Controlled Reception Pattern Antenna Research Articles

Analysis of the approaches to protection against interference of UAV satellite navigation receivers.

The main approaches to the construction of signal receivers of global satellite navigation systems of unmanned aerial vehicles, protected from the influence of artificially created interference, are considered. Such systems are equipped with multi-element phased antenna arrays and devices of controlled reception pattern antenna. In the process of processing the received information signal by the Controlled Reception Pattern Antenna device. the selection of interference and their suppression (compensation) is ensured, which is equivalent to the formation of dips in the spatial pattern of the antenna array at the corners that correspond to the directions of the interference sources. The basic principles of the implementation of the adaptive algorithm for processing the received information signal are given. The design and composition of the navigation receiver of the «Orlan-10» unmanned aerial vehicle equipped with a Controlled Reception Pattern Antenna device is considered. A conclusion was made regarding the fundamental possibility of creating a domestic navigation receiver with a Controlled Reception Pattern Antenna device. In the future, it is envisaged to deploy works on the creation of Controlled Reception Pattern Antenna devices with a greater number of antenna elements and the use of optimization principles of the quantitative composition of adaptation operations, in order to ensure the performance of these devices with a greater number of simultaneously enabled sources of interference and higher levels of their signal power.

RESULTS OF THE EXPERIMENT USING NAVIGATIONAL ANTENNAS WITH CONTROLLED RECEPTION PATTERN ANTENNA FOR UAVS IN AREAS OF ACTIVE SUPPRESSION BY ELECTRONIC WARFARE MEANS

The article describes the trends in development, tactics, composition, and construction of Russia's electronic warfare means, as well as the primary objectives of interference. It describes methods effectively employed on the battlefield to reduce the impact of enemy EW assets on the navigation data quality of UAVs (Unmanned Aerial Vehicles). The general concept of using CRPA (Controlled Reception Pattern Antenna) for military users' navigation is outlined.
 Experiments were conducted to assess the influence of EW means on one of the most popular CRPAs with four antenna elements in real conditions of active combat. Flights were carried out simultaneously by two UAVs, the first equipped with CRPA and the second integrated with a standard GNSS receiver. The flights were conducted under identical conditions, simultaneously conducting reconnaissance of the same targets. Data on the average height loss of navigation signal reception for UAVs were obtained.
 According to the experiment results, the integration of CRPA with four antenna elements can be effective for strike UAVs with weapon release systems that require precise positioning for target engagement, provided that the flight altitude of such UAVs does not exceed 150-250 meters in areas with minimal enemy EW interference. Otherwise, it is recommended to use CRPA with 8 or more elements or explore other promising technologies.
 Recommendations for integrating the aforementioned antennas are developed, and the accompanying issues associated with their application are discussed. The article also outlines options for expanding CRPA integration capabilities and ways to upgrade their software and hardware components.

A Modified Anti-Jamming Method Using Dual-Polarized Ellipsoid Minimum Variance Distortionless Response to Predict the Coverage Ratio of Global Positioning System Signal

The dual-polarized array is considered as one of the key anti-jamming techniques due to twice counts of the jamming signals suppressed relative to a monopolar array. This paper proposes an adaptive anti-jamming dual-polarized ellipsoid minimum variance distortionless response (EMVDR) method to evaluate the carrier-to-noise ratio (<inline-formula> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> a/<inline-formula> <tex-math notation="LaTeX">${N}_{{0}}$ </tex-math></inline-formula>) for global positioning system (GPS) coverage. Firstly in GPS L1 band, the dual-polarized gains obtained by controlled reception pattern antenna (CRPA) array are investigated as the signal model of GPS coverage evaluation. Secondly, a novel EMVDR method based the Hermitian tridiagonal loading technique is proposed to obtain the smooth anti-jamming weight matrix, which is against the system error by using the highpass filtering performance of Hermitian tridiagonal matrix. Finally, <inline-formula> <tex-math notation="LaTeX">${C}\text{a}/{N}_{{0}}$ </tex-math></inline-formula> based the proposed EMVDR is used to evaluate the coverage percentage of the GPS signal, namely <inline-formula> <tex-math notation="LaTeX">${C}\text{a}/{N}_{{0}}$ </tex-math></inline-formula> needs to be beyond a threshold of <inline-formula> <tex-math notation="LaTeX">$28~\text {dB}\cdot \text {Hz}$ </tex-math></inline-formula> by recovering GPS signal. Through many Monte Carlo simulations, the results indicate that the anti-jamming performance of proposed EMVDR method outperforms the classic minimum variance distortionless response (MVDR) based the space adaptive processing (SAP) and the space time adaptive processing (STAP), and the GPS coverage ratio can keep from 60&#x0025; to 70&#x0025; until degrees of freedom (DOFs) are exhausted to zero.

Design and analysis of controlled reception pattern antenna arrays

ABSTRACTThis paper describes the design and analysis of controlled reception pattern antenna (CRPA) arrays. The algorithm of the CRPA system minimizes the array output power with a constraint that the power of the look direction maintains a constant or unity. The proposed approaches use different permittivities and sizes between one reference and auxiliary elements of the CRPA arrays. Due to the low permittivity and large size of one reference element, the CRPA arrays not only have much better sensitivity of a user’s GPS receiver but also maintain the performance of the null depth of the CRPA system.

Compact zeroth-order resonator (ZOR) antennas

In this paper, we introduce and review the zeroth-order resonator (ZOR) antennas with outstanding characteristics including various applications that have been researched so far. Since the zeroth-order resonance frequency is independent of a physical length of antenna, the ZOR antenna can theoretically be designed quite small and have a possibility to apply to considerably lots of applications. First, we have presented the ZOR antennas implemented by double-negative (DNG), epsilon-negative (ENG), and mu-negative (MNG) transmission lines. Then, the research related on extremely small, wide beamwidth, wideband, and circularly polarized (CP) ZOR antennas have been continuously carried out. Based on a series of these studies, the ZOR antennas were utilized for various applications such as a wireless power transfer (WPT), a compact controlled reception pattern antenna (CRPA), a penta-band mobile antenna, and a wide steering array antenna.

Efficiency of the Miniature Anti-jam GNSS Antenna Array

The use of the miniature controlled reception pattern antennas (CRPAs) in GNSS equipment is one of the trends in GPS, Baidow, GLONASS development. A miniaturized GPS antenna array technology reduces the size of the antenna elements and the array dimensions. Miniature CRPAs are in demand not only with mass consumer of GPS/GLONASS house-hold equipment, but with expert users of complex hardware as well, where high-tech multi-sensor miniature antenna systems (AC) can be applied. Such types of AC used for intelligent control of spatial selectivity are considered as antenna arrays. The advantages of miniature CRPAs with anti-jamming capability include possibility to be installed on vehicles where it used to be impossible due to their size. The negative effect of miniaturization is in degradation of some antennas characteristics, such as gain, suppression of the reverse lobe of radiation pattern (RP), a heterogeneity of RP. In miniature antennas, the resonator interinfluence increases, that leads to distortion of individual emitters RP and to the in-crease of the total RP lobe of the antenna array irregularity, as well as the width of RP lobe. Designers take special measures to reduce the interinfluence of the resonators. However, they are not fully described in the available literature. Therefore, the achieved performance of miniature CRPAs is in great interest. The final criterion (from a consumer point of view) is in effective functional of a device containing a miniature CRPA, the degradation of its parameters in compare with traditional CRPA equipment of expert users. The authors focus on property investigation of miniature CRPAs manufactured primarily by US industry. Specifications of two antennas and some expected details of the miniaturized antenna array technology are described along with the test results of their ability to perform the objective function jammer suppression. The article contains the results obtained from independent testing of electrodynamics parameters of miniature L1/L2 frequency CRPA and its design analysis. The experimental data of sensor interinfluence are outlined. The measures to reduce the sensor interinfluence are take into account. The efficiency of the miniature antenna is estimated in the process of interference suppression by means of computer simulation. The Monte-Carlo method is applied. For the sake of generality, two types of algorithm for interference suppression are used.

Compact Controlled Reception Pattern Antenna (CRPA) Array Based on Mu-Zero Resonance (MZR) Antenna

Compact Controlled Reception Pattern Antenna (CRPA) Array Based on Mu-Zero Resonance (MZR) Antenna

An arbitrary load selector with reconfigurable impedance matching for multiple antenna selection

AbstractIn this letter, an N‐way reconfigurable load selector for multiple antenna selection is presented based on switchable impedance matching network. The proposed structure is mainly configured by a 1:7 reconfigurable power divider as an arbitrary load selector and a switchable impedance matching circuitry. The arbitrary load selector has 1 input port and reconfigurable 7 output ports that any combination of output ports like single output or multiple outputs can be selected. Since the input impedance of load selector is varied according to the number of selected output ports, the reconfigurable impedance matching circuitry consisting of a reflection‐type phase shifter and a varactor diode compensates the impedance variation in different operation modes. The proposed structure was tested at 1.575 GHz for anti‐jamming controlled reception pattern antenna (CRPA) feed network where the reconfigurable impedance matching circuitry and switching elements were controlled by micro control unit. The experimental results showed that various path modes were selectable with return loss better than 25 dB and insertion loss &lt;1.0 dB. Also, the magnitude variation in different mode was &lt;0.6 dB.

A CRPA array with dual‐mode patch antenna elements for GPS applications

AbstractA controlled reception pattern antenna (CRPA) array consisting of three dual‐mode microstrip patch antennas is designed and investigated for GPS interference mitigation applications. Each dual‐mode element consists of a dominant‐mode disk patch antenna encircled by a dual‐polarized shorted ring patch antenna. The measured input and radiation parameters of a prototype array are presented. The null‐steering performance of the array is demonstrated using a simple adaptive algorithm and is shown to be superior to the conventional planar arrays.

Evaluation of array antenna systems for global navigation satellite system applications using wave‐field synthesis in an over‐the‐air laboratory

Antenna characterisation is usually performed by antenna pattern measurements in an anechoic chamber. Subsequently, a conducted test, the radiated two-stage or the wireless-cable method can be used for an overall system evaluation considering the measured patterns. In this study, the authors present a method to perform device tests for antenna arrays/smart antennas with and without the need of radiation pattern measurements, and they validate it experimentally. By using over-the-air tests in a virtual electromagnetic environment and wave-field synthesis, the propagation environment can be realistically recreated in the region around a device-under-test. This allows for reproducible performance comparisons of different antennas or systems under identical propagation environment conditions. As a special application, they consider the controlled reception pattern antenna in a global navigation satellite systems environment in the presence of interferer signals.

Design of a Small Controlled Reception Pattern Antenna Array With a Single-Layer Coupled Feed Structure for Enhanced Bore-Sight Gain and a Matching Bandwidth

ABSTRACTThis article proposes the design of a controlled reception pattern antenna (CRPA) array with a single-layer coupled feed structure to improve the radiation gain and a matching bandwidth. Each array element consists of a feeding patch and an outer radiating loop printed on a thick ceramic substrate with a high dielectric constant. The loop is capacitively coupled to the patch and the coupling strength is adjusted by varying the gap distance. Antenna characteristics are measured in a full anechoic chamber, and an equivalent circuit is built to verify the operating principle. The results demonstrate that the proposed structure is more suitable to enhance the gain and bandwidth compared to a conventional patch antenna in small CRPA arrays.

Design of Miniaturized Microstrip Patch Antennas Using Non-Foster Circuits for Compact Controlled Reception Pattern Antenna Array

The global positioning system (GPS) is a useful system in civilian and military applications. However, because of the weak signal, GPS receivers are vulnerable to interference caused by unwanted signals or intentional jammers. To alleviate this issue, a controlled reception pattern antenna (CRPA) array can be employed to adaptively place radiation pattern nulls toward the direction of the signal interference. The performance of the CRPA array improves as the number of antenna elements increases. Therefore, antenna miniaturization is highly desirable for CRPA applications. We designed a compact CRPA array based on seven electrically miniaturized microstrip patch antennas (MPAs) on a 5-inch ground platform. We used a non-Foster matching circuit to match efficiently miniaturized MPAs on an FR-4 substrate. Experimental results show that the non-Foster matching circuit significantly improves such elements of antenna performance as return loss and antenna gain. In addition, we confirmed that the mutual coupling of the proposed CRPA array is less than -45 dB.

Realistic GPS Coverage Prediction for Dual-Polarized Controlled Reception Pattern Antennas

Null steering arrays for antijam GPS applications are modeled using dual-polarized antenna elements. Realistic performance is evaluated using the effective carrier-to-noise ratio to determine the percentage of the upper hemisphere, for which GPS satellites are recoverable in the presence of interference. The impact of array size and jammer power level on antijam performance is evaluated, and average results are compared to the literature. The realistic metric is shown to predict higher coverage than previously reported.

Optimum Array Configuration to Improve Null Steering Time for Mobile CRPA Systems

This paper proposes an optimum array configuration to improve null steering time for mobile controlled reception pattern antenna (CRPA) systems. The proposed array consists of a single reference element at the center and nine auxiliary elements arranged in a circular array. The array radius and the vertical positions of the center element are optimized using a genetic algorithm in conjunction with a constrained least-mean-square algorithm. The results demonstrate that the proposed array is suitable for mobile CRPA systems without significant side nulls in satellite directions.

Design of a Small Arc-Shaped Antenna Array with High Isolation for Applications of Controlled Reception Pattern Antennas

This communication proposes the design of an arc-shaped antenna array with high isolation to increase the null depth for controlled reception pattern antenna applications. The array is composed of three identical antennas, and each array element is transformed from a rectangular shape to an arc shape to maximize the distance between antenna edges for isolation improvement. The proposed array is fabricated on a 5.5-inch circular substrate to measure antenna characteristics in a full anechoic chamber and is further evaluated by estimating its null depth in conjunction with the conventional power inversion method. The results prove that the array is suitable to effectively improve the isolation and the null depth at low-elevation angles.

Design of microstrip patch antennas with improved low-elevation gain for CRPA applications

This article proposes the design of microstrip patch antennas to improve low-elevation gain for controlled reception pattern antenna (CRPA) applications. The proposed antenna consists of a main resonant patch and a subpatch that are electromagnetically coupled with each other to operate as a two-element array whose bore-sight direction points toward low-elevation angles. The array factor is then enhanced by inserting a ceramic substrate with a high dielectric constant to maximize the electrical distance between the patches. As a result, the average gain at θ = 75° is enhanced by 1.2 dB, which demonstrates that the proposed antenna is suitable to be used for the individual elements of CRPA arrays with the improved radiation gain at low-elevation angles. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:170–174, 2016

Improvement of Pattern Null Depth and Width Using a Curved Array With Two Subarrays for CRPA Systems

This communication proposes a curved array split into two subarrays to improve the pattern null depth and width for controlled reception pattern antenna (CRPA) systems. The proposed array consists of a single reference element at the center and two subarrays that are arranged on a spherical coverture. To consider both signal processing and electromagnetic (EM) perspectives, array patterns are calculated by using a microstrip patch antenna in conjunction with a constraint least-mean-square (LMS) algorithm. The proposed array shows significant improvement in the pattern null depth and width compared to a uniformly distributed circular array.

CRPA array with radiating slots for GPS applications

ABSTRACTThis letter proposes the design of a slot‐loaded controlled reception pattern antenna) array with ground slot radiators to enhance the radiation gain at low‐elevation angles. The array consists of three microstrip patch antennas that are mounted on a circular ground platform, and rectangular slots are inserted at the outer perimeter of the platform. The effectiveness of the inserted slots is verified by comparing the impedance matching and radiating properties of the array with simulation results. The comparison demonstrates that the low‐elevation gain of the proposed design can be improved by the slots, which results in a broad beamwidth covering most of the upper hemisphere. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1991–1995, 2015

Compact controlled reception pattern antenna for interference mitigation tasks of global navigation satellite system receivers

In this study, a novel compact controlled reception pattern antenna for global navigation satellite system (GNSS) applications is presented. Details of the design and the fabrication are given together with measurement results. The miniaturisation has been achieved by employing a five-element polarimetric array approach, resulting in anti-jamming capabilities for many applications where the antenna size is a major constraint. The antenna has a relatively wide bandwidth around the GNSS L1 band which contains many different GNSS signals. The anti-jamming performance of the antenna with respect to differently polarised jammers as well as its positioning capability are investigated.

재밍대응 5소자 평면 GPS 배열 안테나 설계

Abstract This paper describes the design and analysis of five-element planar array antenna of an anti-jamming satellite navigation system. We propose a design of multi-layer patch antenna for Global Positioning System(GPS) L 1 /L 2 dual bands. The proposed antenna has two ports feeding network with a hybrid chip coupler for a broad bandwidth with Right-Handed Circular Polarization(RHCP). The measurement results show the bore-sight gains of 1.10 dBic(L 1 ) and 0.37 dBic(L 2 ) for the center element. The bore-sight gains of an edge element are 0.99 dBic(L 1 ) and 0.57 dBic(L 2 ). At a fixed elevation angle of 30°, antennas show average gains of 2.08 dBic (L 1 ) and 5.33 dBic(L 2 ) for the center element, and average gains of 0.40 dBic(L 1 ) and 2.09 dBic(L 2 ) for the edge elements. The results demonstrate that the proposed array antenna is suitable for anti-jamming applications.Key words: Anti-Jamming, CRPA(Controlled Reception Pattern Antenna), Patch Antenna, Feeding Structure, Circular Polarization, Array Antenna RGEST)(Agency for Defense Development)UManuscript received February 10, 2014 ; Revised April 3, 2014 ; Accepted April 4, 2014. (ID No. 20140210-024)UCorresponding Author: Seung Mo Seo (e-mail: sms@add.re.kr)