A Dual-Frequency Omnidirectional Antenna for Polarization Diversity of MIMO and Wireless Communication Applications

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 …”

“…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.…”

“…[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. In the case of ultrahigh frequency applications, segmented antennas have been designed, utilizing multiple metal sections and lumped components, to increase the electrical size of the loop and improve the OHP radiation pattern.…”

An S‐band wide beam miniaturized omnidirectional circularly polarized antenna

“…Omnidirectional antennas are required for maximum signal coverage in many wireless devices or systems, including cellphone base stations, WLAN routers, vehicle-mounted communication systems and synthetic aperture imaging radars (SAR), and so on. [1][2][3][4] Recently, circular polarized (CP) omnidirectional antennas have received more and more attention. Compared with LP antennas, CP antennas have many advantages.…”

Tunable reflective tri-band polarization converter based on graphene composite metasurface

“…In the contemporary era, the proficient modulation of electromagnetic wave polarization has garnered significant attention as a captivating research domain due to its extensive utilization in wireless communication 1 and radar and satellite detection 2 . The critical facet of polarization manipulation, i.e., polarization conversion, used to relied on employing birefringent or dichroic crystals 3 , 4 for its attainment.…”