Automated temperature compensation of linearizers with optimization

Linearizers are electronic circuits which work to counteract the nonlinear behavior of amplifiers. In many of these devices, the dynamic relationship between signal gain and temperature is a naturally occurring phenomenon. Temperature compensation can be achieved by the adjustment of potentiometer values such that an RF output signal more accurately maintains its operating characteristics over a certain temperature range. In many cases, these potentiometer values are set by technicians during the manufacturing process. This requires operation of a temperature plate, vector network analyzer, and linearizer controller software running on a desktop computer. When selecting potentiometer values at each temperature interval, the goal is to maintain minimum change of certain output parameters from those measured at ambient temperature. The goal in this process is essentially to solve a multi-variable combinatorial optimization problem. A technician will make these determinations using heuristics; the results of which can be improved with optimization methods. This paper outlines the design and implementation of the entirely software-controlled automation of the temperature compensation and testing process at Linearizer Technology, Inc. The use of optimization involving linear programming for selecting potentiometer values is also discussed.