A High Performance Miniature 8.2 GHz Band Pass Filter Using Multilayer IPD Inductor for UWB and 5G Radio Applications

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Abstract

This paper describes the simulation and fabrication of a miniature onchip Bandpass Filter (BPF) using the Integrated Passives Device (IPD) process for UWB and 5G Radio Frequency Front End (RFFE) solutions. Technology driven miniaturization led to regular geometry shrinking for components and ICs also. A novel high quality series stacked double split path inductor is developed with minimum onchip area. The proposed novel double split (2_split) IPD inductor showed excellent improvements of 53.2% and 36.67% of inductance and quality factor respectively, against the nearest matching inductor in Table 1. A planar high performance spiral capacitor is modeled to design a simple low cost first order LC resonator BPF circuit. The 8.2 GHz BPF simulated using High Frequency Simulation Software (HFSS), yielded very good performance enhancements: Q factor of 13.68, smaller 7.31% fractional bandwidth, very low -0.25 dB insertion loss, -26 dB return loss and finally very small chip space of only 0.144 mm2. This proposed IPD BPF demonstrated very narrow bandwidth yet occupying least possible footprint. These IPD passives are fabricated by scaling down to mm scale due to PCB fabrication difficulty at nm scale. The mm level downscaled and fabricated LC resonator BPF is tested on Agilent network analyzer (VNA-N9923A). The PCB measured results of the BPF are in very good concurrence with simulation results. The proposed compact 8.2 GHz BPF performance is validated from above successful results. All these superior parameter enhancements clearly prove that the proposed 8.2 GHz BPF using the novel 2_split inductor, is highly suitable for Radio Frequency Integrated Circuit (RFIC) applications at 8 GHz UWB band.

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Keywords

BPF; HFSS; Insertion Loss; IPD; Multilayer; Quality factor; RFFE