Mutual Coupling-Based Compact Wideband Circularly Polarized Antenna

Abstract

A small size and wideband circularly polarized antenna is introduced. The key innovation is that the antenna is based on four confined highly coupled microstrip patches fed by a composed right-left hand integrated feeding network. Mutual coupling is thus effectively used in a constructive way. It is shown that this idea results in an excellent combination of axial ratio (AR) bandwidth and small size. A prototype was built and measured proving the concept in practice. The impedance bandwidth is 110%, the AR bandwidth at broadside is more than 83%, and the-3 dB gain bandwidth (with respect to maximum gain) is 65%, with an overlap of 63% when considering all three at the same time. The antenna lateral size is as small as 0.52λ0×0.52λ0 where λ0 is the midband wavelength.

Metamaterial‐based, compact, wide beam‐width circularly polarized antenna for 5G indoor application

“…Although the multi-port CP antennas have a wide CP bandwidth, they usually need a large size and extra feeding network. 15,16 In practical application, the wide beam-width CP antenna can realize wide signal coverage and wide angle radiation, 17 so it is very suitable for indoor/urban wireless communication scenarios. To realize the wide beam-width operation, parasitic patch/extra reflector/thick substrate/dimension reduction were adopted.…”

“…The wideband crossed dipole CP antennas with high profiles are researched in References 13 and 14 and they are more suitable for outdoor base station applications. Although the multi‐port CP antennas have a wide CP bandwidth, they usually need a large size and extra feeding network 15,16 . In practical application, the wide beam‐width CP antenna can realize wide signal coverage and wide angle radiation, 17 so it is very suitable for indoor/urban wireless communication scenarios.…”

Meta‐surface loading broadband and high‐aperture efficiency dual circularly polarized patch antenna

“…Compared with linearly polarized (LP) antennas, circularly polarized (CP) antennas have special advantages in overcoming polarization mismatch and multipath effect caused by buildings or other obstacles. CP antennas have been deeply investigated 1‐8 and widely used in many modern wireless transmission systems, such as satellite communications, global position system (GPS), point‐to‐point data transfer, millimeter‐wave receiving, ultra‐wideband (UWB) communications, and radio frequency identification (RFID), etc. In particular, antennas, which have dual‐CP operation can significantly increase the channel capacity and are urgently needed 9 …”

A low profile metasurface‐based circularly polarized antenna

“…However, most of the feed network (FN) uses Wilkinson power divider. [3][4][5][6][7] The metasurface has been added to improve antenna performance. The multilayer wideband antenna uses complex stacking structure to improve the gain, 8 so it does not take the advantage of the low profile.…”