Broadband Circularly Polarized Slot Antenna Array Fed by Asymmetric CPW for C-Band Applications

ABSTRACT

In this manuscript, a new design of broadband circularly polarized (CP) array antenna is presented. A 2 × 2 planar array antenna is accomplished using the proposed CP diamond-shaped slot element with an L-shaped patch. The feed network employs a 180-degree rat-race hybrid coupler to realize a −3 dB power split, equal in magnitude, 180-degree difference in phase. Two branch-line couplers then divide the signal energy into two paths and give the signal to each of the output branches with the same amplitude, but phase-shifted by 90 degrees, wherein the relative phases at four feed points are 0, 90, 180, and 270 degrees. The final dimensions of the 2 × 2 element array are 112 × 97 × 0.8 mm³. The simulated result shows that the impedance bandwidth for a voltage standing wave ratio (VSWR) < 2 is around 39.86% (4.78–7.16 GHz), and the 3-dB simulated AR (axial ratio) bandwidth is about 24.2% (4.83–6.16 GHz), and the antenna has a peak gain of 7.69 dBi over the bandwidth.

KEYWORDS:

• Array antenna
• Broadband antenna
• C-band
• circular polarization
• CPW-fed
• Rate-race coupler

ACKNOWLEDGEMENT

The authors would like to thank the Department of Electrical Engineering, Urmia Branch, Islamic Azad University, Urmia, Iran.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Notes on contributors

Farzad Zandikiya

Farzad Zandikiya was born on 22 June 1989 in Urmia, Iran. He received his MS degree in 2016 from the Department of Electrical Engineering, Urmia Branch, Islamic Azad University, Urmia, Iran. His research includes antenna design and microwave instrumentation and measurement.

E-mail: [email protected]

Loghman Asadpor

Loghman Asadpor was born on 8 August 1984 in Urmia, Iran. He received his MS degree in 2010 and PhD degree in 2015 from the Department of Electrical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. He is already employed as an assistant professor in the Department of Electrical Engineering, Urmia Branch, Islamic Azad University, Urmia, Iran. His research includes antenna design and microwave instrumentation and measurement.