Compact single‐feed circularly polarized aperture‐coupled stack antenna with minkowski‐island‐based fractal patch

Abstract

The authors propose a compact single‐feed stack antenna consisting of a Minkowski‐island‐based (MIB) fractal patch with perturbation, an aperture‐coupled structure, and a straight‐strip feed line for circular polarization (CP) and unidirectional radiation applications. The MIB fractal configuration with second‐order iteration is embedded in the patch for miniaturization. The size reduction of 39.1% is achieved in contrast to the typical patch antenna. This fractal structure applies both dual‐mode and orthogonal mode effects simultaneously in the square patch to present bandwidth (BW) and CP characteristics. The stack antenna presents the desired axial ratio (AR) bands of 2.44 GHz with 3‐dB BW = 30 MHz (1.2%). The CP is demonstrated with AR spectrum, orthogonal modes distributions, and phase difference. The proposed antenna is successfully simulated and measured with frequency responses, radiation patterns, and current distributions. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2278–2283, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27090

Single-feed wideband circularly polarized patch antenna using dual mode defected ground waveguide coupling structure

“…Accordingly, the microstrip‐slot coupling structure can provide more degrees of freedom in the feed design. Many antennas excited through microstrip‐slot coupling structure have been reported . The feed methods using microstrip‐slot coupling structure to achieve CP patch antennas, which can be classified into dual‐ and single‐feed solutions.…”

“…Single‐feed has drawn much attention in past decades because of its simple structure and easy to fabrication . In Reference , a cross slot of unequal slot lengths is used as electromagnetic energy coupling structure from the microstrip feed line to patch and the CP radiation is easily obtained.…”

“…By only adjusting the perturbation in the square loop radiator, both dual mode and orthogonal mode effects exist simultaneously in the square loop radiator to achieve CP antenna. In References , a Minkowski‐island‐based (MIB) fractal square patch with a perturbation antenna coupled by a single slot is proposed. By the MIB fractal and loading perturbation in the corner of the square patch, the dual mode is excited in the asymmetrical square patch and then wideband frequency responses and CP characteristics are presented.…”

Dual-band circularly polarized aperture-coupled stack antenna with fractal patch for WLAN and WiMAX applications

“…Recently, the CPW‐fed square slot antenna with 2.34–6.44 GHz wide‐band and CP was proposed for WLAN and WiMAX applications . The CP aperture‐coupled stack antenna with Minkowski island‐based fractal patch was developed for WLAN systems . Thus, an aperture‐coupled stack antenna designed with fractal geometry is a candidate for WLAN and WiMAX multiband and CP operation for applications.…”

“…Based on the study of the Minkowski geometry , CP characteristics and multiband responses , an alternative design of the aperture‐coupled stack antenna with a complementary Minkowski‐island‐based (MIB) fractal geometry for 3.56/5.28 GHz dual‐band CP applications is presented in this paper. By the perturbation and MIB fractal, this dual‐mode existed in the asymmetrical square patch to present wide‐band and CP characteristics.…”