Circuit Simulation Model Including Surface Effects in RF Switching PIN Diodes

摘要

PIN diode surface effects can reduce the overall carrier lifetime from its bulk value. Varying surface conditions can be introduced during fabrication or can change over time. This reduction in effective carrier lifetime can increase the on-state resistance of the device, leading to increased insertion loss in series-connected circuits. This paper builds on a method of discretizing the PIN diode structure into a parallel combination of diode cells, each with their own carrier lifetime to model the bulk or surface conditions at that cell's location. As new reconfigurable structures are being developed for applications such as 5G, this type of circuit model will help PIN diode circuit designers more accurately model the diode's impact on circuit performance. Theoretical modeling of the transport equations is used in conjunction with the model construction. Simulation of a series reflective PIN diode switch using this model show that variations of several tenths of a dB insertion loss variation can be expected as surface conditions change. Simulations are verified with measurements to confirm the concept.