A compact bandpass filter is designed using stepped impedance ring resonators with zero-degree feed structure.This compact bandpass filters using FR4 and high-permittivity ceramic substrates (with respective dielectric constants of 4.5 and 13.46) are investigated. Using high Q, high permittivity dielectric ceramic materials as substrates, the filters demonstrate high selectivity, compact size, and can be applied in several microwave communication systems. An electromagnetic simulator is used to design the ring resonators, and to calculate the coupling coefficient of the basic coupling strictures. A precise planar bandpass filter with ceramic substrates has been fabricated using the screen printing technique. The responses of bandpass filters using FR4 (εr = 4.5, tan δ = 0.015) and Mg4Nb 2O9 with 0.75 wt% Fe2O3 (εr = 13.46, tan δ = 0.00004) ceramic substrates are designed at a center frequency of 2.4 GHz with bandwidth of about 9%. The compact size, low-loss, and performance of the filter are demonstrated in this article.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering