Active magnetostatic wave delay line for microwave signals

Summary form only given. Three variants of a new active magnetostatic wave (MSW) delay line for pulsed microwave signals providing controlled delay times of up to 1 /spl mu/s has been developed and experimentally tested. The proposed active delay line consists of an input and output transducers, yttrium-iron garnet (YIG) film waveguide (where the microwave MSW pulse is propagating), and an open dielectric resonator which is situated between the transducers and is used to supply electromagnetic pumping pulses having frequency (9.4 GHz) twice as large as the carrier frequency of the input microwave radio-pulse (4.7 GHz). In contrast with the usual passive MSW delay line, where characteristics are controlled by the external bias magnetic field, the characteristics of the developed active delay line are controlled by the amplitude, duration, and the moment of application of the pumping pulse. While traditional passive MSW delay lines have substantial insertion losses proportional to the delay time (/spl sim/ 80 dB//spl mu/s), in the developed active delay line the amplitude of the output delayed pulse can be kept constant in the whole interval of possible time delays.