Modeling of Microwave Rectification RFI Effects in Low Frequency Circuitry+

This paper discusses the rectification response exhibited by low frequency bipolar transistors when microwave energy is injected. A circuit analysis model for calculating low frequency small signal response to microwave energy is discussed and applied in analyzing the behavior of a 741 op-amp. non-uniformity of gain across the emitter. In an emitter follower circuit such as that which appears at the 741 input, the principle circuit response is due to the emitter-base offset voltage, which may be calculated from knowledge of device material and geometrical factors. Quantitative theoretical calculations are performed to relate the response of a small NPN transistor similar to that used in a 741 op-amp to its material and geometrical parameters.