Research on Linearity Improvement of Silicon-Based p-i-n Diode Limiters

The threshold is a key indicator of linearity for limiters. However, the threshold of silicon-based p-i-n diode limiters drops rapidly at low frequencies. This letter presents a novel method to improve the threshold of limiters for protecting analog-to-digital converters. A silicon-based p-i-n diode and a zener diode were stacked as a thicker p-i-n diode. Three 30–300-MHz limiters using the same p-i-n diode and different zener diodes were designed. Both the simulated and measured results are presented to verify this method. The results show that the thresholds were improved by 12, 19, and 21 dB, respectively.