Integrated non-reciprocal dual H- and E-Field tunable bandpass filter with ultra-wideband isolation

The integrated non-reciprocal tunable bandpass filter with a NiZn ferrite film deposited via a spin sprayed process is presented. With external in-plane magnetic fields from 100 to 400Oe, the central frequency was tuned from 3.78 to 5.27GHz, with an insertion loss of 1.73 to 3.42dB and an in-band isolation of more than 13 dB, which was attributed to the non-reciprocity characteristics of the magnetostatic surface wave. By attaching the BPF on a PMN-PT slab, it can perform a voltage tunable behavior by magnetoelectric coupling. Frequency tunabilities of 500MHz/100Oe and 55MHz/1(kV/cm) are achieved. This design with dual functionality of integrated tunable bandpass filters and an UWB isolator can lead for compact, low-cost and power-efficient RF communication systems on RFIC and MMIC.