MICROWAVE DIODE RESEARCH.
Quarterly progress rept. no. 4, 10 Mar-9 June 63,
BELL TELEPHONE LABS INC MURRAY HILL N J
Pagination or Media Count:
Improved control over epitaxial film thickness, coupled with refinements in diffusion, contracting, and packaging procedures, has resulted in the development of epitaxial GaAs varactors of unusually high performance. Dynamic quality factors over 14.0 at 5.85 gc are routinely achieved with surface barrier models while values around 12 typify the diffused units. For both structures, measured effective noise temperatures are in excellent agreement with the observed dynamic quality factors. The lowest effective noise temperatures observed to date for diffused and surface barrier varactors are 26 K and 20 K respectively degenerate, double-channel, at 5.85 gc and room temperature. These varactor units, which employ epitaxial films one micron thick and junction diameters of about one mil, typically have a junction capacitance of 0.5 pf, reverse breakdown of 12 volts, and zero-bias wafer cut-off frequency of 300 to 500 gc. Author