Filter stabilized single oscillator transceivers

DETAILED DESCRIPTION Having thus described a typical embodiment of my invention, that which I claim as new and desired to secure by Letters Patent of the United States is: 1.
A transceiver, adapted for use in a duplex transceiver system including a pair of such transceivers settable for operation with one in a master mode and one in a slave mode, said transceiver comprising: a single, voltage-tunable oscillator having means for providing a frequency-controlling voltage input thereto; an FM receiver having the same IF frequency in the master mode as in the slave mode and including an RF mixer that drives said FM receiver and that provides a frequency-determining feedback signal; antenna means for transmitting and receiving microwave energy; an RF filter, having a center frequency and having a pass band greater than said IF frequency, the output of said RF filter coupled to said RF mixer; means for coupling energy from said oscillator to said antenna means for transmission thereby and for simultaneously coupling energy received at said antenna means and a small portion of the energy of said oscillator to the input of said RF filter; and frequency control means including means providing an initial frequency sweep controlling voltage to the input of said oscillator to thereby sweep the frequency of said oscillator to a frequency within said band of frequencies, and having an input connected for response to the feedback signal output of said RF mixer, for providing a frequency control voltage to the frequency-controlling voltage input means of said oscillator in response to said feedback signal and to said initial frequency sweep controlling voltage to establish operation of said oscillator at a frequency separated from said center frequency by one half of said IF frequency, and further including means settable to designate said transceiver for operation in the master mode or the slave mode, and operable when set in the slave mode to provide said frequency control voltage to establish operation of said oscillator at one side of said center frequency and operable when set in the master mode to provide said frequency control voltage to establish operation of said oscillator at the other side of said center frequency