Abstract: A microwave diode tuning circuit including am IMPATT diode holder of coaxial form and an adjustable capacitor connected in a parallel resonant circuit by microstrip transmission line. The tuning circuit includes a stabilization network and a bias insertion network. Optionally, the tuning circuit may include a hybrid junction for coupling two such diode tuning circuits together. the diode holder includes an internally-externally threaded sleeve providing means for continuously adjusting, through a limited range, the inductance of the resonant circuit.

Abstract: A typical coaxial circuit which couples a negative resistance diode to the cavity of a power combiner consists of a metallic rod which is biased by a spring against the diode supported by a carrier which is effective to vary the position of the diode along the longitudinal axis of the rod. The rod cooperates with bores in a block to comprise, in series, between the diode and the cavity, a transmission line whose length varies in accordance with diode position, a fixed impedance transformer and a fixed length transmission line.

Abstract: A microwave-integrated-circuit amplifier provides a broadband response in e region of 1-10 GHz. The amplifier includes: a microstrip which provides distributed circuit values for tuning; first and second microwave FETs included in the microstrip and tuned to the upper and lower cutoffs of the bandwidth, respectively; and a non-reciprocal microwave isolator which passes a signal in only one direction and is connected between the first and second microwave FETs.