The effect of temperature variation on the transient response of RF PIN diode limiters for very high frequency applications

This work presents the effect of temperature change on the capacitance of silicon PIN diodes and the resulting change in performance of RF limiters at very high frequency (VHF). Device temperatures were varied between −25 ºC and 100 ºC, with small-signal parameters (including device capacitance) extracted at regular temperature increments and bias voltages from −20 Vdc to +3 Vdc using a multi-bias parameter extraction method. It was found that the junction capacitance of the four PIN diodes under investigation increases with temperature, as expected from carrier lifetime behaviour, while results also confirmed prior observations of an inverse relationship between forward-biased series resistance and temperature. Devices were subsequently tested in two different limiter topologies through high-power transient measurements. It was found that the combination of increased capacitance and decreased resistance with increasing temperature increases the transient spike leakage and decreases the flat leakage of a limiter. It was also concluded that, for VHF, an anti-parallel topology provides the best performance over a wide range of temperatures.