A two-port mm-wave oscillator

The diversion of a small fractional sample of the main output power is frequently desired. However, devices, such as power dividers or directional couplers, which are commonly used for such a diversion in the case of centimetric wavelengths, are extremely difficult to obtain with low power loss at the shorter millimetric wavelengths. The present investigation is concerned with a two-port mm-wave oscillator which eliminates the need for lossy power dividing components. Tests have been conducted with two types of oscillator cavities. In one type, a simple cap resonator mounted in WG27 waveguide is employed. The same basic design is employed in the second cavity, which, however, is provided with a tuning plunger. Attention is given to oscillator hardware, questions of spectral quality, and preliminary observations with a harmonic two-port oscillator.