Hyperabrupt Varactor Voltage-Controlled Oscillators
Abstract
A method for fabricating and processing plated heat sink hyperabrupt gallium arsenide varactors for use in microwave voltage-controlled oscillators was developed and evaluated during this program. VCOs fabricated with these varactors demonstrated considerably improved linearity and reduced tuning voltage requirements as compared with VCOs fabricated with conventional abrupt junction varactors. During the program, hyperabrupt gallium arsenide varactor wafers were grown in which values of gamma from 0.5 to 2.0 were obtained and capacitance ratios as high as 30:1 were measured. In most cases, the carrier concentration profiles necessary to obtain the various hyperabrupt characteristics obtained were grown epitaxially by the hydride vapor synthesis technique using a programmed controller to introduce dopant at the required rates. The process was proven to have the capability to grow wafers which closely matched a desired profile. Because of the versatility of this controlled back-doping process, complicated structures can be grown such as the p(+)-n(o)- n(+)-n-p(+) GaAs wafers which were used to produce electrolytically etched varactor diodes with integral heat sinks. These plated heat sink mounted varactors proved to have very low post tuning drift characteristics in VCOs compared with conventionally mounted GaAs varactors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1977
- Accession Number
- ADA047522
Entities
People
- D. D. Mawhinney
- J. J. Napoleon
Organizations
- Sarnoff Corporation