Design of New Compact Multi-Layer Quint-Band Bandpass Filter

Yi-Wen Chen,Haitao Ye,Yung-Wei Chen,Hung-Wei Wu,Ran Liu,Shih-Kun Liu

doi:10.1109/access.2021.3116807

Abstract

In this paper, we propose the new compact multilayer quint-passband bandpass filter. The multilayer substrate technique is used for further miniaturizing the circuit size. The filter has quint passband at 1.8, 2.5, 3.3, 3.8 and 4.5 GHz. Coupled resonators such as the stepped impedance resonators (SIRs), stub-loaded uniform impedance resonators (UIRs), and quarter-wavelength uniform impedance resonators are applied to produce the quint-passband of the filter simultaneously. The stub-loaded uniform impedance resonators and stepped impedance resonators can easily obtain a filter with closed passbands. Using a multilayer substrate technique, the filter can provide multipath propagation to improve the frequency response and achieve a compact circuit size. The proposed quint-passband bandpass filter shows a simple configuration, a practical design method, and a small circuit size.

Highlights

Planar multiband bandpass filters (BPFs) with compact size, low insertion losses, high passband selectivity, and fixable frequencies have become the critical component in front-end radio frequency (RF) applications used in rapidly developing multiservice and multifunction wireless communication systems.Some methods demonstrating the new multiband bandpass filters have been reported [1]–[6]
In this paper, we propose the new compact multilayer quint-passband bandpass filter
The multilayer substrate technique is used for further miniaturizing the circuit size

Summary

INTRODUCTION

Planar multiband bandpass filters (BPFs) with compact size, low insertion losses, high passband selectivity, and fixable frequencies have become the critical component in front-end radio frequency (RF) applications used in rapidly developing multiservice and multifunction wireless communication systems. The filter features use a multilayer technique to reduce the circuit size and provide a closed quint-passband BPF with high in-band isolation and adequate passband selectivity. As demonstrated in this study, the even and odd modes of the stub-loaded UIRs and SIRs can be controlled individually, resulting in the quint-band filter having very close passbands. The even modes of the proposed stub-loaded UIRs can be tuned within a wide frequency range without affecting the odd modes This design of multiband filters with close passbands clearly has high isolation between the passbands. The transmission zero locations at skirts of each passband are associated with the coupling strength of the interdigital sourceload line; the passband selectivity can be controlled

This work

RESULTS

CONCLUSION