PIN Diode Weight Circuits.
MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
Pagination or Media Count:
This report is one of a number of technical notes describing various aspects of the design, fabrication, and performance of a demonstration analog feedback processor. In this report we examine the PIN diode weight circuits which are used in the adaptive processor to control the attenuation and phase of the eight signal channels which make up the processor. The weighting circuits are required to have well-matched transfer functions which track closely from channel to channel so as not to degrade the processor cancellation. To achieve the necessary tracking performance, two different weight circuit designs were investigated. The tracking performance of the first set was found to be limited by the direct feed-through of input signals to the output of the weight circuit as a result of the limited dynamic range of the weight circuit attenuator. To overcome this limitation, a second set of weight circuits having significantly improved tracking characteristics was fabricated using an improved attenuator circuit design. Information relevant to the design, fabrication and testing of each weight circuit is presented along with measured data to demonstrate its performance. Techniques used in characterizing the frequency tracking performance of multiple weight circuits are discussed and measurement data is presented to illustrate the relative tracking performance of the weight circuits. Author
- Electrical and Electronic Equipment