Abstract: Disclosed is microwave oscillator or amplifier circuitry which is tunable over a wide bandwidth and which includes an improved variable loading on a negative resistance semiconductor diode, such as an IMPATT diode. This loading is provided in mutually perpendicular directions closely adjacent the diode. In one direction, a DC bias connection is mounted together with an adjustable coaxial filter thereon, and this filter serves as a series tuning element for the diode. A movable short is mounted for adjustment in a direction perpendicular to that of the above coaxial filter and provides parallel tuning for the diode. These series and parallel tuning elements are operative to match the real and imaginary components of the diode impedance to the real and imaginary components of the load impedance, respectively, at a particular operating frequency, thereby maximizing the power transfer and the DC to RF conversion efficiency of the circuitry.

Abstract: Disclosed is a microwave power accumulator including a plurality of coaxial oscillator circuits, each tightly coupled to a single common output combining resonant cavity. Each of the coaxial circuits includes a negative resistance diode at one end and a lossy terminating (microwave absorbing) material at the other end which absorbs and suppresses resonant modes within each coaxial circuit. This feature enables the cavity resonance of the common output combining cavity to dominate all of the individual coaxial circuits spaced therearound. The spacing of these coaxial circuit modules around a common cylindrical output combining cavity permits a high packing density and good individual heat sinking for the accumulator.