A low-profile circularly polarized microstrip antenna using elliptical electromagnetic band gap structure

This study investigates a low-profile circularly polarized (CP) antenna using coplanar waveguide feeding. Rectangular-shaped slots and an inverted L-shaped slit are entrenched into the ground plane to enhance the impedance bandwidth of the antenna. Furthermore, the antenna is implemented with six elliptical electromagnetic band gap structures on its substrate to enhance the −10 dB return loss bandwidth and also to generate CP waves. The experimental and theoretical results closely match each other and indicate that a simple and compact design antenna with dimensions of 0.317λ0 × 0.317λ0 × 0.023λ0(λ0 is the operating wavelength at 4.74 GHz in free space) achieves 36.9% (3.91–5.68 GHz) of the −10 dB return loss bandwidth and 9.98% (4.09–4.52 GHz) of the 3-dB axial ratio bandwidth, thus making it a favorable entrant for radio altimeter and wireless avionics infra-communication systems.

Desain Antena Mikrostrip UWB dengan Peningkatan Lebar pita dan Karakteristik Triple Notch Band

Antena Ultra-Wideband (UWB) dengan karakteristik natural pita lebar adalah solusi yang baik dalam memenuhi kebutuhan perkembangan teknologi nirkabel yang saat ini membutuhkan antena yang dapat beroperasi pada beberapa pita layanan sekaligus. Namun, antena UWB tidak terlepas dari permasalahan interferensi elektromagnetik pada beberapa layanan yang tidak digunakan. Oleh karena itu, diperlukan modifikasi pada antena UWB agar dapat mengatasi permasalahan interferensi elektromagnetik tersebut. Dalam makalah ini, perancangan antena mikrostrip UWB berbentuk heksagonal monopole planar dengan karakteristik peningkatan lebar pita menggunakan struktur Electromagnetic Band Gap (EBG) dan triple notch band dengan menggunakan tiga jenis slot telah dilakukan. Pengujian dilakukan dengan mengintegrasikan struktur EBG untuk dapat bekerja pada rentang lebar pita 2,8–16 GHz pada antena, lalu menambahkan kombinasi slot berbentuk huruf L, slot horizontal, dan slot melingkar dengan ukuran dimensi yang berbeda ke dalam patch untuk mendapatkan penolakan tiga pita frekuensi, yaitu pada frekuensi WLAN (4,9−6,2 GHz), komunikasi downlink satelit X-Band (7,1−7,6 GHz), dan komunikasi Direct Broadcasting Satellite (DBS) (12,2−12,7 GHz). Dengan metode ini, berhasil diperoleh peningkatan lebar pita antena UWB dari 7,72 GHz menjadi sebesar 13,22 GHz, tanpa mengubah karakteristik pola radiasi antena. Penambahan tiga notch band juga berhasil diimplementasikan tanpa harus mengubah dimensi antena keseluruhan, yaitu sebesar 35,6 mm × 27,3 mm.

Analysis and Development of an Efficient Cross-Slot Loaded Compact Electromagnetic Band Gap Antenna

This paper is devoted to a novel Electromagnetic Band Gap (EBG) single-feed circularly polarized microstrip EBG antenna with compact size proposed for C-Band applications. The antenna structure will include eight slits introduced at the boundary and the corners in the radiating square patch with a cross-slot at the center. The provided study will effectively approve the various proposed structures and interest occupied by these types of antennas in the enhancement of output parameters (gain, directivity, radiation efficiency, and bandwidth) without much affecting the operating bandwidth at C-band. At first, the concept and the realization of a directive and circularly polarized antenna using an electromagnetic band gap material whose circular polarization is generated by the structure itself is discussed. The analysis and simulation results are presented for an antenna operating at 6.1 GHz using computer Simulation Technologies (CST). Furthermore, the new compact circular polarized EBG antenna, compared to experimental results, will confirm the pre-studied goal of these kinds of antennas such as radiation efficiency, polarization purity, radiation efficiency, high directivity, and gain.