A highly temperature stabilized K-band (18-26.5 GHz) Gunn VCO for high capacity digital radio systems

Gunn oscillators have been designed for use in a quaternary phase shift key (QPSK) high capacity digital data link radio system, operating over the 17.7 to 19.7 GHz region, which exhibit a high degree of frequency stability with no detectable phase hit characteristics over a wide temperature range (-20 degrees C to +70 degrees C). The basic design incorporates a single Gunn diode, an electronic tuning varactor used with AFC to control the frequency and a second frequency modulation varactor. This latter varactor provides a service band facility and engineers order wire (EOW) information which is frequency modulated with low frequency signals on the transmit oscillators. A continuous mechanical tuning capability required for channel selection over a nominal 770 MHz bandwidth, is also included in this design.<
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