 2 , a PIN diode D 6 and an impedance unit 582 . The switching circuit 563 includes a PIN diode D 3 , a PIN diode D 7 and an impedance unit 583 . The switching circuit 564 includes a PIN diode D 4 , a PIN diode D 9 and an impedance unit 584 . In some embodiments, the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 are disposed on the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , respectively, for selectively disconnecting or connecting at least one of the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b according to control signals CT 41 , CT 42 , CT 43 and CT 44 , to transmit the RF signal from the signal feed point 280 to the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b . For example, when it is intended to disconnect the antenna units 240 a and 240 b , the PIN diode D 4 and the PIN diode D 8 are used to block the RF signal transmitting to the antenna units 240 a and 240 b . When it is intended to disconnect the antenna units 230 a and 230 b , the PIN diode D 7 and the PIN diode D 3 are used to block the RF signal transmitting to the antenna units 230 a and 230 b . When it is intended to disconnect the antenna units 210 a and 210 b , the PIN diode D 1 and the PIN diode D 5 are used to block the RF signal transmitting to the antenna units 210 a and 210 b . When it is intended to disconnect the antenna units 220 a and 220 b , the PIN diode D 6 and the PIN diode D 2 are used to block the RF signal transmitting to the antenna units 220 a and 220 b.

In some embodiments, as shown in FIG. 5C , the impedance unit 581 includes the inductor L 9 , the inductor L 3 and the inductor L 4 . The impedance unit 582 includes the inductor L 12 , the inductor L 5 and the inductor L 16 . The impedance unit 583 includes the inductor L 11 , the inductor L 7 and the inductor L 8 . The impedance unit 584 includes the inductor L 10 , the inductor L 1 and the inductor L 2 .

In some embodiments, the inductors L 1 -L 12 in the impedance units 581 , 582 , 583 and 584 work as RF chokes. In particular, the inductors L 1 -L 12 are used to block the mutual interference among the RF signals transmitting on the transmission lines 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b.

In some embodiments, a control circuit (not shown) is used to produce control signals CT 41 , CT 42 , CT 43 and CT 44 to control the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 to selectively connect the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b.

In some embodiments, as shown in FIG. 5A , the PIN diodes D 1 -D 4 , the inductors L 1 -L 8 are disposed on the first surface 271 of the substrate 270 . In some embodiments, as shown in FIG. 5B , the PIN diodes D 5 -D 8 , the inductors L 9 -L 12 are disposed on the second surface 272 of the substrate 270 .

In some embodiments, as shown in FIG. 5C , the first end of the inductor L 9 is used to receive the control signal CT 41 . The second end of the inductor L 9 is coupled to the first end of the PIN diode D 1 . The second end of the PIN diode D 1 is coupled to the first end of the inductor L 3 . The second end of the inductor L 3 is coupled to the first end of the PIN diode D 5 . The second end of the PIN diode D 5 is coupled to the first end of the inductor L 4 . The second end of the inductor L 4 is connected to ground. The first end of the inductor L 12 is used to receive the control signal CT 42 . The second end of the inductor L 12 is coupled to the first end of the PIN diode D 2 . The second end of the PIN diode D 2 is coupled to the first end of the inductor L 5 . The second end of the inductor L 5 is coupled to the first end of the PIN diode D 6 . The second end of the PIN diode D 6 is coupled to the first end of the inductor L 6 . The second end of the inductor L 6 is connected to ground. The first end of the inductor L 11 is used to receive the control signal CT 43 . The second end of the inductor L 11 is coupled to the first end of the PIN diode D 3 . The second end of the PIN diode D 3 is coupled to the first end of the inductor L 7 . The second end of the inductor L 7 is coupled to the first end of the PIN diode D 7 . The second end of the PIN diode D 7 is coupled to the first end of the inductor L 8 . The second end of the inductor L 8 is connected to ground. The first end of the inductor L 10 is used to receive the control signal CT 44 . The second end of the inductor L 10 is coupled to the first end of the PIN diode D 4 . The second end of the PIN diode D 4 is coupled to the first end of the inductor L 1 . The second end of the inductor L 1 is coupled to the first end of the PIN diode D 8 . The second end of the PIN diode D 8 is coupled to the first end of the inductor L 2 . The second end of the inductor L 2 is connected to ground.

In some embodiments, the antenna device 500 has two operation modes, an omni-directional mode and a directional mode. In practical applications, the omnidirectional mode or the directivity mode is switched by turning on at least one of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 in the antenna device 500 . For example, all of the PIN diodes D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 and D 8 are turned on to produce an omni-directional radiation pattern. The PIN diodes D 1 , D 4 , D 5 and D 8 are turned on and the PIN diodes D 2 , D 3 , D 6 and D 7 are turned off to produce a radiation pattern as the one propagating toward the upper right of FIG. 5A ; that is, the 45 degree direction as shown in FIG. 1 . The PIN diodes D 3 , D 4 , D 7 and D 8 are turned on and the PIN diodes D 1 , D 2 , D 5 and D 6 are turned off to produce a radiation pattern as the one propagating toward the lower right of FIG. 5A ; that is, the 135 degree direction as shown in FIG. 1 . The PIN diodes D 2 , D 3 , D 6 and D 7 are turned on and the PIN diodes D 1 , D 4 , D 5 and D 8 are turned off to produce a radiation pattern as the one propagating toward the lower left of FIG. 5A ; that is, the 225 degree direction as shown in FIG. 1 . The PIN diodes D 1 , D 2 , D 5 and D 6 are turned on and the PIN diodes D 3 , D 4 , D 7 and D 8 are turned off to produce a radiation pattern as the one propagating toward the upper left of FIG. 5A , that is, the 315 degree direction as shown in FIG. 1 .

In practical applications, when the antenna devices 100 , 200 , 300 , 400 and 500 detect that a user enters a particular beam footprint, the internal switches (e.g., the PIN diodes D 1 -D 8 ) are all switched on to produce an omni-directional radiation pattern. Then, according to the Received Signal Strength Indicator (RSSI) received by the antenna units 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b , some of the internal switches (e.g., the PIN diodes D 1 -D 8 ) are switched on to adjust the beam to orient to the user, to maximize the data rate between the antenna devices 100 , 200 , 300 , 400 and 500 and the user.

In sum, the present disclosure achieves switching radiation patterns via the PIN diodes 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b and a better front-to-back ratio, by disposing the PIN diodes 210 a , 210 b , 220 a , 220 b , 230 a , 230 b , 240 a and 240 b on the transmission lines 201 , 202 , 211 , 212 , 221 , 222 , 231 and 232 in the antenna devices 200 and 300 .

Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.