Showing papers on "Phased array published in 2012"

Aberration-free ultra-thin flat lenses and axicons at telecom wavelengths based on plasmonic metasurfaces

Abstract: The concept of optical phase discontinuities is applied to the design and demonstration of aberration-free planar lenses and axicons, comprising a phased array of ultrathin subwavelength spaced optical antennas. The lenses and axicons consist of radial distributions of V-shaped nanoantennas that generate respectively spherical wavefronts and non-diffracting Bessel beams at telecom wavelengths. Simulations are also presented to show that our aberration-free designs are applicable to high numerical aperture lenses such as flat microscope objectives.

A 0.28 THz Power-Generation and Beam-Steering Array in CMOS Based on Distributed Active Radiators

Abstract: In this paper, we present a scalable transmitter architecture for power generation and beam-steering at THz frequencies using a centralized frequency reference, sub-harmonic signal distribution, and local phase control. The power generation and radiator core is based on a novel method called distributed active radiation, which enables high conversion efficiency from DC to radiated terahertz power above fmax of a technology. The design evolution of the distributed active radiator (DAR) follows from an inverse design approach, where metal surface currents at different harmonics are formulated in the silicon chip for the desired electromagnetic field profiles. Circuits and passives are then designed conjointly to synthesize and control the surface currents. The DAR consists of a self-oscillating active electromagnetic structure, comprising of two loops which sustain out-of-phase currents at the fundamental frequency and in-phase currents at the second harmonic. The fundamental signal, thus gets, spatially filtered, while the second harmonic is radiated selectively, thereby consolidating signal generation, frequency multiplication, radiation of desired harmonic and filtration of undesired harmonics simultaneously in a small silicon footprint. A two-dimensional 4×4 radiating array implemented in 45 nm SOI CMOS (without high-resistivity substrate) radiates with an EIRP of +9.4 dBm at 0.28 THz and beam-steers in 2D over 80° in both azimuth and elevation. The chip occupies 2.7 mm × 2.7 mm and dissipates 820 mW of DC power. To the best of the authors' knowledge, this is the first reported integrated beam-scanning array at THz frequencies in silicon.

The Planar Ultrawideband Modular Antenna (PUMA) Array

Abstract: A fully planar ultrawideband phased array with wide scan and low cross-polarization performance is introduced. The array is based on Munk's implementation of the current sheet concept, but it employs a novel feeding scheme for the tightly coupled horizontal dipoles that enables simple PCB fabrication. This feeding eliminates the need for “cable organizers” and external baluns, and when combined with dual-offset dual-polarized lattice arrangements the array can be implemented in a modular, tile-based fashion. Simple physical explanations and circuit models are derived to explain the array's operation and guide the design process. The theory and insights are subsequently used to design an exemplary dual-polarized infinite array with 5:1 bandwidth and VSWR <; 2.1 at broadside, and cross-polarization ≈ -15 dB out to θ = 45° in the D- plane.

Novel Approaches to the Design of Phased Array Antennas

Abstract: ii To the most beloved people in my life,

Target Localization and Tracking in Noncoherent Multiple-Input Multiple-Output Radar Systems

Abstract: For a noncoherent multiple-input multiple-output (MIMO) radar system, the maximum likelihood estimator (MLE) of the target location and velocity, as well as the corresponding Cramer-Rao lower bound (CRLB) matrix, is derived. MIMO radar's potential in localization and tracking performance is demonstrated by adopting simple Gaussian pulse waveforms. Due to the short duration of the Gaussian pulses, a very high localization performance can be achieved, even when the matched filter ignores the Doppler effect by matching to zero Doppler shift. This leads to significantly reduced complexities for the matched filter and the MLE. Further, two interactive signal processing and tracking algorithms, based on the Kalman filter and the particle filter (PF), respectively, are proposed for noncoherent MIMO radar target tracking. For a system with a large number of transmit/receive elements and a high signal-to-noise ratio (SNR) value, the Kalman filter (KF) is a good choice; while for a system with a small number of elements and a low SNR value, the PF outperforms the KF significantly. In both methods, the tracker provides predictive information regarding the target location, so that the matched filter can match to the most probable target locations, reducing the complexity of the matched filter and improving the tracking performance. Since tracking is performed without detection, the presented approach can be deemed as a track-before-detect approach. It is demonstrated through simulations that the noncoherent MIMO radar provides significant tracking performance improvement over a monostatic phased array radar with high range and azimuth resolutions. Further, the effects of coherent integration of pulses are investigated for both the phased array radar and a hybrid MIMO radar, where only the pulses transmitted and received by colocated transceivers are coherently integrated and the other pulses are combined noncoherently. It is shown that the hybrid MIMO radar achieves significant tracking performance improvement when compared with the phased array radar, by using the extra Doppler information obtained through coherent pulse integration.

Applying full polarization A-Projection to very wide field of view instruments: An imager for LOFAR

Abstract: The aimed high sensitivities and large fields of view of the new generation of interferometers impose to reach high dynamic range of order $\sim$1:$10^6$ to 1:$10^8$ in the case of the Square Kilometer Array. The main problem is the calibration and correction of the Direction Dependent Effects (DDE) that can affect the electro-magnetic field (antenna beams, ionosphere, Faraday rotation, etc.). As shown earlier the A-Projection is a fast and accurate algorithm that can potentially correct for any given DDE in the imaging step. With its very wide field of view, low operating frequency ($\sim30-250$ MHz), long baselines, and complex station-dependent beam patterns, the Low Frequency Array (LOFAR) is certainly the most complex SKA precursor. In this paper we present a few implementations of A-Projection applied to LOFAR that can deal with non-unitary station beams and non-diagonal Mueller matrices. The algorithm is designed to correct for all the DDE, including individual antenna, projection of the dipoles on the sky, beam forming and ionospheric effects. We describe a few important algorithmic optimizations related to LOFAR's architecture allowing us to build a fast imager. Based on simulated datasets we show that A-Projection can give dramatic dynamic range improvement for both phased array beams and ionospheric effects. We will use this algorithm for the construction of the deepest extragalactic surveys, comprising hundreds of days of integration.

60-GHz Four-Element Phased-Array Transmit/Receive System-in-Package Using Phase Compensation Techniques in 65-nm Flip-Chip CMOS Process

Abstract: AThe 60-GHz four-element phased-array transmit/receive (TX/RX) system-in-package antenna modules with phase-compensated techniques in 65-nm CMOS technology are presented. The design is based on the all-RF architecture with 4-bit RF switched LC phase shifters, phase compensated variable gain amplifier (VGA), 4:1 Wilkinson power combining/dividing network, variable-gain low-noise amplifier, power amplifier, 6-bit unary digital-to-analog converter, bias circuit, electrostatic discharge protection, and digital control interface (DCI). The 2 × 2 TX/RX phased arrays have been packaged with four antennas in low-temperature co-fired ceramic modules through flip-chip bonding and underfill process, and phased-array beam steering have been demonstrated. The entire beam-steering functions are digitally controllable, and individual registers are integrated at each front-end to enable beam steering through the DCI. The four-element TX array results in an output of 5 dBm per channel. The four-element RX array results in an average gain of 25 dB per channel. The four-element array consumes 400 mW in TX and 180 mW in RX and occupies an area of 3.74 mm2 in the TX integrated circuit (IC) and 4.18 mm2 in the RX IC. The beam-steering measurement results show acceptable agreement of the synthesized and measured array pattern.

A CMOS bidirectional 32-element phased-array transceiver at 60GHz with LTCC antenna

Abstract: An integrated CMOS 60 GHz phased-array antenna module supporting symmetrical 32 TX/RX elements for wireless docking is described. Bidirectional architecture with shared blocks, mm-wave TR switch design with less than 1dB TX loss, and a full built in self test (BIST) circuits with 5deg and +/−1dB measurement accuracy of phase and power are presented. The RFIC size is 29mm2, consuming 1.2W/0.85W at TX and RX with a 29dBm EIRP at −19dB EVM and 10dB NF.

Mid-infrared virtually imaged phased array spectrometer for rapid and broadband trace gas detection

Abstract: We present and characterize a two-dimensional (2D) imaging spectrometer based on a virtually imaged phased array (VIPA) disperser for rapid, high-resolution molecular detection using mid-infrared (MIR) frequency combs at 3.1 and 3.8 μm. We demonstrate detection of CH4 at 3.1 μm with >3750 resolution elements spanning >80 nm with ∼600 MHz resolution in a <10 μs acquisition time. In addition to broadband detection, we also demonstrate rapid, time-resolved single-image detection by capturing dynamic concentration changes of CH4 at a rate of ∼375 frames per second. Changes in absorption above the noise floor of 5×10−4 are readily detected on the millisecond time scale, leading to important future applications such as real-time monitoring of trace gas concentrations and detection of reactive intermediates.

W-Band Silicon-Based Frequency Synthesizers Using Injection-Locked and Harmonic Triplers

Abstract: Two monolithically integrated W-band frequency synthesizers are presented Implemented in a 018 μm SiGe BiCMOS with fT/fmax of 200/180 GHz, both circuits incorporate the same 303-338 GHz PLL core One synthesizer uses an injection-locked frequency tripler (ILFT) with locking range of 928-981 GHz and the other employs a harmonic-based frequency tripler (HBFT) with 3-dB bandwidth of 105 GHz from 909-1014 GHz, respectively The measured RMS phase noise for ILFT- and HBFT-based synthesizers are 54° and 55° (100 kHz to 100 MHz integration), while phase noise at 1 MHz offset is -93 and -92 dBc/Hz, respectively, at 96 GHz from a reference frequency of 125 MHz The measured reference spurs are <; -52 dBc for both prototypes The combined power consumption from 18- and 25-V is 140 mW for both chips The frequency synthesizer is suitable for integration in millimeter-wave (mm-wave) phased array and multi-pixel systems such as W-band radar/imaging and 120 GHz wireless communication

A 2-D Electronically Steered Phased-Array Antenna With 2 $\,\times\,$ 2 Elements in LC Display Technology

Abstract: For the first time, a 2-D electronically steered phased-array antenna with a liquid-crystal (LC)-based variable delay line is presented. The structure, which is designed at 17.5 GHz, consists of a 2 × 2 microstrip patch antenna array, continuously variable delay lines with a novel geometry, RF feeding, and biasing networks. The expected insertion loss of the variable delay line is less than 4 dB with a maximum differential phase shift of 300°. During the measurements, the antenna is steered by applying an appropriate dc biasing in the range of 0-15 V to the variable delay lines. It is also shown that the return loss is always better than 15 dB at the operating frequency when the antenna is steered.

A Two-Channel Time Modulated Linear Array With Adaptive Beamforming

Abstract: A Time modulated linear array (TMLA) can be configured to perform many of the functions of phased array antennas but at much lower cost as they do not require phase shifters. However, conventional time modulated linear arrays which are configured for beam steering based on a single output channel topology. Such a topology is inefficient in terms of time utilization of the array elements. In this contribution we have proposed a multiple output channels time modulated linear array which exploits the time redundancy of conventional systems. The concept is introduced by considering conventional harmonic beam steering and then extending the problem to two-channel adaptive beamforming.

A 76 GHz Multi-Layered Phased Array Antenna Using a Non-Metal Contact Metamaterial Waveguide

Abstract: A 76 GHz phased array antenna (PAA) using waffle-iron ridge waveguides with non-metal contacts has been developed. The non-metal contact technology has the advantage of avoiding losses due to imperfect metal contacts, and also facilitates the fabrication of small-size and multi-layer stacked structures. The principle and results of the developed phase shifter, radiator and feed network are presented. For the feed network, it is shown that the phase differences between adjacent radiators are the same, which confirms the validity of the fundamental operation of the PAA. A PAA combining the feed network and 16 radiators with a size of 62 mm × 62 mm × 25 mm was realized. The characteristic of the PAA was evaluated by calculating the directivity using measured data from the radiator and the feed network. From these considerations, the PAA was found to have the capability of providing a beam tilt angle of ±18° while maintaining a gain of more than 32 dBi.

Spaceborne Reflector SAR Systems with Digital Beamforming

Abstract: Spaceborne synthetic aperture radar (SAR) imaging enters an era where increasingly short revisit times, or large swath widths, respectively, and high spatial resolutions are requested. These requirements impose contradicting constraints on conventional SAR systems using analog beamforming technology. The development for future radar satellites is therefore towards digital beamforming (DBF) systems where the analogous receiver hardware is replaced by digital components. Concerning the SAR antenna the innovative concept of a parabolic mesh reflector in conjunction with a digital feed array is becoming a promising architecture for this new SAR system generation. These antennas, already a mature technique for communication satellites, have the potential to outperform planar array antennas in terms of gain at a moderate hardware effort. This article provides a hardware concept study based on a design in X-band. Focus is put on DBF algorithms adopted to the SAR case and important performance figures are derived.

A 76–84 GHz 16-element phased array receiver with a chip-level built-in-self-test system

Abstract: A 16-element phased array receiver with built-in-self test (BIST) is demonstrated at 76–84 GHz. The BIST technique employs a miniature capacitive coupler located at the input port of each phased-array channel, and uses the receiver I/Q down-converter to measure the amplitude and phase of each channel. This allows for measuring the response of individual channels if one channel is turned on at a time, and an on-chip array factor if several channels are turned on and the phase between them is varied. BIST measurements done at 76–84 GHz agree very well with S-parameter measurements with a matched load and an open circuit load at each port, and show that this technique can be used to greatly lower the testing cost and improve the self-calibration of mm-wave phased-array RFICs.

MAARSY: The new MST radar on Andøya—System description and first results

Abstract: [1] The Middle Atmosphere Alomar Radar System (MAARSY) on the North-Norwegian island Andoya is a 535 MHz monostatic radar with an active phased array antenna consisting of 433 Yagi antennas The 3-element Yagi antennas are arranged in an equilateral triangle grid forming a circular aperture of approximately 6300 m2 Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output up to 2 kW This arrangement provides a very high flexibility of beam forming and beam steering with a symmetric radar beam of a minimum beam width of 36° allowing classical beam swinging operation as well as experiments with simultaneous multiple beams and the use of interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatio-temporal resolution The installation of the antenna array was completed in August 2009 The radar control and data acquisition hardware as well as an initial expansion stage of 196 transceiver modules was installed in spring 2010 and upgraded to 343 transceiver modules in November 2010 The final extension to 433 transceiver modules has recently been completed in May 2011 Beside standard observations of tropospheric winds and Polar Mesosphere Summer Echoes, the first multi-beam experiments using up to 97 quasi-simultaneous beams in the mesosphere have been carried out in 2010 and 2011 These results provide a first insight into the horizontal variability of polar mesosphere summer and winter echoes with time resolutions between 3 and 9 minutes In addition, first meteor head echo observations were conducted during the Geminid meteor shower in December 2010

Electronically steerable planar phased array antenna

Abstract: A two-dimensional (2-D) beam steerable phased array antenna is presented comprising a continuously electronically steerable material including a tunable material or a variable dielectric material, preferred a liquid crystal material. A compact antenna architecture including a patch antenna array, tunable phase shifters, a feed network and a bias network is proposed. Similar to the LC display, the proposed antenna is fabricated by using automated manufacturing techniques and therefore the fabrication costs are reduced considerably.

A 60-GHz Active Receiving Switched-Beam Antenna Array With Integrated Butler Matrix and GaAs Amplifiers

Abstract: This paper presents for the first time a 60-GHz receiving switched-beam antenna on organic liquid crystal polymer (LCP) platform. A 4 × 1 quasi-Yagi array is incorporated with a 4 × 4 Butler matrix beamforming network and GaAs low-noise amplifiers on an LCP substrate. The active beam is controlled by GaAs single-pole-double-throw switches to access the four output states of the Butler matrix. The entire 4 × 1 active array is 1.4 cm × 1.75 cm and consumes 1.1 W of dc power. Successful comparisons of the measured and simulated results verify a working phased array with a return loss better than 10 dB across the frequency band of 56.7-63.7 GHz. A comparison of radiation patterns demonstrate beam steering of ±40° with a peak active gain of 27.5 dB. The combined antenna and receiver noise performance at 60 GHz exhibits an estimated merit G/T of -18.6 dB/K and noise figure of 5.4 dB.

Ka-Band Phased Array Antenna for High-Data-Rate SATCOM

Abstract: The general issue of this letter deals with the design of a phased array antenna for high-data-rate SATCOM. A final demonstrator antenna could be installed on an unmanned aerial vehicle (UAV) to communicate with a satellite in Ka-band. First, a compact reflection-type phase shifter is designed and realized. Second, the conception of a phased array antenna prototype is detailed. Third, a new calibration method is involved that can provide the bias voltage to be applied to each phase shifter in order to scan the beam in the desired direction.

A 44–46-GHz 16-Element SiGe BiCMOS High-Linearity Transmit/Receive Phased Array

Abstract: This paper presents a 16-element Q-band transmit/ receive phased array with high receive linearity and low power consumption The design is based on the all-RF architecture with passive phase shifters and a 1:16 Wilkinson network An input P1dB from -9 to -10 dBm and a noise figure of 10-115 dB at 44-46 GHz is achieved in the receive mode with a power consumption of 095 W In the transmit mode, each channel has an output P1dB of 3-2 dBm and Psat of 6-4 dBm at 44-46 GHz with a power consumption of 116 W The design results in a low root mean square (rms) gain error due to a high-resolution variable gain amplifier in each channel Measurements on multiple channels show near-identical gain and phase response in both the transmit and receive mode due to the use of a symmetrical passive combiner The measured on-chip coupling is <; -40 dB and results in insignificant additional rms and phase error

Integration of Array Antennas in Chip Package for 60-GHz Radios

Abstract: This paper discusses the integration of array antennas in chip packages for highly integrated 60-GHz radios. First, we evaluate fixed-beam array antennas, showing that most of them suffer from feed network complexity and require sophisticated process techniques to achieve enhanced performance. We describe the grid array antenna and show that is a good choice for fixed-beam array antenna applications due to its easy feed network design and manufacture. Then, we examine switched-beam array antennas using the Rotman lens or Butter matrix, illustrating that they allow scanning only in one plane and some miss a link even in the boresight direction. Nevertheless, a switched-beam array antenna uses a conceptually simple switch circuit to select the best signal path and may be a cost-effective approach to implementing steerable antennas in the 60-GHz band. Finally, we describe adaptive beam or phased array antennas and highlight the challenges and practical realizations of phased array antennas in both ceramic and organic chip packages for single-chip 60-GHz radios.

Investigation of Standing-Wave Formation in a Human Skull for a Clinical Prototype of a Large-Aperture, Transcranial MR-Guided Focused Ultrasound (MRgFUS) Phased Array: An Experimental and Simulation Study

Abstract: Standing-wave formation in an ex vivo human skull was investigated using a clinical prototype of a 30-cm diameter with 15-cm radius of curvature, low-frequency (230 kHz), hemispherical transcranial magnetic resonance-guided focused ultrasound phased array. Experimental and simulation studies were conducted with changing aperture size and f -number configurations of the phased array and qualitatively and quantitatively examined the acoustic pressure variation at the focus due to standing waves. The results demonstrated that the nodes and antinodes of standing wave produced by the small-aperture array were clearly seen at approximately every 3 mm. The effect of the standing wave became more pronounced as the focus was moved closer to skull base. However, a sharp focus was seen for the full array, and there was no such standing-wave pattern in the acoustic plane or near the skull base. This study showed that the fluctuation pressure amplitude would be greatly reduced by using a large-scale, hemispherical phased array with a low f-number.

Hybrid III/V silicon photonic source with integrated 1D free-space beam steering

Abstract: A chip-scale optical source with integrated beam steering is demonstrated. The chip was fabricated using the hybrid silicon platform and incorporates an on-chip laser, waveguide splitter, amplifiers, phase modulators, and surface gratings to comprise an optical phased array with beam steering across a 12° field of view in one axis. Tuning of the phased array is used to achieve 1.8°(steered axis)×0.6°(nonsteered axis) beam width with 7 dB background suppression for arbitrary beam direction within the field of view.

A Low-Power BiCMOS 4-Element Phased Array Receiver for 76–84 GHz Radars and Communication Systems

Abstract: This paper presents a 76-84 GHz low-power 4- element phased array receiver built using a 0.13 μm BiCMOS process. The power consumption is reduced by using a single-ended design and alternating the amplifiers and phase shifter cells to result in a low noise figure at a low power consumption. A variable gain amplifier and an 11° trim bit are used to correct for the rms gain and phase errors at different operating frequencies. The phased array consumes 32 mW per channel and results in a gain of 10-19 dB at 76-84 GHz, a noise figure of 10.5 ±0.5 dB at 80 GHz and an rms gain and phase error <;0.8 dB and <;7.2 °, respectively, up to 81 GHz, and <;1.1 dB and 10.4° up to 84 GHz. The phased array also shows a channel to channel coupling of <; - 30 dB up to 84 GHz. To our knowledge, this work presents state-of-the-art on-chip performance at W-band frequencies.

Lab on a chip phased-array MR multi-platform analysis system

Abstract: We present a lab on a chip (LOC) compatible modular platform for magnetic resonance (MR)-based investigation of sub-millimetre samples. The platform combines the advantages offered respectively by microcoils (high resolution at the microscale) and macroscopic surface coils (large field of view) as MR-detectors and consists of a phased array of microcoils (PAMs) providing a flat MR-sensitive area of 18.3 mm2 with a B0-field uniformity better than 0.25 ppm in the sensor centre area. We demonstrate both high-resolution magnetic resonance imaging (MRI) and NMR spectroscopy using this platform. To demonstrate the application for biological samples, we report MR imaging of fish oocytes with an in-plane resolution of 30 × 30 μm2 and a contrast to noise ratio of 10 for a scan time of only 13 min 39 s. We have also demonstrated high-resolution spectroscopy of a water phantom achieving 11 ppb (4.5 Hz at 400 MHz) linewidth and an SNR of 28 for only 12 s scan time. State of the art automatic wire bonding technology in conjunction with MEMS techniques has been employed to manufacture the platform with potential applications in MR-investigation of planar samples.

Phase Only Antenna Pattern Notching Via a Semidefinite Programming Relaxation

Abstract: A phase-only method of generating notches in the beam pattern of a phased array antenna is described. It is shown how the problem can be formulated as a semidefinite programming problem, and solved with readily available solvers. Numerical results simulating the performance of a 32 element uniform linear array are presented.

A 4-Path 42.8-to-49.5 GHz LO Generation With Automatic Phase Tuning for 60 GHz Phased-Array Receivers

Abstract: This paper presents a 4-path LO generation system with automatic phase tuning for 60 GHz phased-array receivers. Each path employs a linear phase-shift generation chain composed of an injection-locked-oscillator-based phase shifter cascaded with an injection-locked frequency tripler. The frequency tripler with a proposed locking-range enhancement technique is employed to relax both the frequency and the phase shift of the phase shifter for high linearity and low power. Finally, a novel successive-approximation algorithm is proposed to perform automatic phase detection and tuning. Fabricated in a 65 nm CMOS process and occupying a core area of 1.4 ×2.0 mm2, the proposed 4-path LO generation system measures linear phase shift range larger than ±90°, amplitude variation within ±0.4 dB, phase resolution of 22.5°, and maximum phase errors of 22.0° and 1.5° before and after automatic phase calibration while drawing a current of 85 mA from a 1-V supply.

Scanning non-scanning LIDAR

Abstract: An all fiber optic laser based scanning system for real time terrain mapping under degraded visual conditions is disclosed. A laser output is modulated to achieve a desired pulse width and pulse repetition frequency (PRF) and the modulated signal is amplified. The amplified optical signals are split into N channels that correspond to N elements of an optically phased array that steers light by modulating the phase of light entering and exiting the optical system. By applying a linear phase shift across the beam's wave front, the light propagating along the system's optical axis is steered to an off-axis angle. A real time map of an underlying terrain is accomplished by sweeping the N channel array across the terrain while collecting range information from each scan grid.

A Fully Integrated 0.18- $\mu{\hbox {m}}$ CMOS Transceiver Chip for $X$ -Band Phased-Array Systems

Abstract: An X-band core chip is designed and fabricated in 0.18- CMOS technology, which can significantly reduce the monolithic microwave integrated circuit count required for realizing an active beam-former T/R module. The core chip consists of two RX/TX paths, each of which includes a 6-b phase shifter, a 6-b attenuator, along with two input and output amplifiers. A new architecture for realizing such a core chip system and a low loss circuit for 5.625° phase shift block are proposed. The overall rms phase and gain errors are better than 2° and 0.25 dB, respectively, in both RX/TX paths. The gain of each path is around 12 dB, while the output 1-dB compression point is higher than 10 dBm over the band of interest.