A Compact Wideband Circularly Polarized Planar Monopole Antenna With Axial Ratio Bandwidth Entirely Encompassing the Antenna Bandwidth

Abstract

The antenna presented in this study is a compact wideband monopole with wideband circular polarization that can be used across the whole antenna bandwidth. A rectangular C-shaped patch is partially covered by a ground plane in the proposed planar monopole antenna. Inserting a rectangular stub to the ground plane, etching a slit at the antenna patch, and adding a semicircular stub at the top of the antenna feed line increase the antenna impedance bandwidth (BW) and axial ratio bandwidth (ARBW). An FR4 substrate with overall dimensions of 25 mm×25 mm×1.6 mm is used to create the antenna. The antenna's observed impedance BW is 70% (4.55 GHz in the 4.3-8.85 GHz band), while the measured broadside ARBW is improved to a value of 82.2 percent (5.3 GHz along the range 3.8-9.1 GHz). The impedance BW is perfectly covered by the ARBW; hence the antenna can be considered circularly polarized throughout its operational spectrum. Within the antenna BW, the measured gain is greater than 1.5 dB.

A Compact Broadband Circularly Polarized Wide-Slot Antenna With Axial Ratio Bandwidth Encompassing LTE 42 and LTE 43 Standards of 5G Mid-Band

“…The CP antenna can be designed as a multiband antenna [3][4][5], in which the 3dB ARBW partially covers the intended bands. On the other hand, there is the choice of providing a wideband (or ultra-wideband) CP [6][7][8][9] with -10dB impedance bandwidth (BW) and 3dB ARBW that are not specified for certain applications. The broadband CP antennas deal with providing ARBW that occupies a certain application and impedance BW that has a minimized residual effect on the adjacent frequency bands.…”

A broad axial ratio bandwidth and wide angle coverage circularly polarized monopole antenna for wireless communication

“…To improve ARBW, several techniques are adopted and reported in Refs. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] One simple C-shaped broadband CPMA is realized and its ARBW is optimized by introducing a rectangular open loop strip and stub in ground plane. 2 In Midya et al 3 another broad axial ratio bandwidth CPMA was implemented by introducing G-shaped parasitic strip (PS) with a C-shaped radiator.…”

“…In addition, two compact CP antennas are implemented using stubs and slits and synthesis technique, respectively. 19,20 In addition, numerous techniques are also being applied to improve gain by applying metasurface, 21 antenna array with sequential phase feed structure [22][23][24] and metallic reflectors with defected side walls. 25 Nevertheless, ARBW and impedance bandwidth (IBW) plays an important role to cover maximum range of spectrum for different applications.…”

“…The major problem with CPMA is less axial ratio bandwidth (ARBW). To improve ARBW, several techniques are adopted and reported in Refs 2–20 . One simple C‐shaped broadband CPMA is realized and its ARBW is optimized by introducing a rectangular open loop strip and stub in ground plane 2 .…”

“…In Sharma et al, 18 characteristic mode analysis is done for verification of CP mode instead of conventional method. In addition, two compact CP antennas are implemented using stubs and slits and synthesis technique, respectively 19,20 . In addition, numerous techniques are also being applied to improve gain by applying metasurface, 21 antenna array with sequential phase feed structure 22–24 and metallic reflectors with defected side walls 25 .…”