Showing papers on "Phased array published in 2011"

Two-dimensional free-space beam steering with an optical phased array on silicon-on-insulator

Abstract: We demonstrate a 16-channel, independently tuned waveguide surface grating optical phased array in silicon for two dimensional beam steering with a total field of view of 20° x 14°, beam width of 0.6° x 1.6°, and full-window background peak suppression of 10 dB.

A 60GHz CMOS phased-array transceiver pair for multi-Gb/s wireless communications

Abstract: Recent advances in silicon technology, mm-Wave integrated circuit/antenna/package design, and beam-forming techniques at 60GHz, together with the emergence of suitable wireless standards, have enabled consumer electronics products to support wireless transmission of multi-Gb/s data such as high-definition (HD) audio/video content [1,2]. Further expansion into portable and mobile platforms will require lower power consumption, smaller form factor, and lower cost. This paper describes a fully integrated, low-cost 60GHz phased-array transceiver pair, implemented in 65nm standard digital CMOS and packaged with an embedded antenna array, capable of robust 10m non-line of sight (NLOS) communication. The array is configurable from 32 elements to 8 or fewer elements, making the transceiver pair suitable for both fixed, high-data-rate and portable, low-power applications. To enhance the robustness of the multi-element design, dynamic phase shifters allow the beam direction to be changed in real time to adapt to changing environments without interruption of the multi-Gb/s data stream. The transceiver pair supports the WirelessHD and draft 802.11ad (WiGig) standards at maximum data rates of 7.14Gb/s and 6.76Gb/s, respectively.

60-GHz Electronically Reconfigurable Large Reflectarray Using Single-Bit Phase Shifters

Abstract: A large electronically reconfigurable reflectarray antenna that has 160 × 160 reflecting elements was designed, fabricated, and evaluated so that it could be applied to a millimeter-wave imaging system operating in the 60-GHz band. To make it feasible to construct such a large reflectarray, the reflecting element structure had to be simple and easily controlled; therefore, a reflecting element consisting of a microstrip patch and a single-bit digital phase shifter using a p-i-n diode was employed. A large reflectarray antenna was fabricated using the reflecting elements. The measured radiation patterns and antenna gain were in good agreement with those that were calculated. Furthermore, the near-field beam focusing capabilities, which was required to image near-field objects, were also verified through an experiment. Finally, the response time for beamforming was measured, which was far less than the system requirements.

Harmonic Beamforming in Time-Modulated Linear Arrays

Abstract: In this paper, the synthesis of simultaneous multibeams through time-modulated linear arrays is studied. Unlike classical phased arrays where the antenna aperture is usually shared to generate multiple beams, the periodic on-off sequences controlling the static excitations are properly defined by means of an optimization strategy based on the Particle Swarm algorithm to afford desired multiple patterns at harmonic frequencies to make practical application of these harmonic beams which are typically regarded as an undesirable effect in time-modulated arrays. The synthesis of simultaneous broadside sum and difference patterns, flat-top and narrow beam patterns, and steered multibeams is enabled as assessed by a set of selected results reported and discussed to show the potentialities of the proposed method. Comparisons with previously published results are reported, as well.

Mm-wave phased array antenna and system integration on semi-flex packaging

Abstract: 60GHz technology utilizes world wide exempt 5–9GHz bandwidth to provide multi-gigabit high throughput wireless communication in WPAN and WLAN applications. One of the key challenges to enable 60GHz technology is developing mm-wave phased array antenna design and packaging integration with mm-wave ICs. This paper presents a conformal mm-wave phased array antenna design and packaging integration to provide low loss solution and flexibility for platform integration.

Mm-wave phased array antenna with beam tilting radiation pattern

Abstract: A system according to one embodiment includes a phased array antenna comprising a plurality of antenna elements, the plurality of antenna elements configured in a planar array, wherein each of the plurality of antenna elements generates a beam pattern directed at an angle out of the plane of the planar array; and driver circuitry coupled to each of the plurality of antenna elements, wherein the driver circuitry comprises a plurality of transceivers, the plurality of transceivers configured to provide independently adjustable phase delay to each of the plurality of antenna elements.

Wide-Angle Scanning Phased Array With Pattern Reconfigurable Elements

Abstract: A novel phased array is presented to extend array scanning range by using pattern reconfigurable antenna elements and weighted thinned synthesis technology in this paper. The pattern reconfigurable microstrip Yagi antenna element is used as a basic element in array and it is capable of reconfiguring its patterns from broadside to quasi-endfire radiation by shifting states of the PIN diode switches integrated on parasitic strips. A weighted thinned linear array synthesis technique is analyzed and some interesting conclusions have been made. A linear array composed of eight pattern reconfigurable antenna elements is manufactured to demonstrate the excellent performance of the array. The active element pattern of each element is measured and pre-stored. Based on active element patterns and weighted thinned linear array synthesis technique, the pattern scanning performance of the novel array is synthesized. The results indicate that the array can scan its main beam from φ = -60° to φ = 60° in H-plane with gain fluctuation less than 3 dB while maintaining low side lobes, and the -3 dB beam width coverage is about from φ = -68° to φ = 68°. The performance is superior to the traditional phased array made of wide-beam elements.

Vertically integrated phased array

Abstract: A vertically integrated electronically steered phased array that employs beamsteering using a programmable phase locked loop including a local oscillator. The local oscillator provides an oscillator signal that is converted to an RF signal that can be either up-converted for a transmit operation or down-converted for a receive operation. The relative off-set between independently generated local oscillator signals forms the basis of the off-set phase required for a phased array. The absolute measure of off-set phase is referenced to a globally distributed clock signal that aligns the zero degree phase shift of the oscillator.

Wide Beam Tapered Slot Antenna for Wide Angle Scanning Phased Array Antenna

Abstract: Design and development of a low proflle, compact, wide beam and wide band printed double layered exponentially tapered slot antenna (DTSA) with a coplanar waveguide (CPW) feed meant for wide scan active phased array antenna in X-band has been presented. DTSA satisfles the requirements on the maximum re∞ection coe-cient of i • i10dB for §60 - and §45 - scan from broadside in H- and E- planes, respectively with a moderate gain of 4{7dBi. Realized antenna has shown a symmetric pattern together with moderately high gain, low cross-polarization and 3dB beam width better than §60 - and §45 - in H- and E- planes, respectively. The designed structure is expected to flnd applications in mounting platforms with limited RF real estate available to it like in military aircrafts, owing to its easy integration with the uni-planar monolithic millimeter-wave integrated circuits.

A 65nm CMOS 4-element Sub-34mW/element 60GHz phased-array transceiver

Abstract: The 60GHz band has received significant attention as an enabler for multi-Gb/s wireless communication. Practical mm-Wave systems will require relatively large phased arrays in order to robustly overcome path-loss and fading issues. Despite significant progress [1,2], CMOS implementations of 60GHz phased arrays have so far been area and power hungry. This paper therefore presents a 60GHz 4-element 65nm CMOS phased-array transceiver consuming <34mW/element (including LO synthesis and distribution) that utilizes baseband (BB) phase shifting and holistic impedance optimization.

Phased-array antenna aiming method and device and phased-array antenna

Abstract: A method and an apparatus for aligning a phased array antenna, and a phased array antenna are provided. A method for aligning a phased array antenna according to an embodiment of the present invention includes: receiving signals from respective antenna array subunits; performing phase shifting on the signals from the respective antenna array subunits, combining phase-shifted signals, where the signals are from the respective antenna array subunits, and obtaining a first signal, where a receiving beam corresponding to the first signal is a rotating receiving beam; rotating, by the rotating receiving beam, around a transmitting/receiving beam according to a preset angular frequency by using the transmitting/receiving beam as a rotation axis; calculating power values of respective first signals in a case that the rotating receiving beam rotates through different angles; and adjusting, according to the power values, a direction of the transmitting/receiving beam to align a phased array antenna.

A 65 nm CMOS 4-Element Sub-34 mW/Element 60 GHz Phased-Array Transceiver

Abstract: This paper describes a low power and element-scalable 60 GHz 4-element phased array transceiver implemented in a standard 65 nm CMOS process. Using a 1.2 V supply, the array consumes <;34 mW/element including LO synthesis and distribution. Energy and area efficiency are achieved by utilizing a baseband phase shifting architecture, holistic impedance optimization, and lumped-element based design. Each receiver (RX) element provides 24 dB of gain with an average noise figure (NF) of 6.8 dB while the total saturated output power of the transmitter (TX) is 4.5 dBm. The array achieves 360° of phase shifting range with a worst-case measured phase resolution of 6 bits (TX)/ 5 bits (RX) while maintaining amplitude variations less than ±0.5 dB.

An Optimal Beamforming Strategy for Wide-Field Surveys With Phased-Array-Fed Reflector Antennas

Abstract: An optimal beamforming strategy is proposed for performing large-field surveys with dual-polarized phased-array-fed reflector antennas. This strategy uses signal-processing algorithms that maximize the beam sensitivity and the continuity of a field of view (FOV) that is formed by multiple closely overlapping beams. A mathematical framework and a newly developed numerical approach are described to analyze and optimize a phased array feed (PAF) system. The modeling approach has been applied to an experimental PAF system (APERTIF prototype) that is installed on the Westerbork Synthesis Radio Telescope. The resulting beam shapes, sensitivity, and polarization diversity characteristics (such as the beam orthogonality and the intrinsic cross-polarization ratio) are examined over a large FOV and frequency bandwidth. We consider weighting schemes to achieve a conjugate-field matched situation (max. received power), maximum signal-to-noise ratio (SNR), and a reduced SNR scenario but with constraints on the beam shape. The latter improves the rotational symmetry of the beam and reduces the sensitivity ripple, at a modest maximum sensitivity penalty. The obtained numerical results demonstrate a very good agreement with the measurements performed at the telescope.

EMBRACE: A Multi-Beam 20,000-Element Radio Astronomical Phased Array Antenna Demonstrator

Abstract: We present the design and development of the electronic multi-beam radio astronomy concept (EMBRACE), a demonstrator that is part of the European contribution towards the square kilometre array, which is currently being designed by the global radio astronomical community. One of the design goals of EMBRACE is to demonstrate the applicability of phased array technology for use in future radio telescopes. The EMBRACE system will ultimately consist of two stations, the largest of which comprises over 20,000 elements and has a physical area of about 160 m2 . The antenna system, covering the 500-1500 MHz frequency range, is designed as a dual polarized system, however only the signals for one polarization are processed. To obtain a cost effective design, RF analog beam-forming is performed on tile level close to the radiators. The demonstrator is designed to provide two independent beams such that different parts of the sky can be observed simultaneously. First results from part of the array are presented and discussed. The results show that the complete data path is functional. Since the design resembles a large regular contiguous array, all coupling can be taken into account in the embedded element patterns. The array factor therefore suffices to describe the scanning of the array reducing significantly calibration complexity compared to, e.g. sparse, random or more irregular arrays. This is confirmed by the first array factor measurements, that were done using a novel technique that does not require calibration of the array. The first measurements on an astronomical source, the Sun, indicate that the system noise temperature lies between 104 and 118 K, which is reassuringly close to the design target of 100 K.

Methods and apparatus for volumetric coverage with image beam super-elements

Abstract: Methods and apparatus for a super-element assembly for a phased array radar aperture, the super-element assembly having a first port and a second port to receive a first signal at the first port to generate a main beam, and receive a second signal at the second port to generate an image beam for generating scan volume coverage using the main and image beams.

LTCC Packages With Embedded Phased-Array Antennas for 60 GHz Communications

Abstract: A low-cost, fully-integrated antenna-in-package solution for 60 GHz phased-array systems is demonstrated. Sixteen patch antennas are integrated into a 28 mm × 28 mm ball grid array together with a flip-chip attached transmitter or receiver IC. The packages have been implemented using low temperature co-fired ceramic technology. 60 GHz interconnects, including flip-chip transitions and via structures, are optimized using full-wave simulation. Anechoic chamber measurement has shown ~ 5 dBi unit antenna gain across all four IEEE 802.15.3c channels, achieving excellent model-to-hardware correlation. The packaged transmitter and receiver ICs, mounted on evaluation boards, have demonstrated beam-steered, non-line-of-sight links with data rates up to 5.3 Gb/s.

Design of a Near-Field Focused Reflectarray Antenna for 2.4 GHz RFID Reader Applications

Abstract: The design of a reflectarray antenna is presented when the radiated field is focused in the near-zone of the array aperture. In particular, the reflectarray antenna is implemented for RFID reader applications at 2.4 GHz. Numerical investigations on the radiation characteristics of this reflectarray, as well as an experimental validation, are presented to demonstrate its feasibility.

Two-Dimensional Dispersive Off-Chip Beam Scanner Fabricated on Silicon-On-Insulator

Abstract: One of the key elements in optical wireless applications such as laser scanning and writing is beam steering. While beam steering can be done actively using mirrors or liquid crystals, we have taken a passive approach to steer a beam in two dimensions by wavelength tuning. Therefore, we have fabricated an integrated two-dimensional beam steerer using silicon-on-insulator. The beam width is around 4.0° and can be steered in a range of 15°×50° for a wavelength shift of 100 nm. The beam width and range can be further optimized by changing the grating structure and size of the component.

Method and apparatus for directional proxmity detection

Abstract: A method and apparatus to facilitate directional proximity detection by a wireless device. In one embodiment of the invention, the wireless device has a phased array antenna system that facilitates the directional detection of other wireless device(s). For example, in one embodiment of the invention, the phased array antenna system of the wireless device uses a radiation pattern beam that circumrotates the wireless device to detect the proximity and location of other wireless devices. In another example, in one embodiment of the invention, the wireless device uses a search strategy to optimize the process to detect the proximity and location of other wireless devices. The search strategy may adjust the radiation pattern beam to any desired angle to detect the proximity and location of other wireless devices.

Organic Packages With Embedded Phased-Array Antennas for 60-GHz Wireless Chipsets

Abstract: A multilayer organic package with embedded 60-GHz antennas and fully integrated with a 60-GHz phased-array transmitter or receiver chip is demonstrated. The package includes sixteen phased-array antennas, an open cavity for housing the flip-chip attached RF chip, and interconnects operating at DC-66 GHz. The 28 mm 28 mm ball grid array package is manufactured using printed circuit board processes and uses a combination of liquid-crystal polymer and glass-reinforced laminates, allowing excellent 60-GHz interconnect and antenna performance. The measured return loss and gain of each antenna from 56 to 66 GHz are and , respectively. Finally, the packaged transmitter and receiver chipsets, each working with a heat sink, have demonstrated beam-steered, non-line-of-sight links with data rates up to 5.3 Gb/s using 16-quadrature amplitude modulation single-carrier and orthogonal frequency division multiplexing schemes.

ICE decoupling technique for RF coil array designs

Abstract: Purpose: Parallel magnetic resonance imaging (MRI) requires an array of RF coil elements with different sensitivity distributions and with minimal electromagnetic coupling. The goal of this project was to develop a new method based on induced current compensation or elimination (ICE) for improved coil element decoupling and to investigate its performance in phantom MR images. Methods: An electromagnetic decoupling method based on induced current compensation or elimination for nonoverlapping RF coil arrays was developed with the design criteria of high efficiency, easy implementation, and no physical connection to RF array elements. An eigenvalue/eigenvector approach was employed to analyze the decoupling mechanism and condition. A two-channel microstrip array and an eight-channel coil array were built to test the performance of the method. Following workbench tests, MR imaging experiments were performed on a 7T MR scanner. Results: The bench tests showed that both arrays achieved sufficient decoupling with a S21 less than −25 dB among the coil elements at 298 MHz. The MR phantom images demonstrated well-defined sensitivity distributions from each coil element and the unique decoupling capability of the proposed ICE decoupling technique. B1 distributions of the individual elements were also measured and calculated. Conclusions: The theoretical analysis and experiments demonstrated the feasibility of the decoupling method for high field RF coil array designs without overlapping or direct physical connections between coil elements, which provide more flexibility for coil array design and optimization. The method offers a new approach to address the RF array decoupling issue, which is a major challenge in implementing parallel imaging.

Bistatic Forward-Looking SAR: Results of a Spaceborne–Airborne Experiment

Abstract: Forward-looking radar imaging continues to gain in significance due to a variety of convenient applications, like landing assistance for aircraft in poor visibility conditions. Synthetic aperture radar (SAR) techniques are typically used to achieve a high azimuth resolution, but conventional monostatic SAR is not applicable in forward direction because of azimuth ambiguities and poor Doppler resolution. To improve the Doppler resolution and to avoid azimuth ambiguities, bistatic SAR configurations can be used to obtain high-resolution radar images. This is demonstrated for the first time in a spaceborne-airborne SAR experiment by using TerraSAR-X as the illuminator and the Phased Array Multifunctional Imaging Radar as the receiver. For convenience, the receiver's SAR antenna was mounted on the aircraft's loading ramp and looked backward. Due to identical image properties and the same challenges for forward- and backward-looking sensors, this configuration also demonstrates the feasibility of forward-looking bistatic SAR. This letter describes the experimental setup, analyzes the performance, and presents the imaging results.

Polarimetric Phased-Array Radar for Weather Measurement: A Planar or Cylindrical Configuration?

Abstract: This paper suggests a cylindrical configuration for agile beam polarimetric phased-array radar (PPAR) for weather surveillance. The most often used array configuration for PAR is a planar array antenna. The planar configuration, however, has significant deficiencies for polarimetric measurements, as well as other limitations, such as increases in beamwidth, decreases of sensitivity, and changes in the polarization basis when the beam scans off its broadside. The cylindrical polarimetric phased-array radar (CPPAR) is proposed to avoid these deficiencies. The CPPAR principle and potential performance are demonstrated through theoretical analysis and simulation. It is shown that the CPPAR has the advantage of a scan-invariant polarization basis, and thus avoids the inherent limitations of the planar PPAR (i.e., PPPAR).

Photonic Beamforming Based on Programmable Phase Shifters With Amplitude and Phase Control

Abstract: A new optically controlled phased array beamforming technique based on phase modulations of wavelength-division-multiplexed (WDM) single sideband modulated light with carrier using a two-dimensional array liquid crystal on silicon (LCoS) pixels device, is presented. It realizes multiple wideband photonic microwave phase shifters, operates over a wide frequency range, and simultaneously integrates the array phase taper and the array amplitude taper within a single unit. The beamforming is software programmable. Experimental results demonstrate multiple independent microwave phase shifters that operate simultaneously over a 10- to 20-GHz frequency range, and results demonstrate beamsteering in a four-element optically controlled beam steering array at 18 GHz.

Mutual coupling suppression in microstrip array using defected ground structure

Abstract: A defected ground structure (DGS) is used to suppress mutual coupling between elements in a microstrip array and eliminate the scan blindness in an infinite phased array. Two kinds of DGSs, namely back-to-back U-shaped and dumbbell-shaped DGSs, are analysed and compared. The analysis indicates that the back-to-back U-shaped DGS is better at suppressing propagation of surface waves in microstrip substrate. A two-element microstrip array with back-to-back U-shaped DGS is designed and the array characteristics against different element distances are studied. The results show that the degree of the mutual coupling suppression is increased when the element distance is reduced. However, compared with the traditional array, a higher gain and lower side lobes are obtained when a larger element spacing is selected. The scan blindness of an infinite microstrip phased array in E-plane is studied by simulation, and the calculation demonstrates that the scan blindness can be eliminated by applying a back-to-back U-shaped DGS to the infinite phased array.

Low-Cost Phased-Array Antenna Using Compact Tunable Phase Shifters Based on Ferroelectric Ceramics

Abstract: A low-cost phased-array antenna at 10 GHz is presented for a scan angle of ±50°. The array employs continuously tunable phase shifters based on a screen printed barium-strontium-titanate thick-film ceramic. Due to the use of artificial transmission line topology, the proposed phase-shifter design has a very compact size (3 mm × 2.8 mm) for 342° total phase shift. In the frequency range from 8 to 10 GHz, it exhibits a figure of merit >;52°/dB, which is among the best of phase shifters based on ferroelectric thick films. In a prototyped phased array, the RF circuit consists of a feeding network, phase shifters, and antenna elements, which are integrated into one planar metallization layer. Furthermore, a simple way for routing bias lines for phase shifters is demonstrated using high resistive electrodes. Using screen printed thick films and applying a simplified fabrication process for the RF and bias circuitry can reduce the total expense of phased arrays considerably.

Millimeter-Wave Wafer-Scale Silicon BiCMOS Power Amplifiers Using Free-Space Power Combining

Abstract: This paper presents the first millimeter-wave wafer-scale power-amplifier array implemented in a 0.13-μ m BiCMOS technology. The power combining is done in the free-space using high efficiency on-chip antennas. A 3 × 3 power-amplifier array is demonstrated with an equivalent isotropic radiated power of 33-35 dBm at 90-98 GHz. This results in a total on-chip power of 21-23 dBm and a total radiated power of 17.5-19.5 dBm. The measured patterns of the array show single-mode operation and ~100% free-space power-combining efficiency with a 3-dB beamwidth of 28° and a directivity of 15.5 dB (gain of 12 dB). The total power-combining efficiency including the antenna losses is 45±10%. The application areas are in millimeter-wave transmitters and wafer-scale phased arrays.

Method and system for a phased array antenna embedded in an integrated circuit package

Abstract: Aspects of a method and system for configurable antenna in an integrated circuit package are provided. In this regard, a phased array antenna embedded in a multi-layer integrated circuit (IC) package may be utilized for transmitting and/or receiving signals. An IC enabled to transmit and/or receive signals may be bonded to the multi-layer IC package and may communicate a reference signal and/or one or more phase shifted versions of said reference signal to the antenna. One or more phase shifters (fabricated, for example, in planar transmission line) may be embedded in the multi-layer IC package and may be controlled via an IC bonded to the multi-layer IC package. The phased array antenna may comprise a plurality of antenna elements which may each comprise an interconnection for communicatively coupling to an associated transmitter and/or receiver, a feeder line, a quarter wavelength transformer, and a radiating portion (e.g., a folded dipole).

High-Temporal-Resolution Capabilities of the National Weather Radar Testbed Phased-Array Radar

Abstract: Since 2007 the advancement of the National Weather Radar Testbed Phased-Array Radar (NWRT PAR) hardware and software capabilities has been supporting the implementation of high-temporal-resolution (∼1 min) sampling. To achieve the increase in computational power and data archiving needs required for high-temporal-resolution sampling, the signal processor was upgraded to a scalable, Linux-based cluster with a distributed computing architecture. The development of electronic adaptive scanning, which can reduce update times by focusing data collection on significant weather, became possible through functionality added to the radar control interface and real-time controller. Signal processing techniques were implemented to address data quality issues, such as artifact removal and range-and-velocity ambiguity mitigation, absent from the NWRT PAR at its installation. The hardware and software advancements described above have made possible the development of conventional and electronic scanning capabil...

Frequency Selective Reflectarray Using Crossed-Dipole Elements With Square Loops for Wireless Communication Applications

Abstract: A new frequency selective reflectarray (FSR) comprising a crossed-dipole array and a frequency selective surface (FSS) of square loops printed on both sides of a dielectric substrate is presented for wireless communication applications. The reflectarray functions as a reflector, and generates the desired reflected beam shape while steering the primary wave source in the desired direction. Moreover, the FSR should be partially transparent for propagation channels of other communication systems working in other frequency bands. Some new FSR designs comprising 11 by 7 elements for dual-source and dual-polarized operation are given and verified by simulation and experiment. Furthermore, the FSR is applied to a WCDMA system to eliminate blind spots in communications between the base station and mobile users. A practical link budget analysis demonstrates the effectiveness of the FSR to improve the quality of communications. Finally, the proximity effect of concrete wall on the FSR is discussed to illustrate the applicability and flexibility of the proposed frequency selective reflectarray.