The paper deals with reverberation chambers for over-the-air (OTA) testing of wireless devices use in multipath. We present a formulation the S-parameters chamber terms free space antennas, and channel matrix way this is known from propagation literature. Thereby physical relations between real-life multipath environments are more easily explained. Thereafter we to determine uncertainty by which efficiency-related quantities can be measured chamber. final expression shows that predominantly...

This paper proposes a dual-band eight-antenna array for multiple-input and multiple-output (MIMO) applications in 5G mobile terminals. The designed MIMO antenna comprises eight L-shaped slot antennas based on stepped impedance resonators (SIRs). required dual-resonance can be obtained by adjusting the ratio of SIR, good matching ensured each element tuning position microstrip feed line. experimental results show that measured return loss higher than 10 dB inter-element isolation greater 11.2...

This letter finds the relation between different parameters that characterize reverberation chamber as a channel emulator for over-the-air (OTA) testing of wireless devices and components. It is shown experimentally first time coherence bandwidth proportional to average mode chamber. Both increase when loaded with absorbing objects, thereby, can be controlled emulate many real-life environments. The relationship RMS delay spread are found from measured response equal theoretical isotropic...

This paper introduces a planar switchable 3-D-coverage phased array for 28-GHz mobile terminal applications. In order to realize beam scan with simple array, chassis surface waves are efficiently excited and controlled by three identical slot subarrays. Three subarrays switch their beams distinct regions. Each subarray works as steer the within each region. Large coverage efficiency is achieved. (e.g., 80% of space sphere has realized gain over 8 dBi.) The proposed antenna covers bandwidth 2...

A concept of decoupling ground is introduced in this paper to enhance the isolation massive MIMO antenna arrays. For an array, mutual coupling between array elements can be achieved by free-space and currents flowing on plane shared elements. The improved adjusting shape under each element make from free space out phase. In way, low realized. As first example, a single-polarization linear with eight designed, simulated, measured verify as well simulation accuracy. measurements align very...

Previous studies on orbital angular momentum (OAM) communication mainly considered line-of-sight environments. In this letter, however, it is found that OAM with high-order modulation can be achieved in highly reverberant environments by combining the multiplexing a spatial equalizer. The exhibits comparable performance of conventional multiple-input multiple-output (MIMO) system.

This paper presents a compact dual-band and dual-polarized millimeter-wave patch antenna array with satisfactory performance on element mutual coupling beam scanning capabilities. Using capacitive feed technique stacked configuration extra parasitic strips, the proposed is able to achieve wide operating bandwidth in both low- high-bands. In order reduce array's footprint, enhance bands, spacing shrunk less than 0.36 wavelength at 26 GHz. To improve isolation between elements due their small...

A compact structure with slot splitting meandered lines defected ground is proposed to reduce the mutual coupling between two microstrip antennas a center-to-center distance of 0.38λ. The line symmetrically etched on antennas. optimized and explained by common/differential mode theory. For experimental verification, fabricated measured. Simulation measurement results excellent agreement show that can be reduced significantly using structure. In addition, significant improvement achieved in...

A compact phased array with extended beam steering characteristics for the millimeter-waveband of fifth-generation (5G) applications is presented in this communication. An E-shaped patch antenna placed on an electromagnetic bandgap ground (EBGG) operating bandwidth 24.2–27.5 GHz used as basic building block eight-element linear array. The utilizes both in-phase reflection characteristic broad element radiation pattern and mutual coupling reduction limited inter-element spacing proposed...

Dielectric resonator magnetoelectric dipole (DRMED) arrays with enhanced isolation, reduced cross-polarization, and backward radiation are proposed for base station (BS) applications. The antenna comprises an elevated dielectric (DRA) on a small metal plate above sizeable common ground plane. DRA is designed in its TE <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">δ11</inf> mode, acting like magnetic dipole. surface current excited by the...

We present a simple theoretical model for the throughput data rate of wireless LTE device including improvements due to diversity in frequency (OFDM) and spatial domains (MIMO) under selective fading. The is based on defining an ideal threshold receiver line-of-sight (LOS) case, corresponding reception with advanced error-correcting codes. agreement measurements reverberation chamber commercial 1 × 2 SIMO both regarding MIMO array gains, it can therefore be used complement measured results...

A compact dual-polarized antenna with total dimensions of 31 × 14 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> is proposed for the fifth-generation base stations at 3.5 GHz. The consists two orthogonal bow-tie dipoles. bandwidth enhanced using eight parasitic strips along dipole patches, U-shaped slots around feeding positions, and dielectric cavity, which brings resonant frequencies closer to each other. isolation between dual...

This paper presents simple throughput models for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems with hybrid automatic repeat request (HARQ). In particular, we consider the long term evolution (LTE) systems. Antenna correlations and power imbalances are implicitly included in models. order to explicitly characterize antenna effects on throughput, resort spatial (SM) efficiency. The SM efficiencies of a MIMO zero forcing (ZF), minimum mean square...

In this letter, an active metasurface for vortex beam generation is proposed. This can transform the incident plane wave into beams carrying orbital angular momentum of three different orders. composed array varactor diodes loaded unit cells. The transmission phase each cell be fully controlled by capacitance diodes. Different modes separately generated simply changing distribution on aperture. properties proposed are demonstrated simulation and measurement results, which have a good...

In this paper, a ε-negative metasurface superstrate is proposed for mutual coupling reduction of large antenna arrays. Unlike the previous decoupling works that are mostly confined to two-ports antennas, can be extended massive multiple-input multiple-output (MIMO) systems. A 4 × array used as an example illustrate performance metasurface. With metasurface, worst improved by 8 dB over operation bandwidth with maximum 25 dB. Moreover, also help restore radiation patterns, bring down active...

Baffles loaded by split-ring resonator (SRR) are proposed to reduce the mutual coupling for ±45° dual-polarized multiple-input-multiple-output (MIMO) antenna. Each baffle consists of two rectangular SRR printed on one side a 1 mm FR4 substrate. The final decoupling structure contains four baffles forming barrier wall that reduces over 5G band 3.4-3.8 GHz. Dual-polarized cross-dipole array with loading is simulated and measured demonstrate their effectiveness in reduction. results show can be...

The reverberation chamber (RC) has traditionally been used for electromagnetic compatibility tests. About two decade ago, it found application in various over-the-air (OTA) tests of antennas and wireless devices. This paper gives an overview nearly decades research on the RC-based OTA tests, ranging from antenna measurements characterizations to both terminals base stations. Apart advantages some important issues are identified.

The holographic multiple-input-multiple-output (MIMO) communications refer to the MIMO systems built with ultra-dense antenna arrays, whose channel models and potential applications have attracted increasing attentions recently. When spacing between adjacent array elements is larger than half wavelength, effect of mutual coupling can generally be neglected in current designs. However, communications, influence strong on characteristics inevitable, resulting distorted radiation patterns low...

Flow path is regarded as a greatly crucial transmission component in the fluid power system, whose flow characteristic heavily dependent on shape profile of path. A modified that functions simplified check valve designed to suppress transition backflow this article. The topology design was implemented by mean variable density method with objective minimized viscous dissipation energy COMSOL software. ratio pressure drop between reverse and forward (names diodicity) applied verify feasibility...