Dual CP Polarization Diversity and Space Diversity Antennas Enabled by a Compact T-Shaped Feed Structure

Abstract

A compact T-shaped feed structure (TFS) is reported that enables the realization of two types of diversity antennas: a polarization diversity antenna (PDA) and a spatial diversity antenna (SDA). Both systems have a high potential for mobile wireless communication applications. The TFS includes four ports and two independent coaxial channels with effective isolation between them all. The PDA is a dual CP omnidirectional antenna. Its optimized prototype achieves measured impedance bandwidths of 16.4% and 15.28% in its LHCP and RHCP states, respectively, and realized gains in both between 4.8 and 6.46 dBic. The inner thin coaxial cable (ITCC) of the TFS directly drives its LHCP subsystem, facilitating its improved omnidirectional performance. This ITCC is also used to directly feed the SDA's low-profile directional planar equiangular spiral antenna and its side port drives its omnidirectional RHCP antenna. Good hemispherical coverage is realized with a measured common impedance bandwidth larger than 14.35% with more than 40-dB isolation between its two ports. The corresponding measured realized gain of the SDA is between 4 and 7.8 dBic. The measured results for both optimized prototypes confirm their simulated performance characteristics.

A Modified SWB Hexagonal Fractal Spatial Diversity Antenna With High Isolation Using Meander Line Approach

“…They also enhance the reliability and overall average received power by adding more transmitting/receiving channels [2], [3]. However, the spatial diversity antenna is preferred over pattern and polarization diversities in wireless communication applications due to its distinct benefits such as reducing the requirement of additional spectrum [4], providing high-quality communication services, and enabling flexible coverage area [5]. MIMO systems with spatial diversity techniques allow modern wireless devices not only to extend the spectral efficiency for both communication terminals but also accomplish high-quality services under hostile scattering circumstances [6].…”

A CPW‐fed compact square slot antenna with wideband circularly polarized for C‐band application

“…Among them, single‐fed CP antennas are commonly used for their simple structure, ease of manufacture, and low cost. Most of these antennas use the coplanar waveguide (CPW) feed, 8,9,17 while some of them use the probe feeding technique 19 . However, the CPW‐fed structure is a good candidate for a vast bandwidth with a low profile.…”