Patent ID: 6597897
Filing Date: 2003-07-22
Classification: B60R,G07C,H03G

Abstract:
A low power remote transmitter for use in a vehicle remote keyless entry system comprising:a signal transmitter circuit portion including an input for receiving data to be incorporated into a radio frequency signal and an output for transmitting said radio frequency signal to a remote receiver of the entry system, said output including a transistor having a base node, a collector node and an emitter node, said signal transmitter circuit portion further including an oscillator connected to said base node, said oscillator being for generating a radio frequency signal to be transmitted; an inductor having a first end and a second end, said inductor first end connected to said collector node of said transistor; a power supply connected to said second end of said inductor, said inductor being operative as an antenna to radiate said radio frequency signal; and a gain control circuit for controlling a gain associated with said signal transmitter circuit portion so as to reduce power consumed by said remote transmitter, said gain control circuit being connected to said transistor emitter and collector nodes and including an inductive load that introduces a resonant frequency that controls the gain associated with said signal transmitter circuit portion by controlling power at the resonant frequency when generating the radio frequency signal to be transmitted.