US 5,493,583 A · Wireless data transceiver

Abstract

A full duplex data transceiver for transmitting and receiving frequency-modulated ("FM") signals representing binary data includes separate transmit and receive antennas, and a single oscillator which serves as both the radio frequency ("RF") signal source for the transmitter and the local oscillator ("LO") signal source for the receiver. During signal transmission, the oscillator output is frequency-modulated to provide a FM transmit signal to the transmit antenna. The oscillator output is frequency-modulated with binary transmit data by modulating an error feedback signal which serves as the control voltage for a voltage-controlled oscillator in a phase-lock-loop, thereby producing the FM transmit signal. During signal reception, the oscillator output, in the form of the transmitted FM signal, is received via the receive antenna along with a FM receive signal for mixing therewith to down-convert the FM receive signal. As part of the demodulation of the down-converted FM receive signal, the binary transmit data is subtracted out.

Claims23

Dependent claims

A data transceiver for transmitting and receiving modulated radio frequency (RF) signals, comprising:

a transmitter antenna;
a receiver antenna;
transmitter means coupled to said transmitter antenna for receiving a first modulation signal M1 and generating a second modulation signal M2 therefrom, generating a RF signal having a first carrier frequency F1, modulating said RF signal in accordance with said first modulation signal M1 and transmitting via said transmitter antenna said modulated RF signal as a first modulated RF signal;
and
receiver means coupled to said receiver antenna and said transmitter means for receiving via said receiver antenna a second modulated RF signal having a second carrier frequency F2 modulated by a third modulation signal M3, receiving via said receiver antenna said transmitted first modulated RF signal and mixing said received first and second modulated RF signals to produce a modulated intermediate frequency (IF) signal having a modulated center frequency F3 equal to a difference .uparw.F1-F2.vertline. between said first carrier frequency F1 and said second carrier frequency F2, and for receiving said second modulation signal M2 and in accordance therewith demodulating said modulated IF signal.

2 more elements

A data transceiving method for transmitting and receiving modulated radio frequency (RF) signals, comprising the steps of:

receiving a first modulation signal M1 and generating a second modulation signal M2 therefrom;
generating a RF signal having a first carrier frequency F1;
modulating said RF signal in accordance with said first modulation signal M1;
transmitting said modulated RF signal as a first modulated RF signal via a transmitter antenna;
receiving via a receiver antenna a second modulated RF signal having a second carrier frequency F2 modulated by a third modulation signal M3;
receiving via said receiver antenna said transmitted first modulated RF signal;
mixing said received first and second modulated RF signals to produce a modulated intermediate frequency (IF) signal having a modulated center frequency F3 equal to a difference .vertline.F1-F2.vertline. between said first carrier frequency F1 and said second carrier frequency F2;
and
receiving said second modulation signal M2 and in accordance therewith demodulating said modulated IF signal.

6 more elements

Dependencies are inferred from the claim text.

Wireless data transceiver

Life of this patent

Wireless data transceiver

Life of this patent

Abstract

Claims23