Noise-optimal control of HEMT LNA's for compensation of temperature deviationsNoise-optimal control of high-electron mobility transistor low noise amplifier (HEMT LNA) bias voltage and current values was achieved at room temperature. The performance metric maximized was the amplifier gain divided by the amplifier input noise temperature, G/T(sub e). Additionally, the feasibility of automating the initial determination of bias settings was demonstrated in the laboratory. Simulation models of an HEMT were developed from available measurement data, installed on a Sun SPARC 1 workstation, and used in investigating several optimization algorithms. Simple tracking-type algorithms, which follow changes in optimum settings if started at or near the global optimum point, produced the best performance. Implementation of the optimization algorithms was performed using a three-stage Field Effect Transistor (FET) LNA and an existing test apparatus. Software was written to control the bias settings of the first stage of the LNA and to perform noise and gain measurements by using the test apparatus. The optimization control was then integrated with existing test software to create a master test and optimization program for test apparatus use.
Document ID
19920020131
Acquisition Source
Headquarters
Document Type
Other
Authors
Maccarley, C. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bautista, J. J. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Willis, P. A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
September 6, 2013
Publication Date
May 15, 1992
Publication Information
Publication: The Telecommunications and Data Acquisition Report 42-109: January-March 1992