A new circuit for stabilizing frequencies of low noise millimeter wave oscillators

A new circuit for low noise cavity stabilized millimeter wave oscillators has been developed. The circuit consists of stabilizing H/sub 011/ cavity, /spl lambda//sub g//4 electrical length transmission line, diode section and load. The diode section has a series resonance at the working frequency. To test the circuit, the 42 GHz GaAs IMPATT diode oscillator has been developed and investigated. The oscillator showed the phase noise reduction factor of about 50 dB. The noise level was at -89 dBc (1 Hz) at the 1 kHz offset frequency.