Abstract: Disclosed is a dielectric image guide integrated circuit including first and second sections of image guide of preselected cross-sectional areas joined by an image guide transition section of variable cross-sectional area and all mounted on the surface of an image or ground plane. The image guide transition section has a cavity therein for receiving microwave/millimeter wave energy from the first section of the image guide, and this energy is coupled into a diode mounted within the cavity where it is either detected or frequency converted by the diode. Advantageously, the diode may be mounted on a metal cover which is positioned atop the cavity in the waveguide transition section, and it receives its operating bias from a bias pin connection extending through an opening in the ground plane and including a wisker contact to the diode.

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.