Reverse biased PIN diode equivalent circuit parameters at microwave frequencies

This paper attempts to fulfill the need for a quantitative analysis of the microwave equivalent steady state circuit parameters of the reverse biased PIN diode as a function of the process variables of the unit. The process variables considered include the effects of small impurity concentrations in the I region and variations in diffusion depth, surface dopant concentration, and I region width at the microwave frequency of 1 Gc/s. Using the Q of the diode as a result of a given design, it is shown that a high Q depends on having a small width, high resistivity I region, along with a shallow diffusion depth. The equivalent circuit parameters are independent of surface dopant concentration to a first approximation.