Title :
Gain and stability models for HBT grid amplifiers
Author :
Cheh-Ming Liu ; Sovero, E.A. ; De Lisio, M.P. ; Moussessian, A. ; Rosenberg, J.J. ; Rutledge, D.B.
Author_Institution :
Dept. of Electr. Eng., California Inst. of Technol., Pasadena, CA, USA
Abstract :
A 16-element heterojunction bipolar transistor (HBT) grid amplifier has been fabricated with a peak gain of 11 dB at 9.9 GHz with a 3-dB bandwidth of 350 MHz. We report a gain analysis model for the grid and give a comparison of the measurement and theory. The measured patterns show the evidence of a common-mode oscillation. A stability model for the common-mode oscillation is developed. Based on the stability model, a lumped capacitor gives suitable phase shift of the circular function, thus stabilizing the grid. A second 18-element grid was fabricated, using this theory, with improved stability.
Keywords :
capacitors; circuit oscillations; circuit stability; equivalent circuits; gain measurement; heterojunction bipolar transistors; microwave oscillators; microwave power amplifiers; semiconductor device models; 11 dB; 16-element HBT grid amplifier; 18-element grid amplifer; 3-dB bandwidth; 350 MHz; 9.9 GHz; HBT grid amplifiers; SHF; circular function; common mode oscillation; gain analysis; gain model; heterojunction bipolar transistor; lumped capacitor; measured patterns; measurement; peak gain; phase shift; stability model; Capacitors; Dielectric constant; Dielectric substrates; Heterojunction bipolar transistors; Inductors; Polarization; Power amplifiers; Space technology; Stability; Transmission lines;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1995. AP-S. Digest
Conference_Location :
Newport Beach, CA, USA
Print_ISBN :
0-7803-2719-5
DOI :
10.1109/APS.1995.530256
