초록 ▼

A system (10) for remote convenience control of performance of a function includes a portable transmitter unit (14) and a receiver unit (18). In one embodiment, the system (10) is a remote convenience vehicle system. The transmitter unit (14) transmits a signal (16). The signal has a RF frequency at

A system (10) for remote convenience control of performance of a function includes a portable transmitter unit (14) and a receiver unit (18). In one embodiment, the system (10) is a remote convenience vehicle system. The transmitter unit (14) transmits a signal (16). The signal has a RF frequency at an unknown value within a range of values and conveys a message that contains a function request. Within the receiver unit (18) is superheterodyne circuitry (32) that has a mixer (44). The mixer (44) mixes a RF signal (42) coming from an antenna (28) and a reference frequency signal from a reference oscillator (46), and outputs an intermediate frequency signal (50) conveying the message. A bandpass filter (66) filters the intermediate frequency signal to pass a range of frequency values smaller than a known range of intermediate frequency values. Tuning control circuitry (70) automatically adjusting the bandpass range of the bandpass filter (66) to vary the bandpass range over the intermediate frequency range. Passage detector circuitry (72) senses the intermediate frequency signal passing through the bandpass filter (66) and automatically causes the adjustment of the bandpass range to stop.

대표청구항 ▼

[ Having described the invention the following is claimed:] [15.] A remote convenience system for remote controlling performance of a function, said system comprising:portable transmitter means for remote control requests, including means for transmitting a RF signal conveying a message which contai

[ Having described the invention the following is claimed:] [15.] A remote convenience system for remote controlling performance of a function, said system comprising:portable transmitter means for remote control requests, including means for transmitting a RF signal conveying a message which contains a function request, the frequency of the RF signal being at an unknown value within a range of values; andreceiver/controller means for receiving remote control requests and for controlling performance of the requested function, including means for receiving the signal transmitted from said transmitter means and for providing a RF signal having the RF frequency and conveying the message, means for providing a reference frequency signal, means for mixing the RF signal with the reference frequency signal to provide an intermediate frequency signal conveying the message, the frequency of the intermediate frequency signal being at an unknown value within a known range of values, means for bandpass filtering the intermediate frequency signal to pass a range of frequency values smaller than the known range of intermediate frequency values, the bandpass range having a center frequency, means for automatically adjusting the center frequency of the bandpass range of said means for bandpass filtering to vary the bandpass range over the intermediate frequency range, means for sensing the intermediate frequency signal passing through said means for bandpass filtering and for automatically ceasing adjustment of the center frequency of the bandpass range in response thereto.