Showing papers on "Active antenna published in 2013"

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

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

A 108–114 GHz 4 $\,\times\,$ 4 Wafer-Scale Phased Array Transmitter With High-Efficiency On-Chip Antennas

Abstract: This paper presents a W-band wafer-scale phased- array transmitter with high-efficiency on-chip antennas. The 4 × 4 array is based on an RF beamforming architecture with an equiphase distribution network and phased shifters placed on every element. The differential on-chip antennas are implemented using a 100 μm thick quartz superstrate and with a simulated efficiency of ~ 45% at 110 GHz. The phased array is designed with low mutual coupling between the elements and results in a stable active antenna impedance versus scan angle. The phased array is built in the Jazz SBC18H3 SiGe BiCMOS process, and is 6.5 × 6.0 mm2. Measurements show two-dimensional pattern scanning capabilities with a directivity of 17.0 dB, an array gain of ~26.5 dB at 110 GHz, and an EIRP of 23-25 dBm at 108-114 GHz. The power consumption is 3.4 W from a 1.9 V supply. To our knowledge, this work represents the first W-band wafer-scale phased array to-date. The application areas are in point-to-point communication systems in the 100-120 GHz range.

A Wearable Active Antenna for Global Positioning System and Satellite Phone

Abstract: A wearable multiband circularly polarized active antenna is presented for use in Global Positioning System and Iridium satellite phone applications. The square patch antenna is constructed using flexible foam and fabric substrates and conductors etched on thin copper-on-polyimide films. The feed substrate integrates a compact low-noise amplifier chip directly underneath the antenna patch. The antenna performance is studied under bending conditions and in the presence of a human body. The active antenna exhibits a gain higher than 25 dBi and a 3 dB axial ratio bandwidth exceeding 183 MHz in free-space conditions and is robust to bending and on-body placement.

Active antenna system (AAS) radio frequency (RF) module with heat sink integrated antenna reflector

Abstract: On-board heat dissipation can be achieved in radio frequency (RF) modules by integrating a heat sink into the RF module's antenna reflector. Said integration achieves a compact and aesthetically pleasing RF module design that reduces the overall footprint of modular active antenna systems (AASs). Embodiment antenna reflectors include portions that are perforated and/or exposed to free flowing air to provide enhanced heat dissipation capability.

Integrated 60-GHz Antenna on Multilayer Organic Package With Broadside and End-Fire Radiation

Abstract: Existing antenna and array systems for 60-GHz wireless personal area network communications suffer from inherent poor radiation at grazing angles. This limitation is overcome in this work with a highly integrated antenna module that combines both broadside and end-fire radiators in a single multilayer organic package. Liquid crystal polymer and Rogers RO3003 are used to implement a small form factor (12.5 mm × 10 mm × 1.3 mm) antenna architecture. The co-designed broadside and end-fire antennas are characterized and measured for operation in the 57-66-GHz frequency range. Measured boresight gains of 8.7 and 10.9 dBi are achieved for the broadside and end-fire antennas while maintaining 35-45-dB isolation between both antennas. The numerically estimated radiation efficiency is found to be 92.5% and 78.5% for the broadside and end-fire elements. These antennas are orthogonally polarized and suitable for frequency reuse. Integrated circuits are mounted inside recessed cavities to realize a fully active antenna module with beam switching or simultaneous radiation. To the best of our knowledge, this is the first publication of a single package multilayer integration of millimeter-wave active antennas with both azimuth and elevation coverage.

Radio signal pickup from an electrically conductive substrate utilizing passive slits

Abstract: Embodiments of the present application relate generally to electronic hardware, computer software, wireless communications, network communications, wearable, hand held, and portable computing devices for facilitating communication of information and presentation of media. An electrically conductive substrate, such as a sheet of metal or metal alloy, for example, includes an active antenna formed by a slot or opening formed in the substrate, and also includes at least one separate passive slot or opening (e.g., a passive slit) formed in the substrate. The active antenna may be intentionally detuned from one or more target frequencies (e.g., 802.11, 2.4 GHz, 5 GHz) such that the active antenna is not optimized (e.g., is not tuned) for the one or more target frequencies. One portion of the active antenna may be electrically coupled with a ground potential. Another portion of the active antenna may be electrically coupled with a RF receiver, transmitter, or transceiver.

3D beamforming designs for Single User MISO systems

Abstract: In this paper, we study a transmit beamforming technique for multiple input single output downlink single-user systems with three dimensional antennas where a transmit antenna gain is determined in three dimensional coordinates. In general, the transmit antenna gain is controlled by adjusting the boresight of antennas in directional antennas. To derive the optimal tilting angles for the directional antenna systems, we provide the probability density functions (PDF) of the three dimensional user distribution. Furthermore, based on the PDF, the analysis for the average rates of passive and active antenna systems is presented. Simulation results verify the accuracy of the performance analysis.

Procedure for Measurement, Characterization, and Calibration of Active Antenna Arrays

Abstract: The GEOdesic Dome Antenna is an interesting design for efficient satellite-tracking prototypes based on 45 elements active antenna arrays manufactured by the Radiation Group of the Technical University of Madrid. Extensive measurement campaign in RF laboratories and in an anechoic chamber was performed for complete calibration and characterization of those active antenna arrays, resulting in the proposal of a new efficient procedure. To accomplish the calibration procedure, the expansion of equations of the proposed calibration algorithms, based on the proposed active antenna array model and the derivation of the scattering matrix from the active element pattern, is presented. These algorithms deal with mutual coupling effect and gain and phase errors, and in general, the overall procedure leads to a significant reduction in time and costs associated to the measurements of the antenna under test and the proposed calibration algorithm. Significant measurement results from the Certified Laboratory of Tests and Standardization of Antennas (LEHA) located in the Universidad Politecnica de Madrid are presented to validate the procedure.

Method and device for testing radio frequency index and wireless index of active antenna system

Abstract: A method and apparatus for testing a radio frequency index and a wireless index of an active antenna system are provided. A probe-type testing cover based on a near field coupling mode is adopted to test the radio frequency index of the tested active antenna system. The method comprises testing cover monomer calibration, testing cover environment calibration, radio frequency index test, putting the tested active antenna system into the testing cover, wherein the test environment is the same as the calibration environment, and performing radio frequency test on the tested active antenna system through a radio frequency port of a test probe after compensating the test environment according to a calibration result obtained from the calibration. Further a comprehensive testing method is provided.

An Active Reconfigurable Antenna at 60 GHz Based on Plate Inhomogeneous Lens and Feeders

Abstract: The conception and performances of a 60 GHz active antenna, reconfigurable in terms of radiation pattern is described in this paper. This antenna is based on a plate inhomogeneous Luneburg lens fed by several ridged waveguide sources. The manufacturing technique of the plate lens is briefly described and its measured radiation patterns are given, showing the good performances of this lens. Simulated and measured radiation patterns are given for a passive lens antenna fed by several sources. The results show the beam scanning capability of this antenna. The active antenna is described and measurements of radiation patterns for several beams are given and demonstrate the beam scanning and beam shaping reconfigurability.

Self-Oscillating Semi-Ring Active Integrated Antenna With Frequency Reconfigurability and Voltage-Controllability

Abstract: A compact frequency-agile self-oscillating semi-ring active integrated antenna is presented and investigated. Without changing the circuit footprint, the proposed active antenna achieves frequency reconfigurability and voltage-controllability simultaneously with a PIN diode, a varactor diode, and proper biasing network. The oscillation frequency can be controlled from 4.47-4.85 GHz in the OFF state and 5.03-5.33 GHz in the ON state. The VCO gains are 17.7 and 16.4 MHz/V in the two states. Benefitting from the feedback path, the proposed active antenna, with a miniature size of 0.046λ02, shows well-behaved phase noises of -106.2 and -98.7 dBc/Hz at a 1-MHz offset from the carriers.

Frequency-Reconfigurable Self-Oscillating Active Antenna With Gap-loaded Ring Radiator

Abstract: We investigate a new topology for realizing a compact frequency-reconfigurable self-oscillating active integrated antenna. The new design consists of a passive ring radiator, an unstable transistor, and two p-i-n diodes. Two gaps are etched across the radiator, with the diodes bridging the gaps to switch the antenna topology. By properly selecting the location of the gap with respect to the gate/drain terminals, the oscillation can be stabilized at two distinct frequencies, each associated with a resonance mode of the ring radiator. The simulated methods and experimental results are introduced in this letter, along with the discussion of design principles and considerations.

Space-time codes for active antenna systems: Comparative performance analysis

Abstract: In this paper, the basic tools for performance analysis of space-time coding for active antenna systems (or colocated coherent MIMO systems) are presented, and illustrated with four different space-time codes: M-sequences, Alltop codes - quadratic and cubic -, and multiple shifted chirps. The relative effectiveness of these different codes is then measured with specific factors of merit, designed for radar performances evaluation. These factors of merit, easily extracted from the ambiguity functions, are shown to allow operational consequences to be drawn from space-time codes characteristics. (6 pages)

Test method and device for wireless indexes of active antenna system

Abstract: The invention discloses a test method and a device for wireless indexes of an active antenna system. An over the air (OTA) test is used for testing spatial characters of the active antenna system and a near field coupling mode is used for testing radio frequency indexes of the active antenna system. The invention also provides a near field coupling test device which is a radio frequency testing cover. By the aid of the near field coupling test device, the radio frequency index test can be conducted to the active antenna system which is an integral device of an antenna and a multi-channel transceiver under the condition that any extra test interfaces are not required to be added. According to the comprehensive test method, the advantages of the OTA test and the near field coupling mode are combined fully, the defects and the problems of the OTA test and the near field coupling mode are overcome, and the test efficiency and the test cost are optimized.

Apparatus and method for an active antenna system with near-field radio frequency probes

Abstract: Field-serviceable radio frequency modules can be achieved by replacing hard-wired radio frequency (RF) feedback paths with external near-field RF probes. Notably, the near-field RF probes may allow for the RF module to be installed/re-installed on a backplane or other support structure without fowling factory calibration settings. Multiple near-field RF probes can monitor a single RF module. Additionally, a single near-field RF probe can monitor multiple RF modules.

Series-connected couplers for active antenna systems

Abstract: In one embodiment, an antenna system has a plurality of antenna paths and a calibration circuit. Each of the antenna paths has a transceiver and an antenna element. The calibration circuit has (i) a calibration transceiver and a different coupler coupled to each antenna path. The couplers are connected in series with one another and with the calibration transceiver. Connecting the couplers in series, rather than in parallel, reduces the amount of cabling needed and the need for a combiner/splitter or switch matrix between the couplers and the calibration transceiver, thereby reducing the cost, volume, and/or weight associated with the calibration circuit.

Solar powered Class-E active antenna oscillator for wireless power transmission

Abstract: The design of a compact and efficient autonomous signal generator for wireless power transmission applications is presented. The design is based on the use of a Class-E active antenna oscillator operating at 905 MHz that obtains the DC power needed to operate from solar energy. The selected topology integrates flexible solar cells sharing the surface of the antenna element leading to a compact design. Parallel connection of solar cells is used in order to maximize the available current, and optimize performance for low light spectral irradiance. Harmonic balance optimization is used to maximize the DC-to-RF conversion efficiency of the oscillator. A prototype is fabricated and the simulated results are compared with measurements.

Antenna structure with reconfigurable patterns

Abstract: An antenna structure with reconfigurable patterns includes a grounded plane, at least one active antenna, and at least one current dragger. The active antenna is disposed adjacent to a side of the grounded plane, while the current dragger is disposed adjacent to another side of the grounded plane. The current dragger includes at least one switch. The at least one switch is configured to selectively conduct a current at the grounded plane to the current dragger or electrically insulate a current at the grounded plane from the current dragger.

Design of a networked robotic system capable of enhancing wireless communication capabilities

Abstract: In this paper, we present the design of a networked robotic system capable of enhancing wireless communication capabilities. The core of the system is active antenna tracking with directional antennas. The proposed system is decentralized and consists mainly of a mobile robot system and a command center system. Each system is equipped with off-the-shelf network devices such as antennas, access points (AP), and network switches. For directional antennas to be beneficial to our system, we propose a weighted centroid algorithm (WCA), which is a method for active antenna tracking and direction of arrival (DOA) estimation. Through extensive field experiments in different environments and with different antenna selections, such as omni-to-omni, omni-to-directional, directional-to-directional antennas, we demonstrate the feasibility of our proposed system. We expect that our system can be applied in a variety of rescue, surveillance, and emergency scenarios where high bandwidth and long distance communications are needed.

Multi leveled active antenna configuration for multiband MIMO LTE system

Abstract: An active antenna system and algorithm is described that provides for dynamic tuning and optimization of antenna system parameters for a MIMO system where correlation and isolation between antennas in the system are dynamically altered to provide for greater throughput. As one or multiple antennas are loaded or de-tuned due to environmental changes, corrections to correlation and/or isolation are made by selecting the optimal antenna radiation pattern and by adjusting electrical length and/or reactive loading of transmission lines connecting the antennas. Multiple Isolated Magnetic Dipole (IMD) antennas are co-located and connected with a feed network that can include switches that adjust phase length for transmission lines connecting the antennas. Filtering is integrated into the feed network to improve rejection of unwanted frequencies. Filtering can also be implemented on the antenna structure.

Active antenna system with distributed transceiver system

Abstract: The object of the present invention is to provide an active antenna system which is flexibly configurable and efficient in operation. According to a first aspect of the present invention an active antenna system comprises a radio equipment having a plurality of transceiver modules, each transceiver module being connected to at least one antenna, and a radio equipment control unit having a hub being connected to the transceiver modules via an antenna interconnect. The hub is embodied for receiving base band signals via the antenna interconnect from the transceiver modules and to extract channel signals from the received base band signals. As the hub is arranged in the radio equipment control unit which is part of a base station the base band signals are transmitted to the radio equipment control unit without extracting the channel signals. This allows easily to distribute the base band signals on several data connections, particularly several antenna cables, of one antenna interconnect. This results in a reduced information loss and minimizes the requirements for the transmission capacity of a single data connection of the antenna interconnect between the radio equipment control unit and the radio equipment. The radio equipment control unit does receive all the information which is originally received by the transceiver modules.

Implementation of full-dimensional MIMO (FD-MIMO) in LTE

Abstract: Data-centric mobile devices poses challenges to operators on sustaining the rapid growth of mobile traffic. Recently, full-dimensional MIMO (FD-ΜΓΜΟ) emerges as a promising technique to significantly increase spectrum efficiency and has been proposed and investigated in 3GPP LTE (Long Term Evolution) and LTE-advanced (LTE-A). In FD-MIMO systems, an evolved Node B (eNB) deploys a large number of active antenna elements in a 2-dimensional (2D) grid and is capable to support many users on the same bandwidth simultaneously. In this paper, we propose a FD-MIMO framework within LTE/LTE-A standards and discuss key challenges including downlink preceding, antenna virtualization and channel quality indicator (CQI) prediction. Furthermore, we explore feasibility of implementing FD-MIMO in frequency division duplex (FDD) systems. Based on system-level simulations, FD-MIMO is shown to attain 2–5 times cell average throughput gain as well as cell-edge throughput gain, compared with 4G LTE system.

Arrangement of millimeter-wave antennas in electronic devices having a radiation energy blocking casing

Abstract: A millimeter-wave active antenna array mounting apparatus is provided. The apparatus comprises a casing having at least one slit, wherein the casing is made of a radiation energy blocking material; and a millimeter-wave active antenna array configured to radiate millimeter-wave signals, wherein radiating elements of the millimeter-wave active antenna array are disposed corresponding to an opening of the at least one slit, thereby enabling an efficient radiation of the millimeter-wave signals through the casing.

Apparatus and Method for Modular Multi-Sector Active Antenna System

Abstract: Multiple radio frequency (RF) modules can be arranged in a multi-sector configuration. Each RF modules may have a wedge-like shape such that the RF modules may be adjacently affixed to one another in spherical cluster, thereby providing multi-sector coverage while maintaining a relatively compact active antenna installation. Additionally, multiple clusters of RF modules can be arranged in an array to provide beamforming and/or other advances antenna functionality.

On the potential of traffic driven tilt optimization in LTE-A networks

Abstract: Performance and efficiency of a cellular network can be enhanced by properly adjusting the antenna tilt setting. Antenna tilt is one of the most important radio parameters that determines the service coverage boundary and level of inter-cell-interference in cellular systems. Moreover, tilt tuning is an effective technique in radio network optimization to effect a better load balance among cells for efficient utilization of spare radio resources. The variability of user traffic distribution makes it more challenging to operators to ensure the required service capacity and quality with acceptable capital and operational expenditures. Active Antenna System (AAS) features promise the ability to flexibly handle system capacity by adapting the orientation of the antenna beam. In this paper, the potential performance gains of tilt optimization for differently placed user traffic concentrations are investigated. Simulation results show that users at traffic hot spot areas suffering from resource sharing can achieve significant performance gains from traffic oriented tilt optimization.

Performance Evaluation of 3D MIMO LTE-Advanced System

Abstract: This paper demonstrates a simulation methodology based on a reasonable 3D channel model System level simulations on various 3D antenna port configurations are performed, and results are compared with those of 2D MIMO system Several interesting observations are made from the evaluation results: (1) the vertically distributed active antenna elements provide less MIMO gain than the horizontally distributed active antenna elements; (2) with the same number of antenna elements, the 3D active antenna configuration can provide better performance than the 2D one, and the performance improvement is much larger for MU-MIMO than SU-MIMO; (3) even when the 2D antenna configuration has more antenna elements (providing more antenna array gain) than the 3D active antenna configuration, the 3D configuration can still outperform the 2D one if there are enough transmitter ports

Method and device for submitting signal quality measurement information

Abstract: The present invention discloses a method and a device for reporting signal quality measurement information. Main content includes: receiving, by a terminal, a signal quality measurement configuration message sent by a base station; determining signal quality measurement information according to a channel weighting instruction carried in the received signal quality measurement configuration message; and sending the signal quality measurement information to the base station, so that the base station adjusts a downtilt angle of an antenna of the base station according to the received signal quality measurement information, so as to change signal coverage of the antenna, thereby avoiding problems of system resource wastes and poor quality of service of a signal that are caused by the fact that signal coverage areas overlap when a downtilt angle of an antenna is adjusted randomly in an active antenna system, and improving the efficiency of terminal switching between cells.

Inkjet-printed RF energy harvesting and wireless power trasmission devices on paper substrate

Abstract: This paper presents an overview of the state-of-the-art inkjet-printed energy harvesting and wireless power transfer technology on paper substrate. RF energy harvesting devices utilizing a charge pump circuit or an active antenna based wireless power transmission device are presented. Inkjet printing technology on paper substrate and fabrication techniques, along with a variety of applications, are presented with particular focus on low-cost and eco-friendly wireless systems for wireless sensor networks.

Module for an active antenna system

Abstract: A module for an active antenna system for receiving and transmitting radio signals sealed in a housing. It comprises a power connector placed at the outside of the housing for supplying the module with supply power; at least one micro radio for receiving/sending digital radio signals having a digital down-converter/a digital up-converter and a control signal converter. The micro radio converts the digital radio signals to analog RF (radio frequency) signals and vice versa and is connected to the internal bus. At least one antenna element is connected to the micro radio and an internal data bus for the exchange of digital radio data and control data is connected to micro radio and hub. By placing two or more modules next to each other on a frame these modules form an active antenna system.