Design of a Windmill-Shaped Loop Antenna for Polarization Diversity

Designing an omnidirectional horizontally polarized circular patch antenna implementing unequal open‐circuited stubs

“…However, in urban and indoor wireless communication, horizontally polarized antennas are preferred over vertically polarized antennas due to their ability to mitigate signal degradation caused by severe multi‐fading loss 5 . Over the past few decades, three primary methods have been employed to implement horizontally polarized antennas: horizontal loop antennas, 6–18 array antennas, 19–23 and magnetic current configurations or cavity antennas 24–27 . In addition, the development of omnidirectional horizontally polarized (OHP) antennas has explored various other techniques, including the utilization of sequential horizontal open slots 28,29 …”

“…Larger loop antennas compromise omnidirectional radiation due to out‐of‐phase current, whereas small loop antennas have low radiation resistance and high input reactance 1 . The Alford loop antenna, in both its wire loop and printed configurations, offers an alternative solution with improved radiation resistance, horizontal polarization, and omnidirectionality, achieved through a square‐shaped λ‐length wire loop structure or by using Z‐shaped strips or a windmill‐shaped arch on opposing sides of a substrate, respectively 6–8 . However, a miniaturized circular loop antenna consists of multiple‐fold resonant dipole antennas, forming a circular loop antenna, which yields an OHP radiation pattern with poor efficiency and a narrow band 9 .…”

“…have been employed to implement horizontally polarized antennas: horizontal loop antennas, [6][7][8][9][10][11][12][13][14][15][16][17][18] array antennas, [19][20][21][22][23] and magnetic current configurations or cavity antennas. [24][25][26][27] In addition, the development of omnidirectional horizontally polarized (OHP) antennas has explored various other techniques, including the utilization of sequential horizontal open slots.…”

“…1 The Alford loop antenna, in both its wire loop and printed configurations, offers an alternative solution with improved radiation resistance, horizontal polarization, and omnidirectionality, achieved through a square-shaped λ-length wire loop structure or by using Z-shaped strips or a windmill-shaped arch on opposing sides of a substrate, respectively. [6][7][8] However, a miniaturized circular loop antenna consists of multiple-fold resonant dipole antennas, forming a circular loop antenna, which yields an OHP radiation pattern with poor efficiency and a narrow band. 9 To overcome these limitations, the dual-band 10 and wideband 11 OHP antennas have been enhanced by incorporating two or more arch-shaped strips on both sides of the substrate.…”