Patent ID: 7321753

Claim:
A wireless transmission circuit enabling modulation of RF power amplification, comprising: a signal modulator-oscillator circuit for receiving and modulating a signal data output by a signal processing circuit; a cascade power amplification circuit including a plurality of power stages for receiving a signal data modulated and output by said signal modulator-oscillator stage, and power of said received modulated signal data being amplified at one or more of said plurality of power stages; and a power-setting unit for setting a specific number of said power stages in said cascade power amplification circuit to be included in said power amplification of said received modulated signal according to a required transmission power and a transmission distance; and said signal data having been power-amplified at said one or more power stages being further processed and then emitted at an antenna to be received by a remote reception device; wherein said signal processing circuit may be a signal processing circuit for any one of a mouse, a keyboard, a joystick, a track ball, a game controller, a digital signal camera/PC camera, and a digital signal video camera/PC video camera for generating said signal data; wherein said signal data having been power-amplified at said one or more power stages is further processed with a filter circuit and then emitted at said antenna; and further wherein said power-setting unit includes at least one power switch and at least one bypass switch, and said bypass switch is in a number corresponding to that of said power switch; said at least one power switch being serially connected to a power input of a corresponding one of said power stages to decide whether said corresponding power stage is supplied with a power, and said at least one bypass switch being connected in parallel to said corresponding power stage between an input and an output thereof to serve as a bypass for said signal; and said power switch and said bypass switch for the same one of said power stages being complementarily switched on or off.