Design Consideration for High-Isolation Coaxial Broad-Band p-i-n Diode Switches and Limiters

Broad-band coaxial p-i-n diode switches and limiters are realized using a low-pass filter structure in which shunt capacitances are realized by the capacitances of reverse- or zero-biased p-i-n diodes. Usually, the design considerations are given only for insertion-loss state. No design guideline exists in the literature to optimize isolation for these type of switches and limiters. This paper shows that using low-pass filter structure with series inductance as the first element, higher isolation without increasing insertion loss can be achieved.