A Novel CPW-Fed Planar Monopole Antenna With Broadband Circularly Polarization

Abstract

A novel CPW-fed planar printed monopole antenna with broadband circular polarization (CP) characteristic is presented. The proposed antenna consists of a copper coin-shaped patch (CCSP) and an asymmetrical ground plane. To achieve a broadband CP wave, a vertical stub is added to the CCSP to produce orthogonal surface currents for right-hand circular polarization (RHCP). The design of the CCSP greatly increases the impedance bandwidth (IBW) of 89.2% which can cover the whole CP bandwidth of 71% completely. The measured results show that the proposed antenna has not only a broad 3-dB AR bandwidth (ARBW) of 71% (3900 MHz, 3.1-7 GHz) with respect to the CP center frequency 5.8 GHz, but also a wide 10-dB return loss bandwidth of 89.2% (5040 MHz, 2.16-7.2 GHz) centered at 5.65 GHz.

A compact broadband coplanar waveguide fed circularly polarized printed monopole antenna with asymmetric modified ground plane

“…The proposed antenna can provide bidirectional radiation, LHCP wave at the +z direction, and RHCP on the opposite antenna side with reasonable agreement between simulated and measured CP radiation pattern, while the measured radiation pattern is a slightly distorted attributed to use SMA connector with relatively large ground, beside the welded joint of SMA connector and fabrication tolerance also contribute to a slight pattern distortion. The comparison of the proposed antenna and recently reported antennas [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] in Table 1 shows that the proposed antenna provides broader IBW and ARBW and has the smallest relative size of 0.47λ o × 0.47λ o . It also provides symmetric radiation patterns.…”

“…Printed monopole antennas are thus the ideal choice for designing compact antennas with a broadband CP property. Several printed CP monopole antennas with different shapes and techniques were proposed in References . Examples include using a branched microstrip feed line with parallel slots, C‐shaped slot antenna, moon‐shaped patch and moon‐shaped ground plane, and parasitic patches with an L‐shaped slot .…”

“…A simple straight monopole obtained a broad IBW and ARBW by loading two open‐loop parasitic strips on both antenna sides . Broad IBW and ARBW were achieved by using an inverted L‐shaped strip with an asymmetric ground plane and by using a C‐shaped radiator and two triangular stubs placed on the ground plane, or using coin‐shaped radiator with asymmetric CPW‐fed ground plane . These previously developed CP antennas achieve a broad IBW and ARBW, but band extensions are performed by extending the antenna dimensions, thereby limiting the use of these antennas in modern compact communication systems.…”

“…19 Broad IBW and ARBW were achieved 20 by using an inverted L-shaped strip with an asymmetric ground plane and 21 by using a C-shaped radiator and two triangular stubs placed on the ground plane, or using coin-shaped radiator with asymmetric CPW-fed ground plane. 22 These previously developed CP antennas achieve a broad IBW and ARBW, but band extensions are performed by extending the antenna dimensions, thereby limiting the use of these antennas in modern compact communication systems. Achieving broad IBW and ARBW to cover most wireless communication frequencies without requiring antenna size enlargement remains a challenge for antenna designers.…”

Truncated Circular Microstrip Ultra Wideband Antenna Exhibiting Wideband Circular Polarization

“…CPW-fed planar antennas with various methods viz. L-shaped slot and strip [5], horizontal slit and inverted L-strip on the ground [6], L-shaped slot and partial ground plane with different heights on either side of the feed line [7] are adopted to improve the ARBW. A CPW-fed planar antenna having quadrilateral shaped radiating copper and an asymmetric ground plane is illustrated in [8].…”