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A cost-effective and accurate method for predicting over-the-air (OTA) data throughput of multiple-input and multiple-output (MIMO) wireless devices in the antenna design stage is proposed. The method incorporates passive characteristics of MIMO antennas, realistic channel model, and conductive measurement results in a computer simulation framework. With extracted relation between received power and signal-to-noise ratio (SNR) of a wireless device at antenna ports by a conductive test and measured passive characteristics of MIMO antennas, OTA throughput versus received power in a realistic channel model is obtained by the Monte Carlo simulation of Shannon’s law. The unique features of this method include: no channel emulator equipment is required; a wide variety of precoding schemes can be applied; passive characteristics of antennas are fully incorporated; and frequency-selective fading channel can be adopted. The method has been intensively validated by comparing the calculated OTA throughputs with those measured by a multiprobe anechoic chamber method under spatial channel model extension (SCME) in three aspects: spatial correlation, radiation efficiency, and mutual coupling, showing as low as 0.2–0.3 dB discrepancy in power level in most cases. The method can be used to evaluate a MIMO array antenna design of a wireless device with respect to OTA performance. [ABSTRACT FROM AUTHOR]

In this article, H-plane cross-polarization (X-pol) radiation of probe-fed air-filled patch antennas is substantially suppressed by introducing two or more floating metal cylinders underneath the patch, respectively. The X-pol is canceled by the radiation of induced currents on metal cylinders. The working principle of the new X-pol suppressed patch (XSP) antenna is revealed by an approximate model. The X-pol level of a typical XSP antenna can be suppressed to lower than −49 and −37 dB theoretically and experimentally for $| \theta |\le 60^{\circ }$. Two $1\times $ 8-element arrays constructed by XSP antennas and conventional patch antennas are prototyped and measured at scanning beam angles of $\theta = 0^{\circ }$ , −40°, and −65°. The measured co-polarization (co-pol) gain of the XSP antenna array is 0.7 and 0.9 dB larger than that of the conventional patch array at $\theta = -40^{\circ }$ and −65°, respectively. Besides, the beam scanning angle with −30 dB X-pol level of the XSP antenna array can be as wide as $| \theta |\le 40^{\circ }$ , while that of the conventional patch array is about $| \theta |\le 12^{\circ }$. A wide-band dual-polarized XSP antenna is also presented. The measured maximum H-plane X-pol level can be lower than −29 dB within 8.7% fractional bandwidth. [ABSTRACT FROM AUTHOR]

A new wideband ±45° dual-polarized metal loop dielectric resonator magnetoelectric antenna is proposed in this communication. The antenna consists of two orthogonal dielectric bars that support two orthogonal electric dipoles and two cross interlaced metal semi-loops that are equivalent to two orthogonal magnetic dipoles above the ground. With a legitimate combination of the electric and magnetic dipoles, a unidirectional radiation with low backward radiation and equal E-plane and H-plane radiation patterns can be achieved. The antenna can be made of a monolithic dielectric block with simple installation. To validate the new antenna configuration, a prototype is designed, manufactured, and measured. The prototype antenna using ceramic with the electrical size of $0.33\lambda _{o} \times 0.33\lambda _{o} \times 0.21\lambda _{o}$ demonstrates that an impedance bandwidth of 11.4% ($\vert S_{11}\vert < -15$ dB) in the 3.5 GHz frequency band can be achieved with the measured forward/backward ratio of better than 22 dB. The proposed antenna is suitable as antenna element for massive-MIMO array antennas, where a large number of antenna elements need to be installed in a compact space. [ABSTRACT FROM AUTHOR]

An integrated low-temperature co-fired ceramic (LTCC) coupled resonator decoupling network (CRDN) for two coupled antennas is proposed in this paper. By virtue of LTCC technology, a second-order CRDN is realized by two tightly coupled lumped-element resonators in a volume of \3.2\times \2.5\times \1.2\ \mm^3. Theoretical analysis has revealed that a wide range of mutual admittance of a CRDN can be realized by choosing appropriate I/O coupling elements while the coupled resonators can be consolidated in an LTCC device. This “one-fit-all” feature allows for decoupling a wide range of coupled antennas with different form factors for a given frequency band. To prove the concept, two LTCC CRDNs for decoupling different forms of antennas working in the 2.45-GHz band are designed, fabricated, and tested. Measurement results have demonstrated that significant improvement in isolation can be achieved within a wide operating frequency range in all cases. The presented design theory and circuit topology are general and can be applied to both symmetric and asymmetric two-element antenna arrays. [ABSTRACT FROM PUBLISHER]

A new decoupling scheme called dual-band coupled resonator decoupling network (CRDN) is presented. By properly designing the coupling coefficients between two pairs of coupled resonators, the network can effectively reduce the mutual couplings between two coupled dual-band antennas in two bands simultaneously. The new scheme is proved by a practical microstrip version of the device for two dual-band antennas working at 2.4 and 5.2 GHz frequency bands. A compact planar dual-band CRDN consisting of a pair of dual-band open-loop square ring resonators is proposed. The measured scattering parameters of two coupled antennas with and without the dual-band CRDN in free space (FS) and with hand phantom demonstrate that the isolation between the two antennas in both the low and high bands can be improved from 8 to 10 dB, respectively, to below 20 dB while maintaining a good matching performance. The total efficiency and envelop correlation coefficient for the decoupled antennas show a significant improvement as compared to the coupled antenna case. The proposed dual-band CRDN scheme is easy to be implemented in an integrated device, and is very attractive for practical multiple input and multiple output (MIMO) applications. [ABSTRACT FROM PUBLISHER]

A wideband planar dielectric rod antenna with substrate integrated non-radiative dielectric (SINRD) waveguide feed, is presented in this communication for W-band and up-millimeter-wave applications. The antenna and its feeding structure are integrated into a single layer substrate, which decreases the fabrication cost and integration complexity. Simulated and measured results show that the antenna has a wide bandwidth. Due to the structure of the SINRD guide which is shielded on top and bottom of the substrate, the proposed antenna is suitable for multilayer structure techniques such as LTCC or on-chip antenna. This antenna presents numerous features such as broad bandwidth, relatively high and stable gain, use of high dielectric constant substrate, and substrate-oriented end-fire radiation. The proposed antenna is suitable for gigabyte chip-to-chip communications. Measured bandwidth of the antenna is 10 GHz (93–103 GHz) while a relatively flat gain of 9.5 \pm 1~dB is obtained over the bandwidth of interest. [ABSTRACT FROM PUBLISHER]

A class of three-dimensional planar arrays in substrate integrated waveguide (SIW) technology is proposed, designed and demonstrated with 8 \times 16 elements at 35 GHz for millimeter-wave imaging radar system applications. Endfire element is generally chosen to ensure initial high gain and broadband characteristics for the array. Fermi-TSA (tapered slot antenna) structure is used as element to reduce the beamwidth. Corrugation is introduced to reduce the resulting antenna physical width without degradation of performance. The achieved measured gain in our demonstration is about 18.4 dBi. A taper shaped air gap in the center is created to reduce the coupling between two adjacent elements. An SIW H-to-E-plane vertical interconnect is proposed in this three-dimensional architecture and optimized to connect eight 1 \times 16 planar array sheets to the 1 \times 8 final network. The overall architecture is exclusively fabricated by the conventional PCB process. Thus, the developed SIW feeder leads to a significant reduction in both weight and cost, compared to the metallic waveguide-based counterpart. A complete antenna structure is designed and fabricated. The planar array ensures a gain of 27 dBi with low SLL of 26 dB and beamwidth as narrow as 5.15 degrees in the E-plane and 6.20 degrees in the 45^\circ-plane. [ABSTRACT FROM PUBLISHER]