Dual Linear Polarization Research Articles

Wideband, low profile P‐ and Ku‐band shared aperture antenna with high isolation and low cross‐polarisation

This study describes the design of a wideband, low-profile shared aperture antenna operating at P-band and Ku-band. This antenna operates with dual-linear polarisation in P-band and single-linear polarisation in Ku-band. In this antenna design, it consists of one P-band microstrip patch antenna and an 8 × 8 Ku-band aperture-coupled patch array. The antenna covers from 330 to 420 MHz in the P-band and from 14.27 to 16.20 GHz in Ku-band with |S11| better than − 10 dB, which translates to 24 and 13% bandwidth in P- and Ku-band, respectively. The overall height of the antenna is about 80 mm, approximately 0.09λ at the lowest frequency. The cross polarisation is better than − 20 dB in the P-band and − 26 dB in the Ku-band. There is virtually no coupling between the P- and Ku-band. The measured gain varies from 6.5 to 7.5 dBi in the P-band and from 22.5 to 23.4 dBi in Ku-band.

Continuously Polarization Agile Antenna by Using Liquid Crystal-Based Tunable Variable Delay Lines

In this paper, a polarization agile planar antenna is presented by using tunable liquid crystal (LC) material. The antenna includes a 2 × 2 dual-fed microstrip patch array and two separate feeding networks for each feeding of the dual-fed antenna. The polarization state of the antenna can be controlled continuously between dual linear and dual circular polarizations depending on a differential phase shift between the antenna feedings. The feeding networks are implemented in inverted microstrip line topology with the liquid crystal material as a tunable dielectric. A desired differential phase shift is obtained between the feeding networks by tuning the LC material. Thus, no additional tunable components are required according to proposed antenna topology. Additionally, owing to the continuous tuning of the LC material, any polarization state between the circular and linear ones are achievable. The antenna prototype is designed at 13.75 GHz. The measured return losses are greater than 10 dB in a frequency range of 13.5 to 15 GHz for different polarization states. Far-field pattern measurements are performed, which confirm the continuous tuning of the antenna polarization. Specifically, the measured antenna patterns are presented for ±45° linear and right-handed circular polarizations. The prototype can be fabricated in a larger size with more radiating elements and can be efficiently scaled for higher operating frequencies at the Ka-or W-band since the LC material features even lower dielectric losses at higher frequencies.

High-Isolation XX-Polar Antenna

A new configuration of the dual-band and dual-polarized antenna is presented, which is fed by aperture coupling for the existing mobile communication systems working over 870-960 MHz (GSM) and 1710-2180 MHz (DCS/UMTS) frequency band. XX-Polar antenna stands for an antenna with dual-band and dual linear slant polarization. In this paper DU band stands for DCS/UMTS band. Measurement results show that the proposed antenna yields good broadside radiation characteristics including symmetric radiation patterns, low cross-polarization level ( ; 20 dB) and high isolation (>; 30 dB) at both bands. The designed antenna has an impedance bandwidth of 20.4% (790-970 MHz) for VSWR <; 1.5 in the lower band and 29.3% for VSWR <; 1.6 (1630-2190 MHz) in the upper band. The measured average gains are about 9.3-10.2 and 8.6-10 dBi in the lower and upper band, respectively. It is also promising for array antenna in various wireless systems.

Investigation of factors contributing depolarization in offset reflector antenna and trimmed-reflector offset parabolic antenna with lower cross-polarization

This article outlines impact of various factors on cross-polarization characteristics of offset reflector antenna for communication spacecraft with smaller sized bus at C band. Effects of different parameters are considered in rigorous analysis of the antenna. Measured and predicted performances are found in agreement. To fulfill specific requirement of higher edge-of-coverage gain (>26 dBi) and higher cross-polarization discrimination (XPD > 30 dB) over a wider coverage and dual linear polarization under the imposed constraints, a novel trimmed-reflector offset parabolic antenna (TROPA) is devised. This interesting configuration is obtained by trimming both sides parallel to symmetrical plane of a parabolic offset reflector antenna. Parametric study of trimming distance versus its impact on cross-polarization is also presented. The TROPA acquires wider bandwidth, simplification in its mechanical design and manufacturing, and offers low weight and compactness. It is also shown that trimmed reflector has almost even RF performance in presence of spacecraft body and other antenna. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.

MULTIOBJECTIVE OPTIMIZATION AND DESIGN OF A LUNEBERG LENS ANTENNA WITH MULTIBAND MULTI-POLARIZED FEED-SYSTEM

A general multiobjective optimization and design proce- dure of a Luneberg lens antenna (LLA) with a compact multiband multi-polarized feed-system for a broadband satellite communication terminal is presented. The LLA utilizes a compact multiband feed horn, consisting of an inner dielectric loaded circular horn for the K/Ka-band (dual-circular polarization) and a coaxial waveguide with axially corrugated ∞ange for the Ku-band (dual-linear polarization). Measurements show good agreements with simulations. Moreover, an e-cient multiobjective evolutionary algorithm based on decomposition (MOEA/D) with difierential evolution operator and objective normal- ization technique is flrstly coupled with the vector spherical wave func- tion expansions (VSWE) for the optimal design of a 7-layer 650mm diameter LLA, which provides higher aperture e-ciency at Ku/K/Ka- band simultaneously. The frequency dependence of the LLA is also investigated. Finally, the gain and sidelobe level of a 5-layer design are jointly evaluated and compared with previous works. The pro- posed design procedure provides much better radiation performances and greater design freedom to the designers, as a group of Pareto- optimal LLA solutions can be obtained with just one simulation.

DESIGN, SIMULATION AND MEASUREMENT OF A DUAL LINEAR POLARIZATION INSENSITIVE PLANAR RESONANT METAMATERIAL ABSORBER

In this paper, we introduce a highly electric-fleld-coupled (ELC) metamaterial planar absorber in microwave frequency range. The structure is a one layer dual linear polarization insensitive absorber, which is designed by utilizing properly arranged resonant structure with orthogonal polarization sensitivity. In addition, this metamaterial absorber operates over a wide angular range, from 0 - to 65 - with more than 95% absorption peak. Absorption peak occurs at the frequency of 10.05GHz with 98% magnitude with FWHM about 5%. In addition to simulation, the theoretically results are verifled by measurement, and test results generally agree with simulation ones. The dielectric spacer loss tangent for higher absorption peak and broader bandwidth has been investigated too, and the optimum value for the best absorber structure performance has been obtained.

A DUAL-BAND DUAL-POLARIZED MICROSTRIP ARRAY ANTENNA FOR BASE STATIONS

This paper presents a new dual-band, dual-polarized 1£4 antenna array design for telecommunication base station. One of the bands covers global system for mobile communication (GSM) band, while the other covers both digital communication system (DCS) and universal mobile telecommunication system (UMTS) bands. The antenna is based upon an aperture stacked patch layout and incorporates a simple and novel dual-layered feeding technique to achieve dual polarized radiation. For feeding the array elements, a corporate feed network is used. In order to achieve appropriate matching in both bands, a three-section Chebyshev transformer has been designed. The proposed antenna shows good port decoupling, less than i30dB for dual linear polarization over its operating bands. Peak antenna gains about 11dBi and 11.6dBi have been obtained for lower and upper bands, respectively. The efiort was directed toward the design of a single standalone dual-polarized antenna to cover all three bands.

Bunny Ear Combline Antennas for Compact Wide-Band Dual-Polarized Aperture Array

A bunny ear shaped combline element for dual-polarized compact aperture arrays is presented which provides relatively low noise temperature and low level cross polarization over a wide bandwidth and wide scanning angles. The element is corrugated along the outer edges between the elements to control the complex mutual coupling at high scan angles. This produces nearly linear polarized waves in the principle planes and lower than -10 dB cross polarization in the intercardinal plane. To achieve a low noise temperature, only metal conductors are used, which also results in a low cost of manufacture. Dual linear polarization or circular polarization can be realized by adopting two different arrangements of the orthogonal elements. The performances for both mechanical arrangements are investigated. The robustness of the new design over the conventional Vivaldi-type antennas is highlighted.

High-Isolation X-Polar Antenna

Antennas with dual linear slant polarization are necessary for modern personal communication base station applications. X-Polar antenna stands for an antenna with dual linear slant polarization. The most significant feature of the proposed antenna is high isolation between two different polarizations. The structure used here includes a reflector, a U-shaped strip, a cross-slot, a patch, and a director. Simulation and measurement results show minimum 30 dB isolation between the two polarizations. This structure yields half-power beamwidth (HPBW) of 65°, a cross-polarization level of less than -15 dB, and a voltage standing wave ratio (VSWR) of better than 1.5. This structure is useful for dual-band and dual-polarized applications such as the Global System for Mobile communications (GSM) and the Universal Mobile Telecommunications System (UMTS) frequency range.

A Planar Dual Linear-Polarized Antenna With Integrated Balun

This letter presents a miniature <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</i> -band (770-1700 MHz) crossed bowtie antenna with integrated microstrip matching network and balun. Curved bowtie edges are employed for miniaturization and maintain nearly constant input impedance. The antenna provides dual linear polarization with greater than 5 dBi gain and exhibits a return loss greater than 10 dB when placed 1.5 in (λ/10 at 770 MHz) above a ground plane.

DESIGN OF DUAL-BAND MICROSTRIP REFLECTARRAY USING SINGLE LAYER MULTIRESONANCE DOUBLE CROSS ELEMENTS

A multiresonance double cross element is used to design a dual-band reflectarray with dual linear polarization. The proposed element has a single conductive layer structure which makes it easy to manufacture. The results presented in this paper show that the mutual effect between the elements of the two bands is negligible. Hence, it is easy to achieve the phase compensation for each band separately. The simulated and measured results for an element designed to cover the X- and K-bands have confirmed the suitability of the proposed element to build a dual-band reflectarray.

Rectenna design and optimization using reciprocity theory and harmonic balance analysis for electromagnetic (EM) energy harvesting

A rectenna design methodology combining electromagnetic (EM) simulation and harmonic balance (HB) analysis is presented. It consists of applying reciprocity theory to calculate the Thevenin equivalent circuit of the receiving antenna and optimizing the rectifying circuit parameters using HB analysis. The method is demonstrated by designing a 2.45-GHz rectenna based on a square aperture-coupled patch antenna with dual linear polarization. A compact implementation is achieved by etching a cross-shaped slot on the patch surface leading to a 32.5% patch side reduction. Voltage-doubling circuits convert the received RF power from each port to dc permitting the rectenna to receive arbitrarily polarized signals. The circuit is optimized for low input power densities and a simulated maximum efficiency of 38.2% was obtained for 1.5 ${\hbox{uWcm}}^{-2}$ input RF power density at 2.43 GHz.

Development of Low Profile Cavity Backed Crossed Slot Antennas for Planar Integration

Single fed low profile cavity backed crossed slot antennas for dual frequency dual linear polarization and circular polarization applications are first presented in this paper. By employing the substrate integrated waveguide (SIW) technique in the antenna designs, the low profile backed cavity structure can be realized by using only a single layer of low cost printed circuit board (PCB) substrate. A single grounded coplanar waveguide (GCPW) is employed as the feeding element to excite the TE 120 and TE 210 modes in the SIW cavity. A crossed slot structure is used as the radiating element in order to radiate the desired dual linearly or circularly polarized wave. From the measurement results, it is seen that these novel antennas retain the advantages of conventional metallic cavity backed antennas, including high gain, high front-to-back ratio (FTBR), and low cross polarization level (CPL). Furthermore, the proposed antennas also possess the advantages of low profile, light weight, low fabrication cost, and easy integration with planar circuits.

Broadband Dual Linear Polarized Antenna for Statistical Detection of Breast Cancer

A broadband planar antenna capable of dual linear polarization is designed to be used for the detection of breast tumors. This antenna along with a breast model is simulated using the Ansoft HFSS v10.1. The S-parameters are used as input to Artificial Neural Networks for data processing to investigate the effect of polarization on the statistical detection. Using a dual polarized antenna allowed the calculation of all vertical and horizontal co- and cross-polarizations. The numerical results show that using polarizations parallel to the tumor's major axis increases the likelihood of tumor detection.

A High-Isolation, Wideband and Dual-Linear Polarization Patch Antenna

The design of a dual-polarization stacked patch antenna to be used in GSM-UMTS base station arrays is presented. The patch shows a high matching level in a broadband and isolation between elements that make it a suitable radiating element for base station arrays. Moreover, the most relevant achievement of this element is the isolation between the two polarization ports of the same element in the antenna operating bandwidth. A prototype has been manufactured and measured. The measurements, that match the design objectives, are also presented.

Broadband Polarization Diversity Base Station Antenna for 3G Communication System

Antennas with dual linear slant polarization over a wide band are necessary for modern personal communication base-station applications. A ±45° polarization diversity antenna element constructed by novel umbrella-shaped dipoles is presented in this paper. The antenna has a half-power beam width of 63° ± 5° in the horizontal plane by designing a reflector over a bandwidth of 1710 to 2170 MHz, which covers not only 3G frequency band (1920–2170 MHz) but also DCS band (1710–1880 MHz) and PCS band (1850–1990 MHz). In addition the worst-case isolation between polarizations is 30 dB and the front-to-back ratio is more than 30 dB over the above frequency band.

Erratum: Symmetry, XPD, and port isolation in an ACMPA array with dual linear polarization

AbstractOriginally published Microwave Opt Technol Lett 49: 1722–1727, 2007. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2886, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22803

Symmetry, XPD, and port isolation in an ACMPA array with dual linear polarization

AbstractAperture coupled microstrip patch antennas (ACMPA) are very convenient array elements for designing high directivity planar antennas. Dual polarization ACMPA arrays for Direct Broadcasting Services (DBS) have the problems of low cross‐polar discrimination (XPD) and port isolation. In this work, the relationships between feed symmetry and the values of XPD and Port Isolation are investigated. A particular feeding structure, which optimizes XPD and Port Isolation, is proposed. An 4 × 4 array that operates at the European DBS frequencies has been designed, built, and measured to demonstrate the effectiveness of the proposed structure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1722–1727, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22516

UWB Dual-Linear Polarization Dielectric Horn Antennas as Reflector Feeds

An ultrawide bandwidth (UWB) dielectric horn antenna (DHA) design is presented. This DHA design provides dual-linear polarization with similar Eand H-plane patterns and a near-constant beamwidth from 2 to 18 GHz. The fixed phase center makes it an excellent candidate for feeding a reflector. The DHA is composed of a resistively terminated broadband field launcher, a solid dielectric horn body, and microwave absorbers for suppressing lateral waves and back lobes. Desirable beamwidth can be achieved by choosing a specific horn angle. A design example that shows a beam aspect ratio (BAR) close to one and approximately 110-degree 10-dB beamwidth is presented. The measured results are validated by full-wave simulations with the finite difference time domain (FDTD) method

Diversity performance of a dual-linear polarisation suspended gap-coupled microstrip antenna

The diversity performance of a dual-linear polarisation microstrip antenna is investigated across the broad operating bandwidth. As an example, the suspended gap-coupled microstrip antenna has been chosen for the study. Using a ±45° polarisation scheme, the probe-fed square main patch, surrounded by four parasitic patches on its radiating and non-radiating sides, is suspended above the ground plane. The simulated and measured impedance as well as the radiation performance are given. The diversity performance is evaluated in terms of the far-field coupling, output power correlation as well as the diversity gain in a non-fading channel. From the analysis performed at three primary frequencies, the diversity performance has been found to vary across the impedance bandwidth. It is shown that other than the environment, the radiation characteristics of the antenna have a considerable effect on the diversity gain.