Broadband Circularly Polarized 2 × 2 Antenna Array with Sequentially Rotated Feed Network for C-Band Application

Abstract

In this paper, a unique broad-band circularly polarized antenna array with sequentially rotated feed-network for C-band applications is proposed. In order to, implement presented array element, a novel and miniaturized square slot antenna, with one pair of attached L-shaped and a T-shaped strips at ground surface, for decreasing cross polarization purity, is presented. Two L-shaped strips with different length are inserted at slot antenna's patch to enhance impedance matching. The symmetric coplanar waveguide is used for feeding the slot element. The antenna element obtains a 3 dB axial ratio bandwidth from 5.85 to 6.25 GHz. For further improving of radiation attributes, elements in 2 9 2 array are linked together by sequentially rotated feed to achieve wider axial ratio and impedance matching bandwidths. The main advantage of feed network is designed in a way that to have less coupling effect between elements. The axial ratio (AR) and impedance bandwidths of array is from 4.9 to 6.45 GHz (for AR \3 dB) and 4 to 8.1 GHz (for VSWR \2), respectively. Simulation and measurement results validated the proposed array design.

A Compact Array Antenna: Explicit Design for C and X Band Applications

“…Accordingly, gain requirement of real-case communication systems is satisfied. The recorded gain value is a bit smaller than the recorded values in [12][13][14][15][16][17]. It is worth noting that higher gains are obtained via larger array structures with limited impedance bandwidth and narrower AR.…”

“…3. As this table unveils, the array size in [12][13][14][15][16] is larger than the proposed SAA. This is while; 10-dB impedance bandwidth and 3-dB AR bandwidths are narrower which reveals a performance defect against the larger implementation space.…”

“…However, a suitable compromise could be established to reach to a welldressed design with anticipated functionalities. As well, comparison of radiation patterns in [12][13][14][15][16][17] reveals that suitable radiation patterns are obtained for communication systems applications in the aforementioned designs.…”

“…To this end, the established 2 × 2 structure is tailored against the recently published 2 × 2 designs [12][13][14][15][16][17]. The comparison is conducted in terms of 10-dB impedance bandwidth, 3-dB AR bandwidth, and the total size of the array antenna.…”

Circular polarization realization in array antennas by a modified sequential phase feeding mechanism of linearly polarized elements

“…Comparison of the proposed performance of the 2 × 2 array structure with some of the previous designs would be fruitful to shed light on the advantages of the present work. To this end, Table 3 provides the characteristics of some previously published designs in [23–28] and the proposed antenna. As the provided data imply, the proposed antenna is the smallest among the antennas in [23–27].…”