Active Phased Array Antenna Research Articles

VHF antenna pattern characterization by the observation of meteor head echoes

Abstract. The Middle Atmosphere Alomar Radar System (MAARSY) with its active phased array antenna is designed and used for studies of phenomena in the mesosphere and lower atmosphere. The flexible beam forming and steering combined with a large aperture array allows for observations with a high temporal and angular resolution. For both the analysis of the radar data and the configuration of experiments, the actual radiation pattern needs to be known. For that purpose, various simulations as well as passive and active experiments have been conducted. Here, results of meteor head echo observations are presented, which allow us to derive detailed information of the actual radiation pattern for different beam-pointing positions and the current health status of the entire radar. For MAARSY, the described method offers robust beam pointing and width estimations for a minimum of a few days of observations.

Pattern synthesis algorithm with limited amplitude control range for active phased array antenna

Pattern synthesis algorithm with limited amplitude control range for active phased array antenna

A Compact RF Frontend Module of Active Phased Array Antenna for High SHF Wideband Massive MIMO in 5G

A Compact RF Frontend Module of Active Phased Array Antenna for High SHF Wideband Massive MIMO in 5G

A method for measuring dynamic radiation patterns of passive and active phased antenna arrays

The study deals with a method for measuring dynamic radiation patterns of phased antenna arrays and active phased antenna arrays. The method consists of measuring the signal during electronically scanning the beam of a static antenna. We show the main differences between dynamic and static radiation patterns. The Whittaker Nyquist – Kotelnikov – Shannon sampling theorem forms the basis of our recommendations for selecting the number of measurement points in the case of a dynamic radiation pattern. We supply a diagram of a work station dedicated to measuring dynamic radiation patterns using the workbench developed by the Joint-stock company “V. Tikhomirov Scientific Research Institute of Instrument Design”. We present measured static and dynamic radiation patterns of a real-world active phased antenna array.Our method for measuring dynamic radiation patterns significantly decreases the time required for determining radiation characteristics of phased antenna arrays and active phased antenna arrays for separate angular cross-sections and over the whole visibility scope, and increases their information content. Moreover, measuring dynamic radiation patterns does not require a rotating workbench. It is possible to use dynamic radiation pattern to determine static (as measured by turning the antenna) far-field patterns, to restore electric current magnitude and phase distribution over the aperture and to troubleshoot the antenna.

재귀적 소자 교환 방식을 이용한 능동위상배열안테나 부배열 구조 최적화 알고리즘

재귀적 소자 교환 방식을 이용한 능동위상배열안테나 부배열 구조 최적화 알고리즘

A proposal on the study of solar‐terrestrial coupling processes with atmospheric radars and ground‐based observation network

AbstractThe solar energy can mainly be divided into two categories: the solar radiation and the solar wind. The former maximizes at the equator, generating various disturbances over a wide height range and causing vertical coupling processes of the atmosphere between the troposphere and middle and upper atmospheres by upward propagating atmospheric waves. The energy and material flows that occur in all height regions of the equatorial atmosphere are named as “Equatorial Fountain.” These processes from the bottom also cause various space weather effects, such as satellite communication and Global Navigation Satellite System positioning. While, the electromagnetic energy and high‐energy plasma particles in the solar wind converge into the polar region through geomagnetic fields. These energy/particle inflow results in auroral Joule heating and ion drag of the atmosphere particularly during geomagnetic storms and substorms. The ion outflow from the polar ionosphere controls ambient plasma constituents in the magnetosphere and may cause long‐term variation of the atmosphere. We propose to clarify these overall coupling processes in the solar‐terrestrial system from the bottom and from above through high‐resolution observations at key latitudes in the equator and in the polar region. We will establish a large radar with active phased array antenna, called the Equatorial Middle and Upper atmosphere radar, in west Sumatra, Indonesia. We will participate in construction of the EISCAT_3D radar in northern Scandinavia. These radars will enhance the existing international radar network. We will also develop a global observation network of compact radio and optical remote sensing equipment from the equator to polar region.

On the performance of array antennas with mechanical distortion errors considering element numbers

ABSTRACTMechanical distortion errors in active phased-array antennas (APAA) include both random error and mechanical distortion. Random error is generated during the manufacturing and assembly process, and mechanical distortion is caused by external loads such as high thermal difference, vibration and impact loads. The combination of random error and mechanical distortion results in unexpected and significant degradation of the antenna electromagnetic performance, which has become an obstacle to development of high-performance APAA. After introducing the mechanical distortion errors into the antenna electric field as an additional phase factor, a coupled structural-electromagnetic model of the planar rectangular APAA was developed to describe the coupling relationship between mechanical distortion error and electromagnetic performance. The combined influences of the radiated element numbers, mechanical distortion and element position random error on the antenna electromagnetic performances are analysed, and valuable results for engineering application are discussed.

Beam control algorithm for an active phased array antenna with dome lens

An algorithm for control of the phases of an active phased array antenna (APAA) with dome lens that takes into account distorting influence of the lens and combines tabular and computational methods for control of the antenna element phases is proposed. An algorithm for control of the amplitude transmission coefficients of receiving channels of the APAA modules for formation of a difference pattern with deep direction- finding null is also proposed.

완전 디지털 레이다에 적용 가능한 능동위상배열안테나 근접전계 수신 시험

완전 디지털 레이다에 적용 가능한 능동위상배열안테나 근접전계 수신 시험

MST Radars of Chinese Meridian Project: System Description and Atmospheric Wind Measurement

Based on the construction of the Chinese Meridian Project, two mesosphere, stratosphere, and troposphere (MST) radars were designed and located in Beijing and Chongyang, Hubei province, China, to investigate the atmospheric dynamics in the troposphere, stratosphere, and mesosphere. The official names of the two radio systems are Beijing MST radar and Wuhan MST radar. They are the monostatic radars with an active phased antenna array consisting of 576 Yagi antennas and operated by a 53.8-MHz frequency. The three-element Yagi antennas are arranged in a square grid of 96-m side length to form the aperture of 9216 m2. This antenna array arrangement forms the five symmetric radar beams of vertex, east, west, south, and north. The beamwidth is 3.2°, the maximum directive gain is 34.8 dB, and the total transmitting peak power is ∼172 kW. The zenith angle of the oblique beams is adjustable between 0 and 20° with a 1° step. The average power aperture product of the radars is $3.2\times 10^{8} \text{Wm}^{2}$ . There are three operating modes of the MST radars, including the low, middle, and high modes, applied to observe the troposphere, stratosphere, and mesosphere, respectively. Thus, these two coherent pulse Doppler MST radars have the ability to study the features of the midlatitude atmospheric turbulence and wind field vector from the troposphere to the lower thermosphere with high spatiotemporal resolution. In this paper, the antenna array, system hardware, and signal processing methods, as well as the typical observation results of the troposphere, stratosphere, and mesosphere, are introduced.

Improved Phase-Encoding Calibration for Active Phased-Array Antennas of SAR

Calibration of the active phased-array antennas for synthetic aperture radar (SAR) is a complicated mission. The phase-encoding method is used to monitor and characterize individual transmit/receive modules of the active phased-array antenna, which has been demonstrated to be an effective method by TerraSAR-X in a spaceborne environment. The error source due to finite phase-encoding setting accuracy is modeled and analyzed, based on which a modification of the phase-encoding matrix is done to improve the measurement accuracy. Furthermore, simulation confirms a significant improvement in the measurement accuracy with the modification, showing an agreement with the model-based theoretical analysis.

Design of a compact multilayer circularly polarized phased array transmit antenna system for satellite applications

An active phased array antenna which can scan its beam direction to a wide range of scan angles is presented in this paper. The paper proposes a new technique to compact a phased array antenna and making it suitable for applying in satellite payloads. This antenna should transmit high data rate signal from satellite to ground stations; and by spatial power combining the needed Effective Isotropic Radiated Power (EIRP) for the transmission link will be provided. The main beam can be scanned to 50° from normal. Polarization of the radiated wave of this antenna is circular. The designed antenna benefits from microstrip technology and has a unique low mass multilayer structure with two different substrates. For implementing antenna’s RF circuits, Microwave Monolithic Integrated Circuits (MMICs) have been used and they are integrated expertly with microstrip radiators. Beam controller board sends necessary commands to MMICs for setting phase and amplitude of each array module. For decreasing side lobe level in high scan angles, genetic algorithm is applied and excitations of array elements are optimized. Design stages and simulation results of the array antenna are summarized in this paper and the results are compared with test results.

Graphene-based fine-tunable optical delay line for optical beamforming in phased-array antennas.

The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τg=920 ps) together with a compact footprint (4.15 mm2) and optical loss <27 dB make this device particularly suitable for highly efficient steering in active phased-array antennas. The delay line includes two graphene-based Mach-Zehnder interferometer switches and two vertically stacked microring resonators between which a graphene capacitor is placed. The tuning range is obtained by varying the value of the voltage applied to the graphene electrodes, which controls the optical path of the light propagation and therefore the delay time. The graphene provides a faster reconfigurable time and low values of energy dissipation. Such significant advantages, together with a negligible beam-squint effect, allow us to overcome the limitations of conventional RF beamformers. A highly efficient fine-tunable optical delay line for the beamsteering of 20radiating elements up to ±20° in the azimuth direction of a tile in a phased-array antenna of an X-band synthetic aperture radar has been designed.

Coupled structural-electromagnetic modeling and analysis of hexagonal active phased array antennas with random errors

The structural and electromagnetic performances of planar hexagonal active phased array antenna (APAA) are degraded because of the position errors of radiating elements caused by manufacturing processing, assembly and environment loads. It seriously restricts the realization of high performances of phased array antenna. By considering the changeable mutual coupling parameters and introducing the structural distortion factor into the antenna pattern function, the coupled structural-electromagnetic model of planar hexagonal array antennas was developed. The quantitative relationship between the structural error and the electromagnetic performances of antenna was discussed with consideration of the mutual coupling. The influence of the plane assembling accuracy and flatness on antenna performance was analyzed with the change in the number of array elements. The presented valuable simulation results could be used in antenna engineering to provide guidance for the antenna designers to set the optimal performance-driven tolerance in manufacturing antenna.

Multiobjective Optimization Method for Multichannel Microwave Components of Active Phased Array Antenna

Multichannel microwave components are widely used and the active phased array antenna is a typical representative. The high power generated from T/R modules in active phased array antenna (APAA) leads to the degradation of its electrical performances, which seriously restricts the development of high-performance APAA. Therefore, to meet the demand of thermal design for APAA, a multiobjective optimization design model of cold plate is proposed. Furthermore, in order to achieve temperature uniformity and case temperature restrictions of APAA simultaneously, optimization model of channel structure is developed. Besides, an airborne active phased array antenna was tested as an example to verify the validity of the optimization model. The valuable results provide important reference for engineers to enhance thermal design technology of antennas.

In-Orbit Antenna Pattern Extraction Method for Active Phased-Array SAR Antennas

In this letter, we propose a novel in-orbit antenna pattern extraction method for active phased-array SAR antennas using T/R module calibration data. The antenna pattern extraction methodology based on T/R calibration data is demonstrated. Unlike previous methods that only verify the mainlobe antenna pattern based on a distributed target, the proposed method can be utilized to verify the mainlobe pattern as well as the sidelobe antenna pattern, regardless of the accessibility to a distributed ground target. The in-orbit KOMPSAT-5 SAR antenna pattern verification result is presented using data extracted from the dedicated T/R calibration technique.

Validation of the radiation pattern of the VHF MST radar MAARSY by scattering off a sounding rocket's payload

Abstract. The Middle Atmosphere Alomar Radar System (MAARSY) is a monostatic radar with an active phased array antenna designed for studies of phenomena in the mesosphere and lower thermosphere. Its design, in particular the flexible beam forming and steering capability, makes it a powerful instrument to perform observations with high angular and temporal resolution. For the configuration and analysis of experiments carried out with the radar it is essential to have knowledge of the actual radiation pattern. Therefore, during the time since the radar was put into operation various active and passive experiments have been performed to gain knowledge of the radiation pattern. With these experiments the beam pointing accuracy, the beam width and phase distribution of the antenna array were investigated. Here, the use of a sounding rocket and its payload as a radar target is described which was launched in the proximity of the radar. The analysis of these observations allows the detailed investigation of the two-way radiation pattern for different antenna array sizes and beam pointing positions.

Quality analysis of automatic control active phase chart orientation antenna arrays

The paper presents an analysis of automatic control diagram direction active phased antenna arrays. The expediency of building modules active phased antenna arrays based on minimizing the mean square error conditions control system diagram direction. The author stresses the relevance of applying the proposed method to estimate the extent of quality control system diagram direction.

기판집적 도파관(SIW)을 기반으로 하는 고효율 능동 위상 배열안테나

저손실, 전자기 완전차폐, 고전력 특성을 갖는 기판집적 도파관(SIW)을 이용하여 X-band <TEX>$8{\times}16$</TEX> 이중편파 능동 위상배열안테나 시스템을 구현하였다. 16-way SIW 전력분배 네트워크의 측정된 순수 삽입손실(0.65 dB)은 마이크로스트립 경우보다 1 dB 감소하였으며, SIW 부배열(<TEX>$1{\times}16$</TEX>) 안테나 소자의 측정된 방사효율(73 %)은 약 2배(3 dB) 향상되었다. 이러한 SIW를 이용한 분배손실과 방사효율의 상당한 개선은 능동 위상 배열안테나 시스템에서 고전력 증폭기의 최대출력(P1 dB)을 저감하고, 총 전력소모를 약 30 % 절감할 것이다. SIW 기반으로 제작된 X-band <TEX>$8{\times}16$</TEX> 이중편파 능동 위상 배열안테나 시스템을 이론적인 제어벡터만을 생성하여 0도, 5도, 9도, 18도의 정밀한(최대편차 2도) 빔 조향을 측정하였으며, 열주기/진공 시험에서 우주환경 적합성을 확인하였다. 고효율 SIW 배열안테나 시스템은 고성능 레이더는 물론 차세대 무선통신(5G)을 위한 Massive MIMO와 다양한 밀리미터파 통신시스템(60 GHz WPAN, 77 GHz 자동차 레이더, 초고속 디지털 전송시스템 등)에 매우 유용할 것으로 기대한다. An X-band <TEX>$8{\times}16$</TEX> dual-polarized active phased array antenna system has been implemented based on the substrate integrated waveguide(SIW) technology having low propagation loss, complete EM shielding, and high power handling characteristics. Compared with the microstrip case, 1 dB less is the measured insertion loss(0.65 dB) of the 16-way SIW power distribution network and doubled(3 dB improved) is the measured radiation efficiency(73 %) of the SIW sub-array(<TEX>$1{\times}16$</TEX>) antenna element. These significant improvements of the power division loss and the radiation efficiency using the SIW, save more than 30 % of the total power consumption, in the active phased array antenna systems, through substantial reduction of the maximum output power(P1 dB) of the high power amplifiers. Using the X-band <TEX>$8{\times}16$</TEX> dual-polarized active phased array antenna system fabricated by the SIW technology, the main radiation beam has been steered by 0, 5, 9, and 18 degrees in the accuracy of 2 degree maximum deviation by simply generating the theoretical control vectors. Performing thermal cycle and vacuum tests, we have found that the SIW array antenna system be eligible for the space environment qualification. We expect that the high efficiency SIW array antenna system be very effective for high performance radar systems, massive MIMO for 5G mobile systems, and various millimeter-wave systems(60 GHz WPAN, 77 GHz automotive radars, high speed digital transmission systems).

Geometric interpretation of synthesis of a quasi-optical distribution system for multibeam phased array antennas

A geometric interpretation is proposed for synthesis of a quasi-optical system employed in multi-beam active phased array antennas (APAAs). Relationships are obtained for the angles of deflections of APAA beams and for optimum positions of the probes of the distribution system. The optimization is performed according to two criteria: the minimum mean deflection and the minimum local deflection. The example of construction of a quasi-optical distribution system for a five-beam APAA is presented. Dependences of phase errors on the positions of radiators and patterns of an APAA with a sidelobe level not exceeding 40 dB are obtained.