RF-controlled power saving communication system

The present invention relates to power saving communication systems, and particularly to an RF-controlled (radio frequency controlled) power saving communication system.

The research and development of cellular phones can be generally classified into two main fields. One is how to incorporate more features into a cellular phone (i.e., multifunctional cellular phone), and the other is how to develop better power saving functions so as to increase service time per a fully charged battery.

Currently, the power saving function is typical carried out during waiting operation periods of the cellular phones. Power supply to most parts of the cellular phones is cut off during waiting operation periods and therefore the cellular phones enters into a so-called “sleep state”. However, even though the cellular phones are in the “sleep state”, a small amount of power supply is still maintained to the cellular phones. Such power supply is applied to certain parts of the electronic device, especially to big power consumption devices: CPUs of the cellular phones, in order to rapidly “awaken” the cellular when reusing the cellular phones. Therefore, serious power consumption actually continues even when the cellular phones are in the “sleep state”.

Powering off the cellular phones while not in use is the most effective way of saving power for the cellular phones. However, powering off the cellular phones will disable users to communicate with others.

Therefore, there is a need for providing a RF-controlled power saving communication system which can facilitate users to communicate with others while efficiently saving much more power.

An RF-controlled power saving communication system (hereinafter “the system”) is provided in accordance with a preferred embodiment. The system includes an electronic device, an antenna and a radio frequency (RF) receiver. The RF receiver is for receiving RF signals via the antenna and transmits the RF signals to the electronic device to process. The system further includes a power saving apparatus for controlling power supply of the electronic device. The power saving apparatus receives the RF signals from the RF receiver and resumes the power supply of the electronic device in accordance with the RF signals.

Other advantages and novel features will be drawn from the following detailed description with reference to the attached drawings, in which:

FIG. 1 depicts an exemplary circuit block of an RF-controlled power saving communication system in accordance with a preferred embodiment of the present invention;

FIG. 2 depicts a circuit diagram of the RF-controlled power saving communication system in accordance with the preferred embodiment of the present invention; and

FIG. 3 depicts another circuit diagram of the RF-controlled power saving communication system in accordance with the preferred embodiment of the present invention.

Referring to FIG. 1 , a block diagram of a radio frequency controlled (RF-controlled) power saving communication system (hereinafter simplified as “the System”) is shown. The system can typically be employed in a mobile phone and mainly includes five blocks: a power supply unit 10 , a power saving apparatus 20 , an electronic device 30 , a RF receiver 40 , and an antenna 60 . The power saving apparatus 20 is interposed between the power supply unit 10 and the electronic device 30 , and serves as an intelligent power switch for the electronic device 30 . The electronic device 30 communicates with external data, for example, communicates with a mobile phone via the antenna 60 , or receives commands from a user via input tools. In general, the electronic device 30 is considered to be in a “busy” state when communicating externally; otherwise, the mobile phone 30 is considered to be in an “idle” state.

The electronic device 30 outputs real time signals informing the power saving apparatus 20 of its current state. The real time signals typically include a “normal” signal and an “idle” signal. The “normal” signal indicates that the electronic device 30 is in a “busy” state or in an “idle” state under a predetermined time period, and the “idle” signal indicates that the electronic device 30 has remained in the “idle” state over the predetermined time period. The power saving apparatus 20 discontinues the power supply to the electronic device 30 corresponding to the “idle” signal. The mobile phone 30 is then in a “power off” state, thereby avoiding power consumption thereof.

The RF receiver 40 is interposed between the power supply unit 10 and the power saving apparatus 20 . The RF receiver 40 receives RF signals from an external RF source (not shown), for example from a base station of mobile communication via the antenna 60 . Usually, as known to those skilled in the art, the RF signals are then transmitted to the electronic device 30 for processing. According to embodiments of the present invention, the RF signals are further transmitted to the power saving apparatus 20 , and acts as an “awakening” signal of the electronic device 30 . The “awakening” signal prompts the power saving apparatus 20 to resume the power supply of the electronic device 30 if the electronic device 30 is in the “power off” state. The power saving apparatus 20 thereupon activates the electronic device 30 .

The “awakening” signal, as well as the “normal” signal and the “idle” signal,” are inputted to the power saving apparatus 20 at a node indicated by a symbol A (hereinafter referring as to “the node A”). A first unidirectional conducting unit 51 is interposed between the electronic device 30 and the node A, and a second unidirectional conducting unit 52 is interposed between the RF receiver 40 and the node A. The first and second unidirectional conducting unit 51 and 52 co-operate and prevent communication between the electronic device 30 and the RF receiver 40 via the node A.

Referring to FIG. 2 , in one embodiment, the power saving apparatus 20 generally includes a controlling circuit 210 and a switching circuit 220 , both of which are in a controllable three-terminal form. In this figure, the switching circuit is given as a P-channel Metal Oxide Semiconductor (MOS) (hereinafter, referred to simply as PMOS) Q 1 as an example. The PMOS Q 1 is connected with the power supply unit 10 , the electronic device 30 and the controlling circuit 210 respectively at a drain, a source, and a gate thereof The controlling circuit 220 is given as a N-channel MOS (hereinafter, referred to simply as NMOS) Q 2 as an example. The NMOS Q 2 is connected with the switching circuit 220 , the node A, and a common low-level potential (e.g., the ground potential) respectively at a source, a gate, and a drain thereof The source of the NMOS Q 2 , together with the RF receiver 40 , is connected to the power supply unit 10 via a resistor R. In this embodiment, the first and second unidirectional conducting unit 51 and 52 are all diodes whose cathodes are all connected with the node A and whose anodes are respectively connected with the electronic device 30 and the RF receiver 40 .

NMOS Q 2 receives the “normal” signal from the electronic device 30 . The “normal” signal maintains the gate of NMOS Q 2 at a high-level potential and NMOS Q 2 accordingly turns on (closes) and allows conduction. PMOS Q 1 subsequently turns on as the gate thereof is changed by the conduction of NMOS Q 2 from a high-level potential to a low-level potential (i.e., equaling a value of the common low-level potential).

NMOS Q 2 also receives the “idle” signal from the electronic device 30 . The “idle” signal shifts the gate of the NMOS Q 2 from the high-level potential to a low-level potential, and the NMOS Q 2 accordingly turns off (open circuit), not allowing conduction. PMOS Q 1 subsequently turns off as the gate thereof is changed by the turned-off of NMOS Q 2 from the low-level potential to the high-level potential.

NMOS Q 2 further receives the “awakening” signal from the RF receiver 40 . The “awakening” signal resumes the high-level potential at the gate of the NMOS Q 2 , and NMOS Q 2 accordingly turns on. PMOS Q 1 subsequently turns on as the gate thereof is changed by the conduction of NMOS Q 2 from the high-level potential to the low-level potential, thus to resume power supply of the electronic device 30 .

Referring to FIG. 3 , in this figure, the controlling circuit 210 is formed by two parallel-arranged NMOSs Q 2 and Q 3 , both of which sources are connected with the switching circuit 220 , and drains are connected with the common low-level potential. NMOS Q 2 is controlled by the electronic device 30 using the “normal” signal and the “idle” signal. NMOS Q 3 controlled by the RF receiver 40 using the “awakening” signal.

It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.