A Low-Pass Filter Based on the Slotted-Ground-Plane Horn-Shaped Resonator

Abstract

Designs of a miniaturized low-pass filter (LPF) using the slotted-ground-plane resonator are introduced in this paper. The proposed filter consists of a horn-head slot in the ground plane, two modified arc-head resonators, and a parasitic patch connected at the microstrip line. The horn-head slot, which is a modified type of a horn-shaped slot, provides good band-stop characteristics. To enhance rejection performance, a pair of the modified arc-head slot is embedded inside the hornhead resonator to increase additional transmission zeros into frequency characteristics. Furthermore, a parasitically circular patch is added at the microstrip line for frequency reduction and rejection enhancement. The surface current distributions are presented to explain the resonance mechanism. For the proposed LPF, the measured rejection bandwidth over ¡20 dB is from 1.75 to 12.0 GHz.

Design and analysis of a low‐pass filter utilizing a slotted‐ground‐plane resonator

“…However, a large occupied area is a drawback for a cascade topology design. Recently, the concept of a unit‐cell topology for an SGP LPF has been published . A quasi‐π slot resonator, a meandered‐line, or a horn‐shaped resonator can be used as the main band‐rejection component.…”