Additive Functions Provide A Powerful Tool For T/R Module Modeling

T/R module behavior as a function of RF frequency, temperature, RF power input, commanded phase shift, commanded gain setting, and over a population of modules can be easily modeled using additive functions. Additive function model equations are completely and simultaneously analytic over the entire operating range of all independent variables and provide rapid solutions for response to complex RF waveforms such as amplitude weighted linear FM CHIRP signals and beam side lobes formed by amplitude weighted array illumination. Degradation of ability to resolve close targets of different amplitude due to non-linear transmitter amplifier waveform compression is easily evaluated. Array beam side lobe degradation due to phase shifter errors and transmitter amplifier saturation is also easily evaluated. This paper is a brief tutorial showing the application of additive equations in modeling transmit and receive functions and how easily digital commands to phase shifter and gain control circuits can be incorporated in the models.