Synchronously tuned ferrite power limiter for broad-band systems application

This investigation describes analytical and experimental results obtained on a broadband ferrite limiter at Kuband which utilizes a synchronously tuned waveguide bandpass structure. This device is aimed at providing protection for communications and electronic warfare systems over a bandwidth from 12 to 30 percent at Ku-band frequencies. The circuit consists of a series of three cavities in a waveguide transmission line, the coupling being accomplished via the irises or symmetrical inductive slits between cavities. Because of this cavity structure, the observed threshold power levels have been reduced by an order of magnitude. By utilizing a combination of single crystal YIG and lithium ferrite rods, the threshold power for limiting varies from 0.75 W at 16.0 GHz to 2.0 W at 17.0 GHz with an insertion loss of 0.9 dB.