Showing papers on "Antenna array published in 2013"

See through walls with WiFi

Abstract: Wi-Fi signals are typically information carriers between a transmitter and a receiver. In this paper, we show that Wi-Fi can also extend our senses, enabling us to see moving objects through walls and behind closed doors. In particular, we can use such signals to identify the number of people in a closed room and their relative locations. We can also identify simple gestures made behind a wall, and combine a sequence of gestures to communicate messages to a wireless receiver without carrying any transmitting device. The paper introduces two main innovations. First, it shows how one can use MIMO interference nulling to eliminate reflections off static objects and focus the receiver on a moving target. Second, it shows how one can track a human by treating the motion of a human body as an antenna array and tracking the resulting RF beam. We demonstrate the validity of our design by building it into USRP software radios and testing it in office buildings.

Broad electrical tuning of graphene-loaded plasmonic antennas.

Abstract: Plasmonic antennas enable the conversion of light from free space into subwavelength volumes and vice versa, which facilitates the manipulation of light at the nanoscale. Dynamic control of the properties of antennas is desirable for many applications, including biochemical sensors, reconfigurable meta-surfaces and compact optoelectronic devices. The combination of metallic structures and graphene, which has gate-voltage dependent optical properties, is emerging as a possible platform for electrically controlled plasmonic devices. In this paper, we demonstrate in situ control of antennas using graphene as an electrically tunable load in the nanoscale antenna gap. In our experiments, we demonstrate electrical tuning of graphene-loaded antennas over a broad wavelength range of 650 nm (∼140 cm −1 , ∼10% of the resonance frequency) in the mid-infrared (MIR) region. We propose an equivalent circuit model to quantitatively analyze the tuning behavior of graphene-loaded antenna pairs and derive an analytical expression for the tuning range of resonant wavelength. In a separate experiment, we used doubly resonant antenna arrays to achieve MIR optical intensity modulation with maximum modulation depth of more than 30% and bandwidth of 600 nm (∼100 cm −1 , 8% of the resonance frequency). This study shows that combining graphene with metallic nanostructures provides a route to electrically tunable optical and optoelectronic devices.

A Dual-Band Rectenna Using Broadband Yagi Antenna Array for Ambient RF Power Harvesting

Abstract: This letter presents a dual-band rectenna that can harvest ambient RF power of GSM-1800 and UMTS-2100 bands efficiently. The novel rectenna is based on a broadband 1 × 4 quasi-Yagi antenna array with bandwidth from 1.8 to 2.2 GHz and high gains of 10.9 and 13.3 dBi at 1.85 and 2.15 GHz, respectively. Also, a dual-band rectifier that can sufficiently enhance the RF-to-dc power conversion efficiency (PCE) at ambient RF power level is designed for the rectenna. Measurement results show that a PCE of 40% and an output dc voltage of 224 mV have been achieved over a 5-k Ω resistor when the dual-tone input power density is 455 μW/m 2. Additionally, output dc voltage varying between 300-400 mV can be obtained by collecting the relatively low ambient RF power.

The Multicell Multiuser MIMO Uplink with Very Large Antenna Arrays and a Finite-Dimensional Channel

Abstract: We consider multicell multiuser MIMO systems with a very large number of antennas at the base station (BS). We assume that the channel is estimated by using uplink training. We further consider a physical channel model where the angular domain is separated into a finite number of distinct directions. We analyze the so-called pilot contamination effect discovered in previous work, and show that this effect persists under the finite-dimensional channel model that we consider. In particular, we consider a uniform array at the BS. For this scenario, we show that when the number of BS antennas goes to infinity, the system performance under a finite-dimensional channel model with P angular bins is the same as the performance under an uncorrelated channel model with P antennas. We further derive a lower bound on the achievable rate of uplink data transmission with a linear detector at the BS. We then specialize this lower bound to the cases of maximum-ratio combining (MRC) and zero-forcing (ZF) receivers, for a finite and an infinite number of BS antennas. Numerical results corroborate our analysis and show a comparison between the performances of MRC and ZF in terms of sum-rate.

Frequency Diverse MIMO Techniques for Radar

Abstract: It has been shown over several decades of radar research that the exploitation of diversity in a number of domains (space, frequency, time, polarization, and, recently, waveform) can provide increased agility, flexibility, robustness, and capabilities to the radar system. However this is often achieved either through efforts in system design, increased hardware complexity, or by employing additional resources. A conventional antenna array is considered with the intention of introducing, not major, but minor mismatches, in particular in the carrier frequencies and, eventually in the codes at the element level. The starting point of this analysis is the frequency diverse array (FDA), which has been demonstrated to generate a range-angle pattern. Through a reconsideration of the organization of the array, which we have termed the wavelength array (WA), a new pattern, "orthogonal" to that of the standard phased array, can be achieved. The bistatic combination of a WA and a receiver leads to the frequency diverse bistatic system (FDBS), which can be a significant application of this concept. In a second stage the analysis focuses on the effects of introducing waveform diversity in such a system. In particular, if the elements of an electronically steered array (ESA) simultaneously transmit a number of pseudonoise (PN) codes at slightly different carrier frequencies, the coherent summation of the codes gives rise to a waveform whose shape is a function of both angle and range. In fact this is the consequence of applying the multiple-input multiple-output (MIMO) technique to the FDA, which has the result of associating a waveform to each point range/angle of the space, with the possibility of recovering this information in receive after appropriate processing.

Directions-of-Arrival Estimation Through Bayesian Compressive Sensing Strategies

Abstract: The estimation of the directions of arrival (DoAs) of narrow-band signals impinging on a linear antenna array is addressed within the Bayesian compressive sensing (BCS) framework. Unlike several state-of-the-art approaches, the voltages at the output of the receiving sensors are directly used to determine the DoAs of the signals thus avoiding the computation of the correlation matrix. Towards this end, the estimation problem is properly formulated to enforce the sparsity of the solution in the linear relationships between output voltages (i.e., the problem data) and the unknown DoAs. Customized implementations exploiting the measurements collected at a unique time instant (single-snapshot) and multiple time instants (multiple-snapshots) are presented and discussed. The effectiveness of the proposed approaches is assessed through an extensive numerical analysis addressing different scenarios, signal configurations, and noise conditions. Comparisons with state-of-the-art methods are reported, as well.

Wideband 400-Element Electronically Reconfigurable Transmitarray in X Band

Abstract: A fully electronically reconfigurable 400-element transmitarray is studied numerically and experimentally in X-band. The array operates in linear polarization and consists of 20 × 20 unit-cells. A 1-bit phase resolution has been selected for the unit-cell in order to reduce the complexity of the biasing network and steering logic, the insertion loss and the overall cost of the antenna system. The unit-cell stack-up is simple and is made of four metal layers: active side, biasing lines, ground plane and passive side. Two p-i-n diodes are integrated on the active side of each cell in order to control its transmission phase. The active array contains 800 diodes in total. It demonstrates experimentally pencil beam scanning over a 140 × 80-degree window over a 15.8% fractional bandwidth, with a maximum gain of 22.7 dBi at broadside. We also show that the same antenna array can be used for beam shaping applications (flat-top beam). The experimental results presented between 8 and 12 GHz are in good agreement with the theoretical performance calculated using full-wave electromagnetic simulations and an in-house CAD tool based on analytical modeling.

Wireless power orthogonal polarization antenna array

Abstract: Systems and methods for wireless power transmission are described herein In one aspect, an apparatus for wireless power transmission comprises a first antenna array of antenna coils configured to generate a first wireless field A second antenna array of antenna coils generates a second wireless field The first antenna array at least partially overlaps the second antenna array A driver circuit generates first and second drive signals for generation of the first and second wireless fields via the first and second antenna arrays, respectively The first wireless field is orthogonal with respect to the second wireless field The first antenna array and the driver circuit power the antenna coils of the first antenna array with alternating polarities The second antenna array and the driver circuit power the antenna coils of the second antenna array with alternating polarities

Remote charging system

Abstract: A charging device (200) is provided for communicating with one or more consumer devices (300) for remotely charging at least one of them upon demand of the consumer. The charging device (200) comprises a transmitter unit associated with an antenna unit comprising a power antenna configured to define at least one charging zone for transmitting charging power to the at least one charging zone; a receiver for receiving signals from consumers (300) located within the charging zone; and a controller unit. The controller is configured and operable to be responsive to a request signal from a consumer(300) indicative of demand for charging, to initiate a charging process of the consumer by radiation from the power antenna toward said consumer (300) to supply power required for operating a functional unit of said consumer(300). The power antenna may comprise an array of directional antenna elements, each defining the charging zone within a different angular segment of entire charging space defined by a radiation pattern of the antenna array.

Microstrip Magnetic Dipole Yagi Array Antenna With Endfire Radiation and Vertical Polarization

Abstract: A new microstrip Yagi array antenna with endfire radiation and vertical polarization is proposed. The Yagi antenna has a low profile, a wide bandwidth and a high gain. Each element of the Yagi array is based on a new microstrip antenna that has one edge opened and the other three edges shorted, working as a “magnetic dipole antenna”. As opposed to previous microstrip Yagi array antennas, the proposed Yagi antenna could produce a beam radiating at exactly endfire for infinite ground plane, with vertical polarization in the horizontal plane. A coupling microstrip line is introduced between the driven element and the first director element to strengthen the coupling between them, and therefore the front-to-back ratio and bandwidth of the array can be improved. The endfire gain can be enhanced as the number of the director elements increases, in either case where the array has an infinite or a finite ground plane.

Wideband High-Gain 60-GHz LTCC L-Probe Patch Antenna Array With a Soft Surface

Abstract: A 4 $\,\times\,$ 4 L-probe patch antenna array using multilayer low temperature co-fired ceramic (LTCC) technology is presented for 60-GHz band applications. The proposed antenna array is designed with a high gain in the impedance bandwidth by introducing a novel soft-surface structure. The soft-surface structure comprised of metal strips and via fences reduces the losses caused by severe surface waves and mutual coupling between adjacent elements to improve the radiation performance. The proposed antenna array is convenient for integrated applications. The fabricated antenna array excluding the measurement transition has dimension of 14.4 $\,\times\,$ 14.4 $\,\times\,$ 1 mm $^{3}$ . The simulated and measured impedance and radiation performance are studied and compared. Good agreement is achieved between simulation and measurement. The proposed antenna array shows a wide simulated impedance of 29% from 53 GHz to 71 GHz for $\vert {S}_{11}\vert dB, measured broadband 3-dB gain bandwidth of 18.3% from 54.5 GHz to 65.5 GHz and the gain up to 17.5 dBi at 60 GHz, respectively.

Multi-pair amplify-and-forward relaying with very large antenna arrays

Abstract: We consider a multi-pair relay channel where multiple sources simultaneously communicate with destinations using a relay. Each source or destination has only a single antenna, while the relay is equipped with a very large antenna array. We investigate the power efficiency of this system when maximum ratio combining/maximal ratio transmission (MRC/MRT) or zero-forcing (ZF) processing is used at the relay. Using a very large array, the transmit power of each source or relay (or both) can be made inversely proportional to the number of relay antennas while maintaining a given quality-of-service. At the same time, the achievable sum rate can be increased by a factor of the number of source-destination pairs. We show that when the number of antennas grows to infinity, the asymptotic achievable rates of MRC/MRT and ZF are the same if we scale the power at the sources. Depending on the large scale fading effect, MRC/MRT can outperform ZF or vice versa if we scale the power at the relay.

Antenna array with asymmetric elements

Abstract: An RFID reader is provided that includes an antenna array comprising multiple antenna elements circumferentially distributed around a longitudinal axis of the antenna array. Each antenna element includes multiple patch elements disposed above one or more underlying substrates, wherein the patch elements of each antenna element are disposed on an outer side of the antenna element. Further, one or more of the antenna elements is an asymmetric antenna element, wherein a first end of the asymmetric antenna element is wider than a second, opposite end of the asymmetric antenna element, wherein a first patch element disposed proximate to the first end of the asymmetric antenna element is larger than a second patch element disposed proximate to the second end of the asymmetric antenna element, and wherein a resonant frequency associated with the first patch element is approximately the same as a resonant frequency associated with the second patch element.

Circular antenna array for vehicular direction finding

Abstract: The circular antenna array for vehicular direction finding applications is a circular disc having a plurality of microstrip antennas radially spaced around the disc at equal angles. In one embodiment, the circular antenna array includes V-shaped antennas, and in another embodiment, the antennas are Yagi antennas. The circular antenna array can operate under two modes, switched and phased, in the 2.45 GHz band with an operating bandwidth of at least 100 MHz. The circular antenna array is configured to be installed in vehicles. Selective transmittal of an RF signal from a key fob generates a response signal from a specific antenna element receiving the RF signal in line with the direction of origin thereof. An LED panel indicates proximity and direction to the vehicle being located.

Method and apparatus for random access in communication system with large number of antennas

Abstract: A method for performing random access by a User Equipment (UE) in a wireless network, comprises configuring at least one UE transmit beam for a transmission of a random access signal, generating the at least one UE transmit beam using an antenna array according to the configuration, and transmitting the random access signal to a base station (BS) on the at least one UE transmit beam. An user equipment for performing random access in a wireless network, the User Equipment comprises a processing circuit configured to configure at least one UE transmit beam for a transmission of a random access signal, and generate the at least one UE transmit beam using an antenna array according to the configuration, and transmit the random access signal to the Base Station (BS) on the at least one UE transmit beam.

60-GHz Circularly Polarized U-Slot Patch Antenna Array on LTCC

Abstract: This communication presents a 60-GHz wideband circularly polarized (CP) U-slot patch antenna array of 4 × 4 elements on low temperature cofired ceramic (LTCC). A CP U-slot patch antenna is used as the array element to enhance the impedance bandwidth and a stripline sequential rotation feeding scheme is applied to achieve wide axial ratio (AR) bandwidth. Meanwhile, a grounded coplanar waveguide (GCPW) to stripline transition is designed for probe station measurement. The fabricated antenna array has a dimension of 14 ×16 × 1.1 mm3 . The simulated and measured impedance bandwidths, AR bandwidths, and radiation patterns are investigated and compared. Measured results show that the proposed antenna array has a wide impedance bandwidth from 50.5 GHz to 67 GHz for |S11| <; -10 dB, and a wide AR bandwidth from 54 GHz to 65.5 GHz for AR <; 3 dB. In addition, it exhibits a peak gain of 16 dBi and a beam-shaped pattern with 3-dB beam width of 20°. Moreover, its AR keeps below 3 dB within the 3-dB beam width.

Novel Dual-Broadband Planar Antenna and Its Array for 2G/3G/LTE Base Stations

Abstract: A novel dual-broadband planar antenna is proposed for 2G/3G/LTE (4G) mobile communications. The proposed dual-broadband antenna consists of one element for the lower band and two elements for the upper band, making it possible to be arrayed without appearance of grating lobes in the upper band. The lower-band element comprises a pair of printed dipoles with a pair of parasitic elements for bandwidth enhancement. Two upper-band elements composed of two pairs of folded dipoles are nested inside the lower-band element, forming a compact arrayable antenna unit. The dual-broadband antenna achieves a bandwidth of 20% (800-980 MHz) for the lower band and a bandwidth of 60% (1540-2860 MHz) for the upper band. A dual-broadband antenna array that consists of 4 elements for the lower band and 8 elements for the upper band is developed for base station applications. The dual-broadband array achieves a bandwidth of 22% (780-980 MHz) for the lower band and a bandwidth of 68% (1470-3000 MHz) for the upper band, covering all the frequency bands for 2G/3G/LTE (4G) systems. Measured antenna gains for the array are ~12 dBi for the lower band and dBi for the upper band, suitable for potential applications in mobile communication base stations.

A Broadband Focal Plane Array Camera for Real-time THz Imaging Applications

Abstract: We present a large-format, sub-millimeter-resolution, focal plane array sensor for THz imaging. Each pixel in the sensor array consists of broadband THz antennas monolithically integrated with ultra-fast heterostructure backward diodes for THz sensing. With the aid of in-house hybrid electromagnetic modeling tools, the focal plane array is optimized for diffraction limited image resolution and conjugate impedance matching for highest THz sensitivity. The camera is designed to operate in the 0.6–1.2 THz band with 5 frames-per-second image acquisition speeds, making it ideal for THz imaging applications, such as security screening, non-destructive evaluation and chemical, pharmaceutical, and medical imaging. The simulation results are validated by measurements to demonstrate sub-millimeter resolution with a pixel optical responsivity of 600 V/W at 0.7 THz.

Antenna having split directors and antenna array comprising same

Abstract: An antenna is provided comprising a pair of driven elements and a pair of passive elements. The driven elements are disposed on opposite sides of a reference plane, and the passive elements are also disposed on opposite sides of the reference plane. One or both passive elements may be provided in a different plane than the driven elements. By varying placement of the passive elements the antenna radiation pattern can be altered. An antenna array is also provided, comprising two or more oppositely directed directional antennas at least one of which is as described above. The passive elements of the antennas can be adjusted for a desired coverage pattern of the array, such as an azimuthal omnidirectional pattern, for example through simulation. The antenna or array may be embodied on a printed circuit board.

Robust Adaptive Beamforming Based on Low-Complexity Shrinkage-Based Mismatch Estimation.

Abstract: In this work, we propose a low-complexity robust adaptive beamforming (RAB) technique which estimates the steering vector using a Low-Complexity Shrinkage-Based Mismatch Estimation (LOCSME) algorithm. The proposed LOCSME algorithm estimates the covariance matrix of the input data and the interference-plus-noise covariance (INC) matrix by using the Oracle Approximating Shrinkage (OAS) method. LOCSME only requires prior knowledge of the angular sector in which the actual steering vector is located and the antenna array geometry. LOCSME does not require a costly optimization algorithm and does not need to know extra information from the interferers, which avoids direction finding for all interferers. Simulations show that LOCSME outperforms previously reported RAB algorithms and has a performance very close to the optimum.

Mutual Coupling in Phased Arrays: A Review

Abstract: The mutual coupling between antenna elements affects the antenna parameters like terminal impedances, reflection coefficients and hence the antenna array performance in terms of radiation characteristics, output signal-to-interference noise ratio (SINR), and radar cross section (RCS). This coupling effect is also known to directly or indirectly influence the steady state and transient response, the resolution capability, interference rejection, and direction-of-arrival (DOA) estimation competence of the array. Researchers have proposed several techniques and designs for optimal performance of phased array in a given signal environment, counteracting the coupling effect. This paper presents a comprehensive review of the methods that model and mitigate the mutual coupling effect for different types of arrays. The parameters that get affected due to the presence of coupling thereby degrading the array performance are discussed. The techniques for optimization of the antenna characteristics in the presence of coupling are also included.

Antenna array with reduced mutual coupling between array elements

Abstract: An array of antenna feed elements includes a plurality of horns, each horn having an aperture and configured for transmission of electromagnetic energy therethrough. At least a first horn is configured with an electrically conductive external surface proximate to the aperture, the external surface contoured so as to reduce mutual coupling between the first horn and an adjacent horn. Where the electromagnetic energy is within a radio frequency (RF) band, the external surface is contoured so as to provide an abrupt change in a gap dimension between the first horn and an adjacent horn, the change occurring at a distance behind the aperture of equal to a multiple of one half the characteristic wavelength of the RF band.

Apparatus and method for channel-state-information pilot design for an advanced wireless network

Abstract: A base station and mobile station communicate using a multiple input multiple output (MIMO) communication. The base station includes a two dimensional (2D) antenna array comprising a number N of antenna elements configured in a 2D grid. The 2D antenna array is configured to communicate with at least one subscriber station. The base station also includes a controller configured to transmit N channel-state-information reference-signal (CSI-RS) antenna ports (APs) associated with each of the N antenna elements. The subscriber station includes an antenna array configured to communicate with at least one base station. The subscriber station also includes processing circuitry configured receives physical downlink shared channels (PDSCHs) from a 2D active antenna array at the at least one base station. The 2D active antenna array includes a number N antenna elements. The processing circuitry further configured to estimate a full CSI associated with the N antenna elements.

A Compact 4 $\times$ 4 Planar UWB Antenna Array for 3-D Breast Cancer Detection

Abstract: A compact 4 × 4 planar ultrawideband (UWB) antenna array with the total size of 44 × 52.4 mm was developed for radar-based breast cancer detection system. The center frequency and the bandwidth of the antenna were 6 and 12.5 GHz, respectively. The breast phantom materials were developed to fit the characteristics of the measured human breast tissues. A quasi-three-dimensional confocal imaging was performed using the breast phantoms. It was confirmed that the compact 4 × 4 antenna array could detect a 5 × 5 × 5-mm3 tumor phantom in an inhomogeneous structure with a glandular phantom and resolve the two separate tumor phantoms, which were located at the depth of 23 mm with the spacing of 10 mm.

Parasitic Antenna Arrays for Wireless MIMO Systems

Abstract: This book unites two different technologies: parasitic antenna arrays driven via analogue circuits that control the electromagnetic waves generated by the antenna array; and MIMO technology for multi-antenna arrays, typically driven by digital techniques in the baseband domain. The combination of these two technologies has revealed a novel functionality that breaks through the conventional MIMO paradigm, allowing MIMO transmission over the air with the use of antenna arrays that may consist of only a single active element, that is surrounded by a number of passive neighboring antennas. The contributions in the book show the capability of such systems to also perform MIMO transmission. This fact holds the potential of revolutionizing the way small-form wireless terminals operate and seems to set the scene for a win-win situation, achieving MIMO transmission with very small and cheap antenna arrays. The book is structured to provide a well-rounded treatment of the various facets of this newly discovered wireless communication capability. All relevant technical angles, ranging from information theoretic to electromagnetic considerations; from analogue circuit to digital baseband control for signal generation; and from channel modeling to communication theoretic aspects are taken into account. A good balance between theory, practical considerations and over-the-air experimentation is proposed and reflected in the chapter outline. Finally, a discussion and early evidence related to potential applications as well as the relevance to current and upcoming wireless standards is provided.

Antenna system for ultra-wideband radar applications

Abstract: Antenna systems suitable for ultra-wideband radar applications, e.g. ground penetrating radar, through-wall radar systems, are disclosed in which backward electromagnetic radiation leakage, which is detrimental to antenna performance, is eliminated, and thereby enhancing the forward radiation performance of the antenna system. This necessarily results in insignificant electromagnetic interference to proximate antenna systems. Accordingly, an antenna array may be provided in which multiple antenna systems may be juxtaposed to one another even without a gap between adjacent antenna systems.

MIMO Radar and Ground-Based SAR Imaging Systems: Equivalent Approaches for Remote Sensing

Abstract: Currently there is an increasing interest in multiple-input multiple-output (MIMO) radars, because MIMO technology is able to provide a level of performance similar to that of a conventional antenna array, while also providing hardware and cost-related benefits. In this paper, we describe an upgrade of an existing ground-based synthetic aperture radar system (which is used for landslide monitoring) to a low-cost MIMO system. We also describe the associated low-cost/high-performance remote sensing benefits that this new configuration provides and present the results gathered by the new system. We conclude by outlining two configurations of the MIMO system with particular emphasis on antenna positioning, which has a key role in the overall performance.

An Integrated Microwave Imaging Radar With Planar Antennas for Breast Cancer Detection

Abstract: The system design of an integrated microwave imaging radar for the diagnostic screening of breasts cancer is presented. A custom integrated circuit implemented in a 65-nm CMOS technology and a pair of patch antennas realized on a planar laminate are proposed as the basic module of the imaging antenna array. The radar operates on the broad frequency range from 2 to 16 GHz with a dynamic range of 107 dB. Imaging experiments carried out on a realistic breast phantom show that the system is capable of detecting tumor targets with a resolution of 3 mm.

Broadband Circularly Polarized Slot Antenna Array Using Sequentially Rotated Technique for $C$ -Band Applications

Abstract: This letter presents the investigation results on a novel circularly polarized square-slot antenna (CPSSA) array designed to operate at a frequency of 5.5 GHz. In order to realize the proposed antenna array, four miniature circular polarized square-slot antennas are used with L-shape grounded strips located at the slots' opposite corners to reduce cross polarization. The antenna is fed by symmetric coplanar waveguide. The CPSSA element achieves a bandwidth of 16.6% for an axial ratio $\leq 3~$ dB. The CPSSA's performance is further enhanced with the construction of a novel 2 $\,\times\,$ 2 antenna array that is designed using sequentially rotated feed technique. The 3-dB axial ratio of the array extends to approximately 2 GHz with an impedance bandwidth of 31%. The CPSSA array was designed to operate over the frequency range between 4 and 6.825 GHz corresponding to an impedance bandwidth of 52% for ${\rm VSWR} (1.71:1). Acceptable agreement between the simulation and measured results validates the proposed design.

Reduction of the Envelope Correlation Coefficient With Improved Total Efficiency for Mobile LTE MIMO Antenna Arrays: Mutual Scattering Mode

Abstract: A mutual scattering mode is introduced in this paper. Utilizing this mode, the correlation of a lossy long-term evolution (LTE) multiple-input and multiple-output (MIMO) antenna array can be reduced efficiently, even down to zero, by increasing the Q factors of the MIMO antenna elements. In practice, the Q factors can be straight forwardly tuned through different input impedance matching. The zero correlation occurs at a Q factor higher than that resulting from the conjugate input impedance matching. On one hand, if the inter-element distance is larger than a certain distance (what we denominate as the Critical Distance), the total efficiency can also be improved in addition to reducing the correlation. On the other hand, when the inter-element distance is less than the critical distance, a reference MIMO antenna with high correlation and high total efficiency is obtained. This antenna can well be proposed for over-the-air (OTA) measurement applications. The introduced scattering mode is investigated for dual monopoles on a large lossy ground plane and for various mobile terminal MIMO antenna designs. A wideband MIMO antenna, with multiple resonances, covering the band 746-870 MHz is proposed with the envelope correlation coefficient and total efficiency less than 0.5 and higher than 50% (-3 dB), respectively. Measurements and simulations agree well for all the fabricated prototypes. The envelope correlations and the multiplexing efficiencies of the prototypes are also investigated in propagation channels with Gaussian distributed angle of arrivals.