Low‐Profile Broadband Magneto‐Electric Dipole Filtering Antenna Utilizing Shared‐Edge C‐Shaped Slot Structure

ABSTRACT In this paper, a magneto‐electric dipole (MED) filtering antenna with a novel filter feed network is proposed. The proposed antenna is based on the low‐temperature cofired ceramic (LTCC) process. The MED antenna has an intrinsic radiation null, and a mathematical model of the magneto‐electric dipole is presented to elucidate its working mechanism. An innovative shared‐edge C‐shaped slot structure has been implemented on the ground plane to form a novel filter feed network. The configuration employs two adjacent C‐shaped slots of different dimensions sharing a common edge, achieving significant space reduction. At certain specific frequencies, the energy concentrates in the shared‐edge C‐shaped slots and does not couple to the radiation patches, causing radiation nulls. To analyze this principle, equivalent circuits of the novel filter feed network are provided. The proposed antenna has a total of four controllable radiation nulls with excellent out‐of‐band rejection. For verification, a MED filtering antenna is designed, fabricated, and experimentally validated. The measurement results indicate that the antenna has an impedance bandwidth of 21.7% (11.9–14.8 GHz), an average gain of 5.0 dBi in the passband, and the out‐of‐band suppression level is better than 20 dB.