Authors: C.S. Tsai, G. Qiu, H. Gao, G.P. Li, L.W. Yang and S.A. Nikitov
Affilation: University of California, Irvine, United States
Pages: 173 - 175
Keywords: tunable microwave band-stop and band-pass filters, YIG/GGG-GaAs layer structures, ferromagnetic resonance
Future wideband communication and radar systems require high-speed electronically-tuned wideband microwave band-stop and band-pass filters. Ferromagnetic resonance (FMR)-based microwave devices possess the unique capability of high-speed electronic tunability, using magnetic field, for very high carrier frequency and very large bandwidth. In this paper, low-loss magnetically tuned wideband microwave band-stop and band-pass filters using yttrium iron garnet / gadolinium gallium garnet-gallium arsenide (YIG/GGG-GaAs) layer structures are reported. The transmission characteristics of both the stop-band and pass-band filters were measured across the entire bandwidth of 1.0 to 30.0 GHz. For example, the measured transmission characteristics of the band-pass filter at the passband center frequency of 7.1 GHz shows a 3 dB bandwidth of 1, 450 MHz, out-of-band rejection of 33dB, and an insertion loss of 1.5 dB. A good agreement between the experimental results and the simulation results has been achieved. It should be noted that the out-of-band rejection and the width of the stop-band at the two end frequencies can be greatly increased using the microstrip meander line and the nonuniform magnetic field, respectively. The resulting band-pass filters should find applications in frequency-hopping microwave communication and signal processing systems.