Local multipoint distribution service (LMDS) transceiver - has receiver, intermediate and transmit stages to phase lock local oscillator to stable low frequency reference signal

摘要

The LMDS transceiver includes a reference source (42) generating a stable low frequency reference signal, a transceiver oscillator (32) generating a transceiver drive signal and a receiver mixer (30), which mixes received modulated signal with a harmonic (39) of the transceiver drive signal, to generate an intermediate frequency received signal. An intermediate transmit oscillator (38), phase locked to the stable low frequency reference signal, generates an intermediate transmit oscillator signal. An intermediate transmit mixer (34) generates an intermediate transmit signal by mixing a transmit modulated signal with a harmonic (45) of the intermediate transmit oscillator signal. Furthermore, the transceiver has a final transmit mixer (40) to generate an output transmit signal by mixing the intermediate transmit signal with a harmonic (41) of the transceiver drive signal. A transceiver drive mixer generates an intermediate phase detect signal by mixing the transceiver drive signal with a harmonic of the intermediate transmit oscillator signal. The intermediate phase detect signal is phase locked with the stable low frequency reference signal.