Gallium arsenide hyperabrupt tuning varactors

Hyperabrupt gallium arsenide tuning varactors have been constructed using vapor phase grown epitaxial gallium arsenide of low-high-low doping profile. Both platinum Schottky and p-n junction devices have been studied. The varactors have exhibited 50 MHz Q at 4 volts reverse bias in excess of 5000, tuning ratios from zero bias to breakdown in excess of 13 to 1, and have been useful in providing linear tuning of an X-band Gunn diode voltage controlled oscillator (VCO). Fine grain tuning linearity and harmonic generation have been studied.