Showing papers on "Phased array published in 2022"
TL;DR: In this paper , a dual-polarized phased array antenna with wide-angle scanning capability is presented. And the proposed method can also optimize the array unit size and achieve a small inter-unit distance for wide-angles scanning capability.
Abstract: A dual-polarized phased array antenna is presented with wide-angle scanning capability in this paper. To improve the mutual coupling in the array, a current cancellation method (CCM) is proposed by changing the current distribution on the excited unit to induce a pair of the canceled currents on the adjacent unit. Meanwhile, this current distribution broadens the beam-width of the unit in the array. Besides, the proposed method can also optimize the array unit size and achieve a small inter-unit distance for wide-angle scanning capability. A low-profile dual-polarization antenna operating in the bandwidth from 4.4 GHz to 5.0 GHz is designed as a linear array and a planar array to verify the proposed method. Regardless of the linear array or planar array, the mutual coupling in the array is below -19 dB, which is better than that in conventional arrays. Meanwhile, the antenna unit in the array can radiate a wide-beam pattern. Two arrays can scan over ±60° for both polarizations. Within the scanning range, the realized gain reduction is less than 3 dB and the side-lobe level is lower than -7.5 dB. To verify the performance, two array antenna prototypes are fabricated and tested. The experimental results agree well with the simulation.
24 citations
TL;DR: To the author's knowledge, this work achieves the highest bandwidth phased array with a peak EIRP of 34 dBm enabling the construction of multi-standard/multi-band 5G phased-array systems.
Abstract: This article introduces a millimeter-wave (mm-wave) multi-band transmit (Tx) phased-array design supp- orting the fifth-generation (5G) new radio frequency range 2 (NR FR2) bands. An eight-element phased-array module is presented employing two wideband 16–52 GHz $4{\times }1$ Tx beamformer chips and tapered slot Vivaldi antenna array. The beamformer chips are designed in a SiGe BiCMOS process and flipped on a printed circuit board (PCB). The SiGe integrated circuit (IC) has four differential radio frequency (RF) beamforming channels each consisting of an active balun, analog adder-based phase shifter (PS), variable gain amplifier (VGA), and a two-stage class-AB power amplifier (PA). The RF input signal is distributed to the four channels using a compact Wilkinson network. The measured peak gain is 28.3 dB with 13.5–14.7 dBm output $P_{1{\mathrm {dB}}}$ and 14–15.4 dBm $P_{{\mathrm {sat}}}$ at 20–50 GHz. Each channel dissipates 250 mW from 2 V and 3-V supplies at $P_{1\,{\mathrm{ dB}}}$ . The beamformer chip is tested using 64-QAM waveforms and achieves a data rate of 2.4 Gb/s at 5.2% rms EVM and 9.6-dBm average power. The eight-element phased-array module shows a broadband performance with excellent patterns and ±60° scanning capability and with a peak effective isotropic radiated power (EIRP) of 32–34 dBm at 19.5–51 GHz. At an EIRP of 21–22 dBm, 400-MHz 256-QAM 5G-NR compliant waveforms are transmitted with < 2.98% EVM demonstrating 5G NR FR2 operation. To the author’s knowledge, this work achieves the highest bandwidth phased array with a peak EIRP of 34 dBm enabling the construction of multi-standard/multi-band 5G phased-array systems.
21 citations
TL;DR: In this paper , an eight-element phased-array receive module is demonstrated based on two four-channel wideband beamformer chips designed in the SiGe BiCMOS process and flipped on a low-cost printed circuit board.
Abstract: This work presents a 15–57 GHz multiband/ multistandard phased-array architecture for the fifth-generation (5G) new radio (NR) frequency range 2 (FR2) bands. An eight-element phased-array receive module is demonstrated based on two four-channel wideband beamformer chips designed in the SiGe BiCMOS process and flipped on a low-cost printed circuit board. The SiGe Rx chip employs RF beamforming and is designed to interface to a wideband differential Vivaldi antenna array. Each channel consists of a low-noise amplifier (LNA), active phase shifter with 5-bit resolution, variable gain amplifier (VGA), and differential-to-single-ended stage. The four channels are combined using a wideband two-stage on-chip Wilkinson network. The beamformer has a peak electronic gain of 24–25 dB and a 4.7–6.2 dB noise figure (NF) with a −29 to −24 dBm input $P_{\boldsymbol {1\,dB}}$ at 20–40 GHz. The eight-element phased-array module also achieved ultra-wideband frequency response with flat gain and low-system NF. The phased array scans ±55° with $ < -12$ -dB sidelobes demonstrating multiband operation. A 1.2-m over-the-air (OTA) link measurement using the eight-element Rx module supports 400-MHz 256-QAM OFDMA modulation with < 2.76% error vector magnitude (EVM) at multiple 5G NR FR2 bands. To the author’s knowledge, this work achieves the widest bandwidth phased array enabling the construction of multistandard systems.
20 citations
TL;DR: In this article , a weighted frequency diverse array (FDA) was proposed to suppress the range peak sidelobe as much as possible at the expense of raising other range sidelobes.
Abstract: The deceptive jamming technique can threaten a synthetic aperture radar (SAR) imaging system by repeatedly transmitting copied radar signals back to the radar. A conventional phased array can generate only an angle-dependent beam and cannot distinguish the jammer from other targets. Instead, a frequency diverse array (FDA) can offer a range-angle-dependent beampattern by introducing small frequency offsets to array elements, which can be adopted to distinguish signals from different range cells. Thus, considering that the position of the jammer is unknown, it is necessary to suppress the range peak sidelobe as much as possible. To lower this value, this communication proposes a weighted FDA to achieve the optimal solution at the expense of raising other range sidelobes.
17 citations
TL;DR: In this paper , an 8192-element optical phased array with individually-addressed elements driven by custom CMOS electronics is shown. And a solid-state coherent LiDAR system is realized with transmit/receive optical phased arrays coupled to an on-chip coherent receiver while being driven by the demonstrated laser.
Abstract: We present recent advancements of optical phased array LiDAR with record-performance system demonstrations. First, we give an overview of the technology and how it combines the benefits of coherent LiDAR with the integration capabilities of silicon photonics. Then, an 8192-element optical phased array is shown with individually-addressed elements driven by custom CMOS electronics. This compact chip-scale beam-steering engine is enabled by flip-chip attached ASICs on the photonic integrated circuit. The optical phase shifters and emitters in the array have a 1 $\mu$ $100^{\circ }\times 17^\circ$ $\sim$ $\mu$
16 citations
TL;DR: In the present method, the point-by-point scan is replaced by a single measurement for FRF with the “Single Input, Multiple Output” (SIMO) mode, which ensures the scan work can be established in N times excitations, which means the excitation waveform can be virtually selected and changed after recording.
16 citations
15 citations
TL;DR: In this article, an alternative ultrasonic phased array approach relying on the nonlinear modulation of dual-frequency excitation was introduced to improve the sensitivity and accuracy in the detection of contact defects.
13 citations
TL;DR: In this paper , the authors presented a scalable 17.7-20.2 GHz single printed circuit board (PCB) phased array with reconfigurable polarization, which is able to receive either linear, rotated linear, circular clockwise, or anticlockwise polarization, and demonstrated a measured 3.47° half-power beamwidth (HPBW), more than 25dB cross-polar discrimination (XPD), and +8.1dB/K gain to noise (G/T) per polarization, with more than 80dB Tx-band isolation.
Abstract: This article presents a wideband scalable 17.7–20.2-GHz 1024-element $K$ -band satellite communication (SATCOM) receive (Rx) phased array with reconfigurable polarization. The phased array uses silicon Rx beamformer (BF) chips and silicon low-noise amplifiers (LNAs) and is able to receive either linear, rotated linear, circular clockwise, or anticlockwise polarization. It demonstrates a measured 3.47° half-power beamwidth (HPBW), more than 25-dB cross-polar discrimination (XPD), and +8.1-dB/K gain-to-noise (G/T) per polarization, and has more than 80-dB Tx-band isolation. The phased array is able to scan to ±70° in all planes without grating lobes and $\cos ^{1-1.2}(\theta)$ scan loss. The array aperture measures 22.4 cm $\times22.4$ cm. To our knowledge, this is the largest single printed circuit board (PCB) SATCOM $K$ -band phased-array receiver to date with the highest G/T and represents the highest level of integration at millimeter waves.
13 citations
TL;DR: In this article , a SiN-on-SOI two-dimensional optical phased array (OSA) chip was designed and fabricated to achieve a 2D scanning range of 96°×14.4° and 690 mW peak power of the main lobe.
Abstract: Silicon based optoelectronic integrated optical phased array is attractive owing to large-dense integration, large scanning range and CMOS compatibility. In this paper, we design and fabricate a SiN-on-SOI two-dimensional optical phased array chip. We demonstrate a two-dimensional scanning range of 96°×14.4° and 690 mW peak power of the main lobe. Additionally, we set up the time of flight (ToF) and frequency-modulated continuous-wave (FMCW) ranging systems by using this optical phased array chip, and achieve the objects detection at the range of 20 m in the ToF system and 109 m in the FMCW system, respectively.
12 citations
TL;DR: In this article , a concept of a phased antenna array based on substrate integrated waveguide (SIW) technology for 5G base stations is proposed, which has a cosecant radiation pattern in the vertical plane for uniform illumination in a sector area.
Abstract: In this article, a concept of a phased antenna array based on substrate integrated waveguide (SIW) technology for 5G base stations is proposed. The array has a cosecant radiation pattern in the vertical plane for uniform illumination in a sector area. The array itself consists of 16 SIW traveling wave subarrays of 12 slot-coupled microstrip patch antennas associated with a pair of reflection-canceling vias and phasing elements to get the tapered distribution both in amplitude and phase for the cosecant-shaped radiation pattern. The array is designed to be operational at 28 GHz with a bandwidth of more than 10%, a candidate mm-wave frequency band for 5G. The phased antenna array supports wide-angle scanning of +/−60° in azimuth and exhibits good active impedance properties. The array design is successfully verified experimentally.
TL;DR: In this paper , a light-controlled reconfigurable metasurface (MS) with a controllable modulation range of reflection phase is proposed, and its unit is composed of a reflection phase element based on the varactor and an optical interrogation network (OIN) based on photoresistor.
Abstract: The reconfigurable metasurface (MS) with tunable electromagnetic scattering properties has had an impact on innovative communication applications. However, the widely studied MS controlled by direct-current (DC) bias requires complex physical control circuits in array wavefront encoding, while the light-controlled MS does not. In this paper, we report a new approach for a light-controlled MS with a controllable modulation range of reflection phase, and its unit is composed of a reflection phase element based on the varactor and an optical interrogation network (OIN) based on the photoresistor so that the phase distribution of each MS unit could be independently programmed optically. To illustrate our approach, a 2-bit reflection phase MS with 10 × 10 units was fabricated and tested to achieve pencil beam scanning and orbital angular momentum beam at microwave frequencies. The simulated and measured results verify the feasibility of the proposed design. Furthermore, all the OINs on the MS are connected in parallel and powered by the same DC voltage source, which simplifies the difficulty of array expansion in MS design with a large-scale array.
TL;DR: A time modulation strategy is introduced in the 1-bit transmissive programmable metasurface for reducing the SLLs of the generated patterns through the high-speed modulation of the real-time periodic coding sequences on the metAsurface by the programmable bias circuit.
Abstract: Programmable metasurfaces have great potential for the implementation of low-complexity and low-cost phased arrays. Due to the difficulty of multiple-bit phase control, conventional programmable metasurfaces suffer a relatively high sidelobe level (SLL). In this manuscript, a time modulation strategy is introduced in the 1-bit transmissive programmable metasurface for reducing the SLLs of the generated patterns. After the periodic time modulation, harmonics are generated in each reconfigurable unit and the phase of the first-order harmonic can be dynamically controlled by applying different modulation sequences onto the corresponding unit. Through the high-speed modulation of the real-time periodic coding sequences on the metasurface by the programmable bias circuit, the equivalent phase shift accuracy to each metasurface unit can be improved to 6-bit and thus the SLLs of the metasurface could be reduced remarkably. The proposed time-modulated strategy is verified both numerically and experimentally with a transmissive programmable metasurface, which obtains an aperture efficiency over 34% and reduced SLLs of about −20 dB. The proposed design could offer a novel approach of a programmable metasurface framework for radar detection and secure communication applications.
TL;DR: In this article , a novel mode of signal processing for the piezoelectric phased array is proposed based on the Frequency Response Function (FRF), where the point-by-point scan is replaced by a single measurement for FRF with the Single Input, Multiple Output (SIMO) mode, which ensures the scan work can be established in N times excitations (N is the number of pieziolectric wafer, much smaller than the amount of inspection points).
TL;DR: In this article , the authors presented the theory and design methodology of US WPT links with phased arrays and mm-sized receivers (Rx) for given constraints imposed by the application and fabrication, such as load and focal distance.
Abstract: Ultrasound (US) is an attractive modality for wireless power transfer (WPT) to biomedical implants with millimeter (mm) dimensions. To compensate for misalignments in WPT to a mm-sized implant (or powering a network of mm-sized implants), a US transducer array should electronically be driven in a beamforming fashion (known as US phased array) to steer focused US beams at different locations. This paper presents the theory and design methodology of US WPT links with phased arrays and mm-sized receivers (Rx). For given constraints imposed by the application and fabrication, such as load ( RL ) and focal distance ( F ), the optimal geometries of a US phased array and Rx transducer, as well as the optimal operation frequency ( fc ) are found through an iterative design procedure to maximize the power transfer efficiency (PTE). An optimal figure of merit (FoM) related to PTE is proposed to simplify the US array design. A design example of a US link is presented and optimized for WPT to a mm-sized Rx with a linear array. In measurements, the fabricated 16-element array (10.9×9×1.7 mm 3 ) driven by 100 V pulses at fc of 1.1 MHz with optimal delays for focusing at F = 20 mm generated a US beam with a pressure output of 0.8 MPa. The link could deliver up to 6 mW to a ∼ 1 mm 3 Rx with a PTE of 0.14% ( RL = 850 Ω). The beam steering capability of the array at -45 o to 45 o angles was also characterized.
12 Jun 2022
TL;DR: In this article , an inter-element mismatch compensation technique was introduced for improving the shared-LUT DPD performance over the PVT variations, and the measured 64-QAM OFDMA-mode EVM and ACLR were improved from −22.4dB to −25.0dB and from −28.7dBc to −32.1dBc, respectively.
Abstract: This work demonstrates a 39-GHz CMOS phased-array beamformer with the bi-directional Doherty PA-LNA. An inter-element mismatch compensation technique is introduced for improving the shared-LUT DPD performance over the PVT variations. By utilizing the proposed mismatch compensation, the measured 64-QAM OFDMA-mode EVM and ACLR with the shared-LUT DPD are improved from −22.4dB to −25.0dB and from −28.7dBc to −32.1dBc, respectively.
TL;DR: In this article , the authors presented an air-coupled ultrasonic phased array based on the Fermat spiral, capable of transmit, receive and pulse-echo operation, as well as 3D imaging.
Abstract: Sparse spiral phased arrays are advantageous for many emerging air-coupled ultrasonic applications, since grating lobes are prevented without being constrained to the half-wavelength element spacing requirement of well-known dense arrays. As a result, the limitation on the maximum transducer diameter is omitted and the aperture can be enlarged for improving the beamforming precision without requiring the number of transducers to be increased. We demonstrate that in-air imaging, in particular, benefits from these features, enabling large-volume, unambiguous and high-resolution image formation. Therefore, we created an air-coupled ultrasonic phased array based on the Fermat spiral, capable of transmit, receive and pulse-echo operation, as well as 3D imaging. The array consists of 64 piezoelectric 40-kHz transducers (Murata MA40S4S), spanning an aperture of 200mm. First, we provide an application-independent numerical and experimental characterization of the conventional beamforming performance of all operation modes for varying focal directions and distances. Second, we examine the resulting imaging capabilities using the single line transmission technique. Apart from the high maximum sound pressure level of 152 dB, we validate that unambiguous high-accuracy 3D imaging is possible in a wide field of view (±80°), long range (20cm to 5m+) and with a high angular resolution of up to 2.3°. Additionally, we demonstrate that object shapes and patterns of multiple reflectors are recognizable in the images generated using a simple threshold for separation. In total, the imaging capabilities achieved are promising to open up further possibilities, e.g. robust object classification in harsh environments based on ultrasonic images.
TL;DR: In this article , an alternative ultrasonic phased array approach relying on the nonlinear modulation of dual-frequency excitation was introduced to improve the sensitivity and accuracy in the detection of contact defects.
TL;DR: In this paper , a convolutional neural network model was established to recognize wrinkles at different depths with the short-time Fourier transform of waveforms, and the model training could be accelerated through simulation in PZFlex.
TL;DR: In this article , a low complexity technique to construct beams that are well suited for massive wideband phased arrays is proposed. But the technique is not suitable for near-field and far-field systems.
Abstract: Phased arrays, commonly used in IEEE 802.11ad and 5G radios, are capable of focusing radio frequency signals in a specific direction or a spatial region. Beamforming achieves such directional or spatial concentration of signals and enables phased array-based radios to achieve high data rates. Designing beams for millimeter wave and terahertz communication using massive phased arrays, however, is challenging due to hardware constraints and the wide bandwidth in these systems. For example, beams which are optimal at the center frequency may perform poor in wideband communication systems where the radio frequencies differ substantially from the center frequency. The poor performance in such systems is due to differences in the optimal beamformers corresponding to distinct radio frequencies within the wide bandwidth. Such a mismatch leads to a misfocus effect in near-field systems and the beam squint effect in far-field systems. In this paper, we investigate the misfocus effect and propose InFocus, a low complexity technique to construct beams that are well suited for massive wideband phased arrays. The beams are constructed using a carefully designed frequency modulated waveform in the spatial dimension. InFocus mitigates beam misfocus and beam squint when applied to near-field and far-field systems.
TL;DR: This article investigates the pattern synthesis of the conformal phased array antenna (PAA) by using the deep deterministic policy gradient (DDPG) algorithm, and a nearly full solid angle for beam steering is realized.
Abstract: This article investigates the pattern synthesis of the conformal phased array antenna (PAA) by using the deep deterministic policy gradient (DDPG) algorithm, and a nearly full solid angle for beam steering is realized. The beam steering capability of the planar and conformal PAAs is theoretically compared at first, and a conclusion is obtained that conformed to the conical-and-cylindrical structure can help to achieve ultrawide-angle beam steering. Next, a typical deep reinforcement learning algorithm, which is the DDPG algorithm, is utilized to deal with the fast beam steering problem of the conformal heterogeneous PAA. By virtue of the strong fitting ability of the DDPG algorithm for high-dimensional continuous nonlinear problems, the performance of fast beam steering is achieved within a wide-angle range within (−150°, 150°). Finally, a prototype of $1\times17$ conformal PAA is fabricated for measurement and verification, and the measured results are in good agreement with the simulation results.
27 Mar 2022
TL;DR: In this paper , a low-profile 5G phased array with improved radiation properties for smartphone applications is presented, which is capable of providing high-performance radiation beams at different scanning angles, even though it is designed on an FR-4 substrate.
Abstract: This paper presents a low-profile 5G phased array with improved radiation properties for smartphone applications. By modifying the structure of antenna elements from conventional slots to air-filled slot-loop resonators (with the same thickness of the substrate), the array is capable to provide high-performance radiation beams at different scanning angles, even though it is designed on an FR-4 substrate. The array contains eight slot-loop radiators. The employed elements have low profiles with discrete-feeding ports and they operate at 21-23.5 GHz. Moreover, the coupling of the radiators is less than −15 dB at the centre frequency. Well-defined and quasi end-fire radiation, good efficiency and gain levels, wide beam-steering wide operation band are the promising characteristics of the introduced array.
TL;DR: In this article , a beamforming metasurface that shifts the field manipulation from an electric level to an electromagnetic one is proposed for speeding up the IA procedure with respect to a traditional system using PAAs.
Abstract: Fifth-generation (and beyond) networks are characterized by ever more demanding requirements in terms of speed, bandwidth, and number of servable users. Fast and reliable access to the main network is mandatory, requiring technologies and procedures that ensure high performing cell search and initial access (IA). Existing phased array antennas (PAAs) are limited by the single beam scanning approach and complex feeding systems. In this paper, a beamforming metasurface that shifts the field manipulation from an electric level to an electromagnetic one is proposed for speeding up the IA procedure with respect to a traditional system using PAAs. The main advantage is given by the simultaneous transmission of multiple signals in different directions. The numerical results demonstrate that a much faster IA with similar success probability can be reached. Our system provides high gain, parallel computation, and scalability for larger systems, becoming a relevant candidate in the new radio and smart electromagnetic environment context.
TL;DR: In this article , the heat sink property of a 4x2 wideband dual linear polarized phased array antenna comprised of 3D metal printed all metallic radiators, serving also as heat sink, is presented for X-band frequency.
Abstract: In this paper, investigations on heat sink property of a 4x2 wideband dual linear polarized phased array antenna comprised of 3D metal printed all metallic radiators, serving also as heat sink, is presented for X-band frequency. Two single radiators, each with a height nearly equal to ${\lambda }$ /2 corresponding to center frequency (9.50 GHz), shaped intuitively and placed orthogonal to each other and surrounded by a metal ring of square cross-section with overall dimension of ${\lambda }/2\times {\lambda }$ /2, constitutes the dual linear polarized radiating element. Both radiators are fed by an orthogonal arrangement of stripline feeds through a trapezium shaped metal plate, which in turn helps to integrate the antenna aperture with the beamforming network (BFN). A set of via fences are placed beneath each antenna element, which work as a thermal path between the BFN and antenna aperture. This radiating element resembles heat fins, and designed to cover 8.5-11.5 GHz impedance bandwidth. Good radiation pattern with low cross-polarization is obtained over the entire bandwidth, while the peak broadside gain is varying between 14–11 dBi. Beam scans are viable ±50° in ${\varphi }=0^{0}$ plane and ±30° in ${\varphi }=90^{0}$ plane. The array antenna aperture is built using 3D metal printing technology. The BFN is comprised of commercial silicon Radio Frequency Integrated Circuit (RFIC) chips which have been integrated with the antenna aperture. A beamforming algorithm is applied through serial peripheral interface (SPI) controller to achieve beam steering during the measurement process. The temperature reduction of 60°C is achieved with the heat sink structure when the temperature distribution of BFN with and without heat sink are compared for the 4x2 array. The temperature of the heat sink antenna is only 41°C and the temperature distribution is validated with an infrared (IR) camera.
20 Feb 2022
TL;DR: In this article , a D-band transceiver and a 2D-scalable 2D phased-array module are proposed to overcome the free-space path loss in a flat panel with added capabilities such as self alignment and pole-vibration mitigation.
Abstract: The demand for data across all communication networks continues to grow exponentially. This in turn requires an increase in both capacity and density of backhaul point-to-point (PTP) and point-to-multipoint (PTMP) data links. The D-band frequency range (110 to 170GHz) offers ample spectrum and acceptable propagation characteristics for next generation, high-data-rate backhaul systems [1], [2]. A D-band transceiver (TRX) coupled with a 2D phased-array module can overcome the free-space path loss in a flat panel with added capabilities such as self-alignment and pole-vibration mitigation. Such an FDD system (proposed in Fig. 4.1.1(a)) can also be used in self-organizing networks if deployed in a PTMP configuration. Furthermore, if deployed in a multiple-input-multiple-output (MIMO) setup it can achieve very-high-throughput wireless links reaching data-rates exceeding 100Gb/s [1]. To demonstrate such a system two main components are required: First, a high-performance D-band TRX capable of high-order, wide-bandwidth modulation such as the one presented in [1]. Second, scalable TX/RX phased-array front-end modules with 2D scanning capability. Recently published D-band phased-arrays [2]–[6] have reduced usability as they can only be scaled in one dimension. To overcome this limitation, a 2D-scalable array must be realized without compromising system performance. Hence, at D-band, this demands new interposer materials and compact TX/RX phased-array chipsets. This is a difficult problem with current packaging technologies due to their limited available routing layers [2], [3]. Moreover, at D-band, the physical dimensions of the antennas and their spacing become comparable to the size of the phased-array chipsets or even smaller [2]–[6]. This work addresses and overcomes the above challenges as follows. First, a low-loss, fine-lithography interposer technology with multi-layer routing is utilized. It is based on a glass substrate with two redistribution layers (RDL) providing four metal layers. The glass substrate acts both as the flip-chip site and integration platform for RF distribution networks, waveguide interfaces, antennas, and digital/power routing. The phased-array TX/RX chips are designed to be directly attached to the antenna feed points, thereby minimizing interface losses. 0.7A (140GHz) antenna spacing was chosen in part for backhaul PTP applications with stringent grating lobe yet relaxed scanning requirements. The architecture of the proposed D-band phased-array module is shown in Fig. 4.1.1(b). The module is built by integrating 64 phased-array TX or RX front-end chips each with four channels for a total of 256 active elements. A 1-to-64-way D-band power-combiner/splitter network based on a substrate-integrated-waveguide (SIW) topology is implemented in the glass. Furthermore, a 256-element antenna array (configured as 16×16) is implemented in the same glass substrate. Each TX or RX channel interfaces to the antenna through a via probe with an annular ring slot as depicted in Fig. 4.1.1(c). An H-shaped, cavity-backed slot in combination with the via probe location controls the antenna's 2-pole response, allowing for a wide fractional bandwidth (>13%). Local RF loop-back capability is also implemented on the glass substrate. This consists of four antenna elements placed on the perimeter of the array. They are routed to either a separate TX or RX chip that samples a small part of the radiated signal (in nearfield) and feeds it back to the RF calibration port of the TRX. The feedback path can be used for factory testing, array calibration, digital pre-distortion (DPD) training and fault detection after field deployment.
TL;DR: In this article , two types of phased array metan-tennas are exemplified: planar planar metantenna operating at Ka-band with broadband circularly polarized operation over a wide scanning range and a hybrid architecture of a flat metalens and a circularly polarised phased array at X-band.
Abstract: To optimize the reception and transmission in real-time changing links, phased array antennas have been increasingly investigated and applied in satellite applications. The phased array antenna technology intelligently combines multiple individual antenna elements to improve system performance in terms of gain enhancement, interference cancellation, radiation patterns formation, and radiation beam steering over a wide coverage. This article updates the latest development of metamaterial-based antenna (metantenna) technology in phased array antennas. With metama-terials' unique electromagnetic properties, which have never been found in nature, metantenna technology has been widely used to miniaturize the antenna element, broaden the bandwidth of the array, suppress the inter-element mutual coupling to eliminate scanning blindness, reduce the number of phase shifters, lower side-lobe levels, and so on. Recently, metantennas have been applied in the phased array technology to further boost the performance and reduce the volume and active device cost of the phased arrays in satellite systems. Two types of phased array metan-tennas are exemplified. One is the planar phased array metantenna operating at Ka-band with broadband circularly polarized operation over a wide scanning range. The other one is a hybrid architecture of a flat metalens and a circularly polarized phased array at X-band. The proposed low-profile architecture uses fewer phase shifters to lower the system complexity and cost. With performance enhancement and cost reduction, the phased array metantennas are ready to embrace more promising applications in next-generation satellite and radar systems as well as 5G Advanced and future 6G wireless communication systems.
20 Feb 2022
TL;DR: In this article , the authors proposed mm-wave 5G phased arrays supporting up to 256 elements, which can cover all angles within the scan range, yet their beam tables typically support <300 beams and their increased power consumption may lead to severe thermal challenges.
Abstract: As millimeter-wave (mm-wave) 5G technology adoption expands, it faces growing technical challenges. Among these are the extension of the 28GHz band, to 24.25 to 29.5GHz (n257, n258 and n261 5G NR bands) and the demand for 5G base stations to cover large distances by using a larger number of antenna elements. While mm-wave 5G phased arrays supporting up to 256 elements have been reported [1,5-8], they suffer from two key challenges: (1) their created beams are narrow, requiring thousands of beams to cover all angles within the scan range, yet their beam tables typically support <300 beams [1], [2]; and (2) their increased power consumption may lead to severe thermal challenges, especially in situations where air-cooling cannot be used.
TL;DR: In this article , the authors proposed a phased array (PA) system for mmWave communications, which is defined as a multiple-antenna system that electronically controls the radiated electromagnetic (EM) beam.
Abstract: Millimeter-wave (mm-wave) technology is a viable candidate to address the growing data traffic in 5G wireless communication and beyond. However, challenges related to free-space propagation loss, atmospheric absorption, scattering, and nonline-of-sight propagation must be addressed to benefit from the promised bandwidth available in the mm-wave regime. In this context, phased-array technology is considered vital to provide high-speed and seamless wireless solutions to the industry. A phased array can be defined as a multiple-antenna system that electronically controls the radiated electromagnetic (EM) beam. The official origin of the antenna array concept is attributed to Guglielmo Marconi. A repeated Morse code signal letter “S” from Poldhu, United Kingdom to St. John’s in Canada was successfully demonstrated in December 1901, using a two-element antenna array. In the early 1940s, Luis Walter Alvarez designed the first electronically scanning phased-array radar. Both scientists were awarded the Nobel Prize for their discovery.
TL;DR: In this article , neural probes with integrated optical phased arrays are used for optogenetic stimulation and calcium imaging in brain tissue. But they are not suitable for brain electrophoresis.
Abstract: Implantable silicon neural probes with integrated nanophotonic waveguides can deliver patterned dynamic illumination into brain tissue at depth. Here, we introduce neural probes with integrated optical phased arrays and demonstrate optical beam steering in vitro. Beam formation in brain tissue is simulated and characterized. The probes are used for optogenetic stimulation and calcium imaging.
TL;DR: In this paper , the authors proposed two phased array antennas (PAAs) based on highly conductive graphene-assembled film (GAF) for 5G millimeter wave applications with the advantages of light weight and high thermal conductivity.