Design of a low-profile high-selectivity filtering dense dielectric patch antenna

• Published in: Chinese journal of physics (Taipei) Vol. 77; pp. 2490 - 2500
• Main Authors: La, Dong-Sheng, Zhang, Chao, Zhang, Yu-Jiao, Mi, Rong-Qi, Qu, Mei-Jun, Guo, Jing-Wei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2022
• Subjects: Dense dielectric patch antenna; Filtering; High-selectivity; Low-profile; Radiation null; Low-profile; High-selectivity; Filtering; Radiation null; Dense dielectric patch antenna
• ISSN: 0577-9073
• DOI: 10.1016/j.cjph.2022.02.015

In this paper, a filtering dense dielectric patch (DDP) antenna (DDPA) with low-profile and high-selectivity is proposed with thickness of 0.024λ0. By etching an annular gap in the DDP, not only the TM11 mode and TM12 mode are successfully adjusted to the adjacent frequency, but also the high-order harmonics are suppressed. Consequently, both of the operating bandwidth and stopband bandwidth of the proposed DDPA can be enhanced. To improve the skirt selectivity, an adjustable radiation null (RN) is introduced at the lower edge of the passband by using a cross-shaped microstrip feed structure. Due to the mutual coupling between the cylindrical DDP and annular DDP, another adjustable RN is introduced at the upper edge of the passband. Hence, the proposed DDPA can realize the filtering function without additional filtering circuit. For demonstration, a prototype is fabricated and measured. The measured results prove that the proposed design has a relative impedance bandwidth of 8.6% (3.44–3.75 GHz), a peak gain of 8.1 dBi and a high roll-off rate of 180.8 dB/GHz. The proposed design has great application prospects in modern wireless communication system. •A gap in DDP can adjust multiple modes and widen passband.•The mutual coupling of two DDPs can generate a radiation null.•Silver arcs on DDP can adjust the radiation null and obtain wide stopband.•Two radiation nulls are introduced and the skirt selectivity is improved.