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

A compact T-shaped feed structure (IFS) 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 IFS 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.National Natural Science Foundation [61571289, 61571298, 61701303]; Natural Science Foundation of Shanghai [17ZR1414300]; Shanghai Pujiang Program [17PJ1404100]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Designs and Performance Characteristics of Coated Nanotoroid Antennas

The electromagnetic properties of a toroidal coated nanoparticle (T-CNP) antenna with an active core (doped with rare earth erbium Er3+ ions) are investigated. It is demonstrated that the active T-CNP acts as a strong dipole radiator at its resonance frequency when it is excited by a plane wave or an electric Hertzian dipole (EHD) radiating element. It is shown that in comparison to being a passive structure, the plane wave scattering cross section of the T-CNP can be increased by nearly 108 dBsm at its resonance frequency when it is active. Moreover, it is further demonstrated that the maximum peak of the power radiated by an EHD element in the presence of a properly designed active T-CNP is more than 120 dB over its value when radiating in free space; that is, its Purcell factor is 1012

Even- and odd-mode analysis of thick and wide transverse slot in waveguides based on a variational method

Based on a new variational method, an even- and odd-mode analysis of transverse coupling slot between waveguides is presented. The proposed method is capable of dealing with slots of finite wall thickness. It uses multiple incident waves with symmetry to simplify the field distribution in the vicinity of the slot, enabling the adoption of one-expansion-term trial functions with sufficient accuracy, even in the instance of wide slots. Analytical solutions are provided, and the calculated results demonstrate excellent agreement with those of numerical simulation. The computation time with the new formulation is, however, significantly shorter. © 1963-2012 IEEE

A surface plasmon polariton inspired patch antenna

© 2017 IEEE. A patch antenna augmented with a magnetic surface plasmon polariton (SPP) spiral is proposed. It is fed by a small loop antenna. The final prototype of the optimized antenna has an overall size of 80 mm × 80 mm × 1 mm. Simulation results show that it has three working frequency bands; the -10 dB impedance bandwidth of each is: 1.99-2.52 GHz, 3.22-4.26 GHz and 4.71-5.16 GHz. These three working frequency bands all have field distributions characteristic of a scatterer with an excited, localized SPP mode. The peak gain achieved by this antenna is 6.5 dB