Abstract: A double heterostructure step recovery diode having a very fast step transition time and a high output voltage. A highly doped, wide bandgap p-type region; a narrow bandgap intrinsic region; and a highly doped, wide bandgap n-type region define a PIN diode structure. The intrinsic region forms heterojunctions with the p and n regions. Highly doped, narrow bandgap p and n contact regions adjoin the wide bandgap p and n regions, respectively and form heterojunctions therewith. Very thin, highly doped, narrow bandgap p and n regions are located between the intrinsic region and the wide bandgap p and n regions, respectively. Optional graded bandgap p-type and n-type regions are located between the wide and narrow bandgap p and n regions. In one embodiment the diode is embedded in an undoped wide bandgap material. In an alternate version, the intrinsic region is replaced with a lightly-doped p-type charge storage region to reduce the slow tail portion of the step recovery.

Abstract: A travelling wave modulator that modulates the phase velocity of an electromagnetic travelling wave in response to travelling wave electrical signal travelling parallel to the electromagnetic wave. The physical parameters of various layers in the modulator are selected to optimize a figure of merit of the modulator. Suitable figures of merit are bandwidth, bandwidth to voltage V.sub..pi. ratio and difference in velocity between the electrical signal and the electromagnetic travelling wave.

Abstract: A Monolithic Sampler is disclosed. The present invention overcomes the problem of inadequately low sampling rates that results from circuit designs or component limitations that constrain the bandwidths of previous instruments. The sampler includes five circuit stages: a local oscillator section that may be used to drive the system, a shock wave generator that produces high frequency edge-sharpened pulses, a reflection damping clamping section, a delay section, and a sampler section regulated by the stream of shock waves which produces an IF output. The local oscillator or a pulse generator (not shown) produces an input that propagates down a nonlinear transmission line. Once this input reaches the shock wave generator section, it encounters a series of hyperabrupt diodes which are employed as voltage dependent capacitors called varactors. These varactors deform the input pulses and generate a stream of spike-shaped waveforms known as shock waves.