Showing papers on "Phased array published in 2019"

A 28-GHz CMOS Phased-Array Transceiver Based on LO Phase-Shifting Architecture With Gain Invariant Phase Tuning for 5G New Radio

Abstract: This paper presents a 28-GHz CMOS four-element phased-array transceiver chip for the fifth-generation mobile network (5G) new radio (NR). The proposed transceiver is based on the local-oscillator (LO) phase-shifting architecture, and it achieves quasi-continuous phase tuning with less than 0.2-dB radio frequency (RF) gain variation and 0.3°C phase error. Accurate beam control with suppressed sidelobe level during beam steering could be supported by this work. At 28 GHz, a single-element transmitter-mode output ${{\mathrm {P}}_{\mathrm {1\,dB}}}$ of 15.7 dBm and a receiver-mode noise figure (NF) of 4.1 dB are achieved. The eight-element transceiver modules developed in this work are capable of scanning the beam from −50° to +50° with less than −9-dB sidelobe level. A saturated equivalent isotropic radiated power (EIRP) of 39.8 dBm is achieved at 0° scan. In a 5-m over-the-air measurement, the proposed module demonstrates the first 512 quadrature amplitude modulation (QAM) constellation in the 28-GHz band. A data stream of 6.4 Gb/s in 256-QAM could be supported within a beam angle of ±50°. The achieved maximum data rate is 15 Gb/s in 64-QAM. The proposed transceiver chip consumes 1.2 W/chip in transmitter mode and 0.59 W/chip in receiver mode.

Development, Implementation, and Characterization of a 64-Element Dual-Polarized Phased-Array Antenna Module for 28-GHz High-Speed Data Communications

Abstract: Silicon-based millimeter-wave (mm-wave) phased-array technologies are enabling directional wireless data communications at Gb/s speeds. In this paper, we review and discuss the challenges of implementing a multichip phased-array antenna module for mm-wave applications using organic buildup substrate technology. A prototype test vehicle has been fabricated and studied to evaluate the antenna and interconnect performance, dielectric properties, package substrate warpage conditions at different temperatures, chip- and board-level joint process reliability, and thermal management feasibility for cooling. Based on the learning from the test vehicle, an organic-based multilayered phased-array antenna package for 28-GHz mm-wave radio access applications is implemented. The package incorporates 64 dual-polarized antenna elements and features an air cavity common to all antennas. Direct probing measurements on a single-antenna element of the package show over 3 GHz of bandwidth and 3-dBi gain at 28 GHz. A phased-array transceiver module has been developed with the package; the module includes four SiGe BiCMOS ICs attached using flip-chip assembly. Module-level measurements in the TX mode show a 35-dB near-ideal output power increase for 64-element power combining; 64-element radiation pattern measurements are reported with a steering range of ± 50° without tapering in off-boresight directions, and 64-element radiation pattern measurements with tapering show achievement of a sidelobe level lower than −20 dB. The transceiver modules achieved 20.64-Gb/s throughput with 256 QAM and 800-MHz bandwidth in direct over-the-air link measurement results.

Integrated Millimeter-Wave Wideband End-Fire 5G Beam Steerable Array and Low-Frequency 4G LTE Antenna in Mobile Terminals

Abstract: In this paper, a novel technique of collocating a millimeter-wave end-fire 5G beam steerable array antenna with a low-frequency planar inverted-F antenna (PIFA) is presented. In this technique, the low-frequency antenna can be transparent by using some grating strips between the low- and high-frequency antennas. A quad-element mm-wave array with end-fire radiation patterns operating in 22–31 GHz is integrated with a dual-band low-frequency PIFA in a mobile terminal. The novelty of this paper is the collocation of a high-frequency end-fire 5G antenna array with an old-generation low-frequency antenna, such as 4G in small space in the mobile terminal, without interfering with the radiation pattern and impedance matching of both low- and high-frequency antennas. The proposed 5G antenna covers 22–31 GHz and can scan ±50° with the scan loss of better than 3 dB. The coverage efficiency of the proposed mm-wave 5G antenna is better than 50% and 80% for a minimum gain of 4 and 0 dBi in 22–31 GHz, respectively. The gain of the high-frequency antenna array is better than 9.5 dBi at 28 GHz. The low-frequency antenna covers some practical 4G LTE bands from 740–960 MHz and 1.7–2.2 GHz bands. The measured results in both low and high frequencies agree well with the simulations.

Dual-Linear Polarized Phased Array With 9:1 Bandwidth and 60° Scanning Off Broadside

Abstract: We present, for the first time, a novel dual-linear polarized tightly coupled dipole array with integrated balun operating across a 9:1 bandwidth, from 2 to 18 GHz. This dual-linear polarized array employs a tightly coupled dipole topology and scans down to 60° from boresight. The overall geometry consists of cross-located tightly coupled dipoles integrated with a folded Marchand balun that serves as an impedance transformer to achieve a wideband feeding network. Notably, the traditional dielectric superstrate is replaced with double layers of frequency selective surfaces to enable scanning down to 60° in both E-, H-, and diagonal (D)-planes across the entire band. The design achieves VSWR $\lambda _{low}$ /10). The design is validated through fabrication and testing of an $11 \times 11$ prototype. The measurements of this prototype are presented and are in good agreement with simulations.

Cognitive radar antenna selection via deep learning

Abstract: Direction-of-arrival (DoA) estimation of targets improves with the number of elements employed by a phased array radar antenna. Since larger arrays have high associated cost, area and computational load, there is a recent interest in thinning the antenna arrays without loss of far-field DoA accuracy. In this context, a cognitive radar may deploy a full array and then select an optimal subarray to transmit and receive the signals in response to changes in the target environment. Prior works have used optimisation and greedy search methods to pick the best subarrays cognitively. In this study, deep learning is leveraged to address the antenna selection problem. Specifically, they construct a convolutional neural network (CNN) as a multi-class classification framework, where each class designates a different subarray. The proposed network determines a new array every time data is received by the radar, thereby making antenna selection a cognitive operation. Their numerical experiments show that the proposed CNN structure provides 22% better classification performance than a support vector machine and the resulting subarrays yield 72% more accurate DoA estimates than random array selections.

A Concurrent Dual-Beam Phased-Array Doppler Radar Using MIMO Beamforming Techniques for Short-Range Vital-Signs Monitoring

Abstract: This paper presents the theoretical and experimental results of a new approach for multitarget vital-signs monitoring using an electromagnetic-based Doppler radar. A phased-array radar is designed and implemented using a hybrid beamforming architecture to generate two simultaneous beams. The proposed system significantly mitigates the phase collision problem in the presence of multiple targets. Comprehensive discussions on the theory of multibeam systems alongside detailed simulations are provided. For the purpose of demonstration, a prototype dual-beam phased-array continuous-wave Doppler radar has been designed and implemented at 2.4 GHz. The system is fully characterized, and the measurement results confirm the feasibility of the proposed method. The experimental measurements show that for the first time, the breathing rates of two individuals can be monitored at the same time and using the same frequency. Several practical aspects of the system are examined, and a pilot study on the subject tracking is presented. The proposed dual-beam system prevents the phase collision of the signatures of the targets and hence provides multiperson detection capability to the system.

A Transmission-Line-Based Decoupling Method for MIMO Antenna Arrays

Abstract: A transmission-line-based decoupling technique for dual-polarized multiple-input and multiple-output (MIMO) antenna arrays is presented and analyzed. The proposed scheme enables well-canceled coupling for the adjacent elements under co-polarization, without degrading the isolation of the cross-polarized ports. First, a decoupling network based on the presented method for a $2 \times 2$ MIMO array is provided, along with a comprehensive design procedure. Calculations and simulations are operated to verify decoupling performance. For further verification, a $2 \times 2$ dual-polarized patch array with the proposed decoupling method is developed. The decoupling network characterizes low profile, compact size, and low insertion loss, which is realized in a single layer. Measurements denote that the isolations between the co-polarized elements are improved from 16 to 20 dB to over 30 dB after decoupling at the center frequency of 2.45 GHz. Subsequently, based on the proposed $2 \times 2$ decoupling method, a decoupling network for large-scale dual-polarized MIMO arrays is presented. A design example of a $4 \times 4$ dual-polarized patch antenna array is established. Full-wave simulations indicate that the isolations are enhanced to better than 30 dB with a small insertion loss of less than 0.45 dB and can widely be used for phased array and massive MIMO array systems.

Real-Time Millimeter-Wave MIMO Channel Sounder for Dynamic Directional Measurements

Abstract: In this paper, we present a novel real-time multiple-input multiple-output (MIMO) channel sounder for the 28 GHz band. Until now, most investigations of the directional characteristics of millimeter-wave channels have used mechanically rotating horn antennas. In contrast, the sounder presented here is based on a phased array structure that performs fast electronic steering of the beams in the horizontal and vertical domains. This approach drastically shortens the measurement times for measurements that are directionally resolved both at the transmitter (TX) and the receiver (RX), and the measurement time per location is reduced from minutes or hours to milliseconds. This not only enables measurement of more TX–RX locations for a better statistical validity but also allows to perform directional analysis in dynamic environments. The sounder also has high phase stability, which, in conjunction with the short measurement time, leads to a low phase drift between TX and RX. This in turn enables phase-coherent sounding of all beam pairs even when TX and RX have no cabled connection for synchronization, and thus avoids any delay ambiguity. Furthermore, the phase stability over time enables complex RX waveform averaging to improve the signal-to-noise ratio during high path loss measurements. The paper discusses the system design as well as the measurements performed for verification of the sounder performance. Furthermore, we present sample results from double directional measurements in dynamic environments.

Phased Array Shaped-Beam Satellite Antenna With Boosted-Beam Control

Abstract: This communication presents a beamforming shaped-beam satellite (SBS) antenna based on a phased array technique and a boosted-beam control. The presented SBS antenna is specifically designed to cover the whole regions of Korea including the southern and northern areas. The proposed SBS antenna consists of waveguide feed network, beamforming circuits, waveguide circular polarizers, 19 radiation elements, and a boosted-beam control panel with active component calibration for temperature variation. To maximize the flexible performance, boosted-beam mode is supported to meet the required high-power signal regardless of bad weather conditions. The adjustable effective isotropic radiated power (EIRP) range was around 6 dB and there are a total of 19 beamforming units each configured by drive amplifier, phase shifter, and attenuator. Also, one extra beamforming unit synchronized with the other 19 elements is integrated for active component calibration. Each beamforming element can control relative phase shift up to 360° with 5° step and relative amplitude variation up to 10 dB with 1 dB step as well. Also, each radiation element is configured by waveguide horn and the return losses were better than 25 dB at 21 GHz.

Ultrasonic phased array inspection of a Wire + Arc Additive Manufactured (WAAM) sample with intentionally embedded defects

Abstract: In this study, Wire + Arc Additive Manufacture (WAAM) was employed to manufacture a steel specimen with intentionally embedded defects which were subsequently used for calibration of an ultrasonic phased array system and defect sizing. An ABB robot was combined with the Cold Metal Transfer (CMT) Gas Metal Arc (GMA) process to deposit 20 layers of mild steel. Tungsten-carbide balls (o1-3 mm) were intentionally embedded inside the additive structure after the 4th, 8th, 12th and 18th layers to serve as ultrasonic reflectors, simulating defects within the WAAM sample. An ultrasonic phased array system, consisting of a 5 MHz 64 Element phased array transducer, was used to inspect the WAAM sample non-destructively. The majority of the reflectors were detected successfully using Total Focusing Method (TFM), proving that the tungsten carbide balls were successfully embedded during the WAAM process and also that these are good ultrasonic reflectors. Owing to a lack of standards and codes for the ultrasonic inspection of WAAM samples (Lopez et al., 2018), a calibration method and step-by-step inspection strategy were introduced and then used to estimate the size and shape of an unknown lack of fusion (LoF) indication. This was then validated by destructive analysis, showing a good correlation with the phased array results.

Practical Implementation of Wideband and Wide-Scanning Cylindrically Conformal Phased Array

Abstract: A practical implementation of wideband and wide-scanning cylindrically conformal phased array is presented in this communication. First, the design of a dual-polarized planar array is introduced in advance. Then, as a preliminary performance investigation of a conformal phased array, a single-polarized array element counterpart is developed from the dual-polarized planar array with simple modifications. Finally, a conformal array is implemented using the $8 \times 8$ single-polarized radiating elements that are axially mounted onto a cylindrical surface with a radius of 150 mm. A conformal array prototype is fabricated and measured. The experimental results demonstrate that the array achieves active VSWR less than 3.0 over a bandwidth of 6–18 GHz (3:1), within a wide-scanning range of ±60° in two principal planes. The measured results are in good accordance with the simulations, thus validating the performances of the proposed wideband and wide-scanning cylindrically conformal phased array.

A flexible phased array system with low areal mass density

Abstract: Phased arrays are multiple antenna systems capable of forming and steering beams electronically using constructive and destructive interference between sources. They are employed extensively in radar and communication systems but are typically rigid, bulky and heavy, which limits their use in compact or portable devices and systems. Here, we report a scalable phased array system that is both lightweight and flexible. The array architecture consists of a self-monitoring complementary metal–oxide–semiconductor-based integrated circuit, which is responsible for generating multiple independent phase- and amplitude-controlled signal channels, combined with flexible and collapsible radiating structures. The modular platform, which can be collapsed, rolled and folded, is capable of operating standalone or as a subarray in a larger-scale flexible phased array system. To illustrate the capabilities of the approach, we created a 4 × 4 flexible phased array tile operating at 9.4–10.4 GHz, with a low areal mass density of 0.1 g cm−2. We also created a flexible phased array prototype that is powered by photovoltaic cells and intended for use in a wireless space-based solar power transfer array. By combining a CMOS-based integrated circuit with flexible and collapsible radiating structures, a scalable phased array architecture can be fabricated that has an areal mass density of only 0.1 g cm−2.

A Modular Architecture for Wide Scan Angle Phased Array Antenna for K/Ka Mobile SATCOM

Abstract: In this paper a low cost/complexity modular architecture for electronically scanned active phased array antenna (A-PAA) for high throughput K/Ka-band mobile satellite communication (SATCOM) is presented. With this approach, A-PAAs of any size, shape, and configuration can be built of intelligent building blocks (active sub-array modules) to minimize the design complexity and fabrication cost. The design and fabrication aspects of K/Ka A-PAA with wide scanning angle range is presented. The measured results of the modular array show that the antenna main beam can be steered to ± 70o off the boresight at 20/30 GHz. Furthermore, the antenna is able to achieve EVM ~ 7.60 % during the constellation test for 16 QAM and 1.2 Gb/s.

Acoustical boundary hologram for macroscopic rigid-body levitation.

Abstract: In previous studies, acoustical levitation in the far-field was limited to particles. Here, this paper proposes the “boundary hologram method,” a numerical design technique to generate a static and stable levitation field for macroscopic non-spherical rigid bodies larger than the sound wavelength λ. This paper employs boundary element formulation to approximate the acoustic radiation force and torque applied to a rigid body by discretizing the body surface, which is an explicit function of the transducer's phase and amplitude. Then, the drive of the phased array is numerically optimized to yield an appropriate field that stabilizes the body's position and rotation. In experiments, this paper demonstrates the levitation in air of an expanded polystyrene sphere with a diameter of 3.5 λ and a regular octahedron with diagonal length of 5.9 λ, both located 24 λ from the acoustic elements, by a 40 kHz (λ = 8.5 mm) ultrasonic phased array. This method expands the variety of objects that can be levitated in the far-field of an ultrasonic phased array.

A Novel 2-D $3\times3$ Nolen Matrix for 2-D Beamforming Applications

Abstract: In this paper, a 2-D beamforming phased array using a novel 2-D Nolen matrix network is presented. The Nolen matrix is a novel antenna feeding network composed of only couplers with dedicated coupling ratios and phase shifters. It does not require crossover and load termination compared to other networks based on Butler and Blass matrix. To be specific, the closed-form equations are derived first for uniplanar single $3 \times 3$ Nolen matrix, which is composed of three couplers and three phase delay lines. Most importantly, it is found that the proposed Nolen matrix can employ couplers with arbitrary phase differences to achieve relatively flexible progressive phase delays across the radiating elements, presenting a high degree of freedom on circuit topology and beamforming performance. Then, a 2-D antenna feeding network is designed by stacking and cascading six $3 \times 3$ Nolen matrices, and a 2-D patch antenna array is integrated with the proposed feeding network to generate nine radiation beams with unique directions on azimuth and elevation planes, realizing the 2-D beamforming function. To verify the proposed design concept, a prototype of 2-D beamforming phased array operating at 5.8 GHz is designed, fabricated, and measured, and the experimental results agree well with simulation and theoretical analysis.

A 37-40 GHz Phased Array Front-end with Dual Polarization for 5G MIMO Beamforming Applications

Abstract: This paper presents a dual polarized 37-40 GHz transmitter-receiver (TRX) phased array front-end RFIC implemented in a 28nm bulk RF-CMOS process. The TRX front-end contains 8 channels, 4-vertical (V) and 4-horizontal (H). Each transmit (TX) or receive (RX) channel consists of PA or LNA, 5-bit passive phase shifter, coarse and fine gain control amplifiers. The TX channel shows an op1dB of 10.2 dBm at the antenna bump. The RX channel shows a noise figure (NF) of 6 dB. TX and RX channels show an EVM of -32.57 dB and -29.80 dB respectively. A 4×4 antenna array was implemented on PCB using 4 TRX front-end RFICs. Beam patterns with different 5G-modulated waveforms were characterized.

N × N optical phased array with 2N phase shifters

Abstract: Two-dimensional (2-D) integrated optical phased arrays (OPA) have many applications from optical imaging to LiDAR. Conventionally, 2-D beam-steering in an N × N OPA requires N2 phase shifters placed within the phased array aperture, resulting in a high per-element power consumption while limiting the minimum achievable element-to-element spacing. In this paper, we report an OPA architecture, where for 2-D beam-steering in an N × N OPA, only 2N phase shifters outside of the array aperture are used, which significantly reduces the total OPA power consumption and eliminates electrical routing within the aperture. As a proof of concept, an 8 × 8 OPA is implemented that uses 16 phase shifters to perform 2-D beam-steering without tuning the wavelength. Using the aperture size of 77 µm × 77 µm for the implemented OPA transmitter, far-field beam-steering over a range of about 7° is demonstrated.

MM-Wave Phased Array Quasi-Yagi Antenna for the Upcoming 5G Cellular Communications

Abstract: The focus of this manuscript was to propose a new phased array antenna design for the fifth generation (5G) mobile platforms. Eight elements of compact Quasi-Yagi antennas were placed on the top portion of smartphone printed circuits board (PCB) to form a beam-steerable phased array design. The −10 dB impedance-bandwidth of proposed 5G smartphone antenna spans from 25 GHz to 27 GHz providing 2 GHz bandwidth with less than −16 dB mutual coupling function. A coax-to-microstripline with a truncated crown of vias around the coaxial cable was used as a feeding mechanism for each radiation element. An Arlon Ad 350 substance with properties of e = 3.5, δ = 0.003, and h = 0.8 mm was chosen as the antenna substrate. The proposed phased array antenna provides wide-angle scanning of 0°~75° with more than 10 dB realized gain levels. For the scanning angle of 0°~60°, the antenna array provides more than 90% (−0.5 dB) radiation and total efficiencies. In addition, the specific absorption rate (SAR) function and radiation performance of the design in the presence of the user-hand/user-hand have been studied. The results validate the feasibility of the proposed design for use in the 5G handheld devices. Furthermore, using the presented Quasi-Yagi elements, the radiation properties of 2 × 2, 4 × 4, and 8 × 8 planar arrays were studied and more than 8.3, 13.5, and 19.3 dBi directivities have been achieved for the designed planar arrays. The results show that the designed arrays (linear & planar) satisfy the general requirements for use in 5G platforms.

Ghost imaging using a large-scale silicon photonic phased array chip.

Abstract: We experimentally demonstrate the use of a large-scale silicon-photonic optical phased array (OPA) chip as a compact, low-cost, and potentially high-speed light illuminating device for ghost imaging (GI) applications. By driving 128 phase shifters of a newly developed silicon OPA chip using rapidly changing random electrical signals, we successfully retrieve a slit pattern with over 90 resolvable points in one dimension. We then demonstrate 2D imaging capability by sweeping the wavelength. With the potential of integrating high-speed phase modulators, tunable lasers, grating couplers, and CMOS driver circuit on the same silicon platform, this work paves the way towards realizing ultrahigh-speed and low-cost single-chip GI devices.

9.7 A Scalable 71-to-76GHz 64-Element Phased-Array Transceiver Module with 2×2 Direct-Conversion IC in 22nm FinFET CMOS Technology

Abstract: Fifth-generation cellular communication standards (5G) target Gb/s data-rates, pushing the industry beyond the sub-6GHz bands. Tens of GHz of spectrum are available in the frequency bands from 30 to 300GHz. To maintain acceptable link budgets with sufficient antenna apertures, arrays are typically required at these frequencies and electrical beam steering is needed to retain spatial coverage. For such complex systems, highly-integrated, low-cost and energy-efficient SoCs are desirable to enable volume deployment. FinFET technologies are an ideal candidate to tackle this challenging integration, given the excellent balance between density and RF/mm-wave performance that has been recently demonstrated [1].

Design and performance of an interferometric trigger array for radio detection of high-energy neutrinos

Abstract: Ultra-high energy neutrinos are detectable through impulsive radio signals generated through interactions in dense media, such as ice. Subsurface in-ice radio arrays are a promising way to advance the observation and measurement of astrophysical high-energy neutrinos with energies above those discovered by the IceCube detector ( ≥ 1 PeV) as well as cosmogenic neutrinos created in the GZK process ( ≥ 100 PeV). Here we describe the NuPhase detector, which is a compact receiving array of low-gain antennas deployed 185 m deep in glacial ice near the South Pole. Signals from the antennas are digitized and coherently summed into multiple beams to form a low-threshold interferometric phased array trigger for radio impulses. The NuPhase detector was installed at an Askaryan Radio Array (ARA) station during the 2017/18 Austral summer season. In situ measurements with an impulsive, point-source calibration instrument show a 50% trigger efficiency on impulses with voltage signal-to-noise ratios (SNR) of ≤ 2.0, a factor of ∼ 1.8 improvement in SNR over the standard ARA combinatoric trigger. Hardware-level simulations, validated with in situ measurements, predict a trigger threshold of an SNR as low as 1.6 for neutrino interactions that are in the far field of the array. With the already-achieved NuPhase trigger performance included in ARASim, a detector simulation for the ARA experiment, we find the trigger-level effective detector volume is increased by a factor of 1.8 at neutrino energies between 10 and 100 PeV compared to the currently used ARA combinatoric trigger. We also discuss an achievable near term path toward lowering the trigger threshold further to an SNR of 1.0, which would increase the effective single-station volume by more than a factor of 3 in the same range of neutrino energies.

Cooperative interactions between nano-antennas in a high-Q cavity for unidirectional light sources.

Abstract: We analyse the resonant mode structure and local density of states in high-Q hybrid plasmonic-photonic resonators composed of dielectric microdisks hybridized with pairs of plasmon antennas that are systematically swept in position through the cavity mode. On the one hand, this system is a classical realization of the cooperative resonant dipole–dipole interaction through a cavity mode, as is evident through predicted and measured resonance linewidths and shifts. At the same time, our work introduces the notion of ‘phased array’ antenna physics into plasmonic-photonic resonators. We predict that one may construct large local density of states (LDOS) enhancements exceeding those given by a single antenna, which are ‘chiral’ in the sense of correlating with the unidirectional injection of fluorescence into the cavity. We report an experiment probing the resonances of silicon nitride microdisks decorated with aluminium antenna dimers. Measurements directly confirm the predicted cooperative effects of the coupled dipole antennas as a function of the antenna spacing on the hybrid mode quality factors and resonance conditions.

A 0.53-THz Subharmonic Injection-Locked Phased Array With 63- $\mu$ W Radiated Power in 40-nm CMOS

Abstract: This paper presents a 0.53-THz subharmonic injection-locked $1\times 4$ phased array based on an injection-locked oscillator (ILO) chain. Thanks to the ILO chain, the phase errors in the phased array can be compensated without introducing power variation. This technique enables accurate beam steering with a 60° scan range in the $E$ -plane at 0.53 THz. A six-stage triple-push oscillator is proposed to generate the signal at 0.53 THz. Compared with a conventional triple-push oscillator, it reduces layout constraints, improves signal balance, and enhances output power by at least 3 dB. The phased array is implemented in 40-nm CMOS. With an injection power of 0 dBm, the injection-locked phased array generates an output frequency from 529 to 534 GHz. At 531.5 GHz, the proposed phased array achieves −12-dBm radiated power and 0.24‰ dc-to-terahertz (THz) efficiency without the use of silicon lens, quartz superstrate, or substrate thinning. The chip consumes 260-mW dc power and occupies an area of 2.5 mm2.

A Scalable Circularly-Polarized 256-Element Ka-Band Phased-Array SATCOM Transmitter with ±60° Beam Scanning and 34.5 dBW EIRP

Abstract: This paper presents a scalable 256-element Ka-band switchable dual-polarizrd phased-array SATCOM transmitter (TX). The phased-array can generate linear, rotated linear, clockwise and counter-clockwise polarization which can be selected by setting the phased shifters in the beamformer chips. The low-cost design uses FR-4 based printed circuit board (PCB), surface mount technology (SMT) and silicon beamformer chips. The phased-array can scan to ± 60° in the elevation plane with a 3-dB beamwidth of 7° and 34.5 dBW EIRP at broadside. It has a measured 3-dB instantaneous axial-ratio bandwidth of 2 GHz and is scalable without grating lobes to allow economical construction of larger phased-arrays. The compact size of (14 x 11.5 cm) makes it suitable for a low-cost Ka-band SATCOM terminal.

Erratum to “An Integrated Circularly Polarized Transmitter Active Phased-Array Antenna for Emerging Ka -Band Satellite Mobile Terminals”

Abstract: This paper presents the design, development, and measurement results of a low-cost integrated circularly polarized (CP) active phased-array antenna (CP-APAA) technology with sidelobe level (SLL) control, operating at $Ka$ -band, for high throughput land-mobile satellite communication. The proposed CP-APAA is comprised of ( $4\times 16$ ) 64 elements in a rectangular grid array configuration. Eight commercial monolithic monolithic microwave/millimeter-wave integrated circuit. (MMICs) with eight-RF output channels have been used to control the phase and amplitude over the antenna aperture. For simplicity, the array antenna was designed in three metal layers and fabricated by a low-cost printed circuit board (PCB) technology as a proof-of-concept for a modular and scalable $Ka$ -band PAA with a wide steering angle. Measured radiation pattern shows a right-hand CP (RHCP) pattern with an axial-ratio (AR) level < 3 dB and low pointing error ≤1.5° over a scanning angular range of 0° to ±40°. Moreover, the amplitude excitation of the CP-APAA was tapered exponentially to control and reduce the SLL from 11 to 25 dB in boresight direction. Finally, toward a multibeam array implementation, two RHCP beams have been simultaneously generated at −30° and +20° scan angles.

Development of a Compensation System Based on Horn Antennas for an Active Phased Antenna Array

Abstract: In an article the influence of active and passive interferences on the operation of active phased array antenna (APAA) of X-band radar are considered. A new way for interferences compensate to during APAA work is proposed. For implement this method, a new unit for interference compensation has been developed a based on horn antennas. The experimental investigation results of unit work, as a separate device, and as part of the radar station are presented.

Characterizations of Mutual Coupling Effects on Switch-Based Phased Array Antennas for 5G Millimeter-Wave Mobile Communications

Abstract: The fifth generation (5G) millimeter-wave (mmWave) handset demands a cost-effective mmWave array antenna with beam steering capability to overcome the high-pass loss and to ensure seamless connectivity. Unlike sub-6-GHz handsets, emerging mmWave handsets usually employ phased array antennas with a reasonably large number of elements. Unfortunately, due to the legacy of a few antennas in sub-6-GHz handsets, the mutual coupling effect on the mmWave handset has not been thoroughly investigated. In this paper, we study the mutual coupling effect on the mmWave handset performance by comparing array antennas with different inter-element spacing and different configurations. It is found that mutual coupling tends to increase the active reflection (especially at large scanning angles), which in turn reduces the realized gain and maximum scanning angle of the phased array antenna. For a sub-6-GHz multiple-input multiple-output handset with two or four antenna ports and fully digital precoding/decoding, 10-dB isolation is usually regarded as good enough. It is shown in this paper, however, that the outage capacity of the mmWave handset can be clearly improved by reducing the mutual coupling.