FR-4 Embedded UWB Filter using Impedance Resonator
In this paper, a novel embedded ultra wideband (UB) band-pass filter is presented on a FR-4 package substrate including high Dk resin coated copper (e,=30) film. The proposed UWB filter is comprised of a parallel resonator with meander-type uniform impedance resonator (UIR) and two series resonators with high Q circular stacked spiral inductor and metal-insulator metal (MIM) capacitor. In order to obtain excellent attenuation characteristies by generating attenuation poles in lower and upper stop bands, a single MIM capacitor is added to each resonator. The fabricated FR-4 embedded UWB filter has insertion loss of -1.0dB and return loss of -11dB, respectively. It has also extremely wide bandwidth (over 50%) and small size (3.7 × 4 × 0.77 m) which is compatible with LTCC devices.