Saturday, November 6, 2010

Repeaters

A microwave repeater with antenna isolation comprises a first receiving antenna for receiving an input signal from a distant source.
An amplifier section for amplifying and modulating the input signal to produce an output signal.
A transmitting antenna coupled to the amplifier section and an isolation control means including a second receiving antenna for isolating the first receiving antenna from the transmitting antenna.
In one preferred embodiment, the second receiving antenna is aligned so as to match the gain and phase from the transmitting antenna to the first receiving antenna.
The isolation control means comprises a phase shifter coupled to the second receiving antenna; and a power combiner having inputs coupled to the first receiving antenna and the phase shifter and an output coupled to the amplifier section.
The power combiner receives the input signal from the first receiving antenna and a 1 SO phased shifted signal from the phase shifter.