Photo-injection PIN diode switch for high power RF switching

The RF high power switching properties of an optically controlled RF switch, the photo-injection PIN switch (PIPINS), are investigated. Proper functioning of a PIPINS as a low insertion loss RF switch requires that it operates as a photoconductor, where the photo-injected charge is much greater than the RF sweep out charge. Insertion loss using 650 mW optical power was <0.4 dB at RF (VHF-UHF) power in excess of 200 W, isolation is determined by the device capacitance (e.g., 225 fF). PIPINS hot switching measurements are reported with output RF power up to 180 W at low duty cycle, rise times of 1 μs, and fall times for a series shunt switch of ≈ 2.5 μs. The RF power for hot switching a PIPINS is limited by a latch-on effect likely caused by thermally generated carriers. The switching properties of PIPINS make them a candidate for RF high power applications such as reconfigurable antennas, where electromagnetic isolation of the switch and control lines are critical.