Tapered Slot Antenna Array Research Articles

Performance analysis of TSA array with elliptical patch

AbstractA compact microstrip to substrate integrated waveguide transition feed tapered slot antenna array (1 × 4) with the elliptical patch is proposed and analyzed. The new approach is presented, employing a parasitic patch in the flared aperture to generate more radiation in the end-fire direction and improve field coupling between the arms. It boosts gain while maintaining overall size and low-frequency performance without using electrically thin dielectric substrates. To validate the designed approach, the proposed structure is fabricated and measured. The measured results show that the array provides impedance bandwidth of 40%, peak measured gain of 9.14 dBi, and radiation efficiency is 90% over the 8.5–12.5 GHz frequency band. A four-way feed network is also fabricated with the insertion loss of −6 ± 0.9 dB; the reflection coefficient is below −15 dB over the desired frequency range and only ±4° phase imbalance. The overall dimension of antenna array is 50 × 54 × 0.813 mm3 or ~1.6λ × 1.8λ × 0.027λ at 10 GHz.

Self‐decoupled tapered slot antenna using defected radiator structure

A self-decoupled tapered slot antenna (TSA) by rejecting the coupling wave is proposed in this paper. Such TSA arrays have high isolation without introducing additional decoupling structures. And compared with the reference TSA, the self-decoupled TSA is obtained by the defected radiator structure, which is etched with multiple continuous cross grooves on the two fins of TSA. The reason why the defected radiator structure can be decoupled is that it has a band-stop characteristic within the operating frequency band of the TSA. The TSA with and without the defected radiator structure is studied that the TSA with defected radiator structure achieves ultra-wideband decoupling from 3 to 11 GHz. Moreover, the gain of the self-decoupled TSA is improved at most frequencies. A prototype of the self-decoupled TSA and the reference TSA are fabricated and measured. An excellent agreement between simulated and measured results is obtained. The isolation level of the self-decoupled TSA improves by a maximum of 12 dB at 6 GHz. The mutual coupling is reduced by 1 to 12 dB over the entire operating frequency band. In addition, the peak gain of the self-decoupled TSA is improved by up to 1.5 dBi.

Design of an Active Beam-Steering Array With a Perforated Wide-Angle Impedance Matching Layer

In this communication, a tapered slot antenna array with a perforated wide-angle impedance matching (WAIM) layer is studied for active beam steering. To achieve the wide-angle beam scanning characteristic, a tapered slot antenna is used in the array antenna design. For active impedance matching in a wide beam-steering angle, a thin dielectric type of WAIM is introduced, and an optimal WAIM characteristic is realized by changing the effective dielectric constant by adding an air hole to the WAIM. To verify the characteristics of the designed antenna, a 16×16 array is fabricated and measured. The fabricated array shows active S-parameter characteristics of less than -9.13 dB during E-plane scanning and -9.31 dB during H-plane scanning when the beam is steered up to 70° on both planes. It was also confirmed that when the beam is steered to 70°, no scan blindness or grating lobes occur within the operating frequency.

A Broadband High Gain Tapered Slot Antenna for Underwater Communication in Microwave Band

A broadband high gain Tapered slot antenna array for under water communication is presented in this paper. The procedure to design the unit element antenna is followed by applying a linear tapered array-slot structure to the conventional Vivaldi antenna; hence the bandwidth, gain and radiation efficiency of the antenna are improved. The proposed antenna array is designed on the low-cost FR4 epoxy substrate material with value of dielectric constant $$\varepsilon _r= 4.4$$ , and loss tangent $$\delta = 0.02$$ . The reduction of the feed line width and location adjustment is used to expand the impedance bandwidth of the proposed antenna. Moreover, the single antenna element is expanded to $$1\times 2$$ , $$1\times 4$$ and $$2\times 4$$ to form an antenna array respectively. The dimensions of the developed array antenna are satisfying the proper impedance matching. The simulated reflection coefficient results confirm that the proposed antenna array achieves an impedance bandwidth of above 55% obtained at 10 dB return loss, the peak realized gain of 10.75 dBi and radiation efficiency of more than 90%. The measured results show a good agreement and hence making the designed antenna array appropriate to work in the underwater communication band.

Broadband antipodal tapered slot antenna array with low mutual coupling and high gain properties

Strong mutual coupling always exists between the elements of the antenna array, thereby affecting its radiation capability. For this problem, an efficient method for suppressing the mutual coupling of array elements and improving the radiation performance of the antenna is proposed. In this study, take the antipodal tapered slot antenna (ATSA) array, for instance, a set of split-ring resonators (SRRs) unit cells is incorporated into the design to reduce leakage of the side walls at first. With the adding of SRRs, the mutual coupling in the entire operating frequency band (1.4-10 GHz) gets reduced, and the maximum reduction of 35 dB can be achieved. In addition, in order to compensate for the gain reduction caused by the isolation material, the grooves and semi-circular dielectric lens were introduced to enhance the low- and high-frequency gain, respectively. The gain of the proposed ATSA array can be improved by ~3.2 dB. At last, the proposed ATSA array has broadband, high gain with lower mutual coupling properties. This decoupling and gain-enhancing mechanism can be applied to other antenna designs.

Golden angle‐inspired design of massive MIMO tapered slot array with less correlation for 5G lower band applications

In this article, for the first time, we come up with a nature-inspired MIMO antenna configuration that could provide less correlated wireless channels for 5G lower band (3000-4200 MHz). Essentially, the cross-correlation among the antenna elements is reduced by incorporating the concept of golden angle into a cylindrical configuration of tapered slot antenna array. The golden angle helps in arranging the end-fire radiating tapered slot antennas (TSAs) in such a way that there will not be any spatial overlap among the radiation fields of the individual antenna elements. The idea is validated with 24 TSA elements placed in a cylindrical fashion. The envelope correlation coefficient (ECC) is calculated from the simulations in ANSYS HFSS and verified with measurements. The ECC value is found to be less than 0.01 in the range of 3 GHz to 4.25 GHz. The impedance matching and mutual coupling between the elements are found to be very good in the above-mentioned frequency range from the simulations and measurements. It is believed that the application of golden angle concept to MIMO antennas would open up the windows for implementation of dense massive MIMO.

Wideband Circularly Polarized Antipodal Curvedly Tapered Slot Antenna Array for 5G Applications

This paper presents and characterizes a novel high gain circularly polarized (CP) antenna array for 5G applications. The array element is an antipodal curvedly tapered slot antenna (ACTSA) generating circularly polarized field. The CP ACTSA fed by substrate integrated waveguide (SIW) is convenient to integrate with substrates. By introducing two sheet metals on the two sides of the rectangular Rogers 6002 substrate, an impedance bandwidth of 18.2%, a wide 3-dB axial ratio (AR) bandwidth of 16.9%, and stable gain of 8 ± 0.6 dBic over the operating band are achieved. By employing the proposed CP ACTSA as radiating elements, a 4 × 4 high-gain wideband antenna array is proposed for 5G $E$ -band and $W$ -band millimeter-wave applications. Fabrications are carried out using wire cutting electrical discharge machine and print circuit board process, which have advantages of low cost. The whole feeding network is realized by SIW with low insertion loss at millimeter-wave band. Benefiting from the wide impedance and AR bandwidth of the new antenna element, good impedance matching and AR characteristics can be achieved over the whole working frequency band from 81 to 95 GHz by this antenna array. Gain up to 18.5 ± 1.3 dBic is also obtained.

High gain dielectric loaded exponentially tapered slot antenna array based on substrate integrated waveguide for V-band wireless communications

The conception of substrate integrated waveguide (SIW) technology and exponentially tapered slot (ETS) antenna are together used to design a high gain, and efficient planar dielectric loaded antenna for V-band wireless communications. SIW is used to feed the proposed antenna. To increase the gain of the antenna, a dielectric loaded portion is used in front of the antenna and works as a dielectric guiding structure.The dielectric loaded ETS antenna and compact SIW feed are fabricated on a single substrate, resulting in low cost and easy fabrication. The antenna with elliptical shaped dielectric loaded is fabricated using printed circuit board process. The measured gain of the single element antenna is 10.2dB, while the radiation efficiency of 96.84% is obtained at 60GHz. The Y-junction SIW power divider is used to form a 1×2 array structure. Measured gain of the 1×2 array antenna is 11.2dB, while the measured radiation pattern and gain are almost constant within the wide bandwidth of the antenna.

A Novel Compact Wideband TSA Array for Near-Surface Ice Sheet Penetrating Radar Applications

A novel compact tapered slot antenna (TSA) array for near-surface ice sheet penetrating radar applications is presented. This TSA array is composed of eight compact antenna elements which are etched on two 480mm × 283mm FR4 substrates. Each antenna element is fed by a wideband coplanar waveguide (CPW) to coupled strip-line (CPS) balun. The two antenna substrates are connected together with a metallic baffle. To obtain wideband properties, another two metallic baffles are used along broadsides of the array. This array is fed by a 1 × 8 wideband power divider. The measured S11 of the array is less than -10dB in the band of 500MHz-2GHz, and the measured gain is more than 6dBi in the whole band which agrees well with the simulated results.

PCB-Based Prototyping of 3-D Micromachined RF Subsystems

A stacked printed circuit board (PCB) approach for prototyping 3-D microfabrication enabled millimeter and submillimeter wave components and subsystems is proposed. To demonstrate this approach, a 4 to 8 GHz two element tapered slot antenna array with integrated rectangular coaxial 90 ° hybrid, and its stand-alone elements, are designed and fabricated. Measured subsystem results show properly formed radiation patterns, realized gain from 9 to 11 dBi, and 3-dB beamwidth from 30 ° to 45 °. Excellent agreement between simulations and measurements of individual components and the full subsystem as well as outcomes of a tolerance study and comparison to a Ka band micromachined subsystem confirm suitability of the proposed approach for fast, low-cost prototyping of 3-D micromachined rectangular coaxial components and subsystems.

On the Relationship Between Multiple-Scattering Macro Basis Functions and Krylov Subspace Iterative Methods

A mathematical link is provided between the Krylov subspace iterative approach based on the full orthogonalization method (FOM) and the macro basis functions (MBF) approach based on a multiple-scattering methodology. The link refers to the subspaces created by those methods as well as to the orthogonality conditions which they satisfy. Both approaches are applied to the same method-of-moments (MoM) system of equations that is preconditioned based on a closest-interaction rule, and where blocks of the MoM impedance matrix are compressed using a rank-revealing method. MBF and FOM approaches are compared numerically, with a special attention given to accuracy, for perfectly conducting objects, comprising an array of tapered-slot antennas, spheres and an aircraft. The respective advantages of both methods are briefly discussed and further prospects are given.

A Multibeam Antenna Array Based on Printed Rotman Lens

A compact printable multibeam antenna array is studied in this paper. The antenna system is composed of a printed Rotman lens and an antipodal dual elliptically tapered slot antenna array; both of the two components are studied, respectively, at first, and then integrated on a single printed circuit board to make up the integrated unit of the multibeam antenna array. Measured results of all components are presented.

A NOVEL WIDEBAND ANTENNA ARRAY WITH TIGHTLY COUPLED OCTAGONAL RING ELEMENTS

A novel phased array antenna with wide bandwidth and wide scan angle is presented. The radiating aperture of the phased array consists of periodically and closely spaced octagonal ring elements. Tight capacitive coupling between adjacent elements is realized by interdigitating the end portions of the ring elements. To improve the impedance matching of the individual antenna elements over wide frequency band, a novel impedance matching layer consists of periodic octagonal ring element is subtly designed and placed over the radiating aperture. Both of the radiating elements and impedance matching layer are printed on a flexible membrane substrate with a thickness of 0.04mm. Measured results of a 16-element linear array demonstrate that good impedance matching over a 4.4 : 1 bandwidth can be obtained for beam scan angles within ±45◦ from broadside. As compared to conventional wideband phased array such as tapered slot antenna array, the proposed phased array has the features such as low cost, low profile, light weight, and ease of fabrication.

EXPERIMENTAL ASSESSMENT OF MICROWAVE DIAGNOSTIC TOOL FOR ULTRA-WIDEBAND BREAST CANCER DETECTION

An ultra-wideband microwave imaging system that employs a heterogeneous breast phantom and covers the ultra-wideband (UWB) frequency range (3.1 GHz to 10.6 GHz) is presented. The platform scanning system allows monostatic and bistatic mode of operation. In this work, developed heterogeneous phantoms are used to mimic the realistic breast tissues. A utilized tapered slot antenna array allows for a high resolution hemispherical scan, achieved by rotating the imaged object on a turntable. Full design details of the scanning system and the utilized post-processing algorithm are explained. To validate the reliability of the presented system, the results of several imaging cases, including the challenging low dielectric contrast case, are presented.

Analysis of Large Microstrip-Fed Tapered Slot Antenna Arrays by Combining Electrodynamic and Quasi-Static Field Models

A reduced-order model for large arrays of microstrip-fed tapered slot antennas (TSAs) is presented. The currents on the antenna conductors are modeled by a relatively small number of physics-based macro-domain basis functions through a technique which is known as the characteristic basis function method (CBFM). The array is treated as a metal-only structure, while the wideband microstrip feeds are separately modeled using quasi-static circuit models. It is demonstrated that, even though the dielectric-supported feeds are non-shielded and therefore form an integral part of each radiating antenna element, the feeds can be modeled independently from the strongly coupled antenna elements. Validation of the combined antenna-feed model has been carried out through the measurements of several practically realized TSA arrays, among them a 8 × 7 × 2 dual-polarized array. The results demonstrate good agreement over a large scan range, as well as over a wide frequency band. The polarization-discrimination capabilities of the antenna, when operating in phased-array mode, have been analyzed in the context of radio-astronomical applications.

Scan Blindness of Tapered-Slot Array Optimized with Tapered-Aerosubstrate in the Triangular Elements Grids

Tapered-aerosubstrate is applied to optimize the scan blindness of tapered-slot antenna array where elements are positioned in a triangular grid. The blindness occurs when the steering phase progression in the E-plane is equal to the phase progression of a leaky mode in the structure and could be optimized by the tapered-aerosubstrate which elevates the resonance positions of dominant radiator modes. Character analysis of tapered-aerosubstrate is shown to be agreed well with the compute and experiment results, and scan blindness is moved 12.5% toward the upper frequency.

Study and Design of a Differentially-Fed Tapered Slot Antenna Array

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The results of a parametric study and design of an ultrawideband dual-polarized array of differentially-fed tapered slot antenna elements are presented. We examine arrays of bunny-ear antennas and discuss the capabilities and limitations of differential antenna technology. As we focus on radio astronomical applications, the absence of a balancing-feed circuit not only reduces the first-stage noise contribution associated to losses in the feed, but also leads to a cost reduction. Common-modes are supported by the antenna structure when a third conductor is present, such as a ground plane. We demonstrate that anomalies may occur in the differential-mode scan impedance. Knowledge of both types of scan impedances, differential and common mode, is required to properly design differential LNAs and to achieve optimal receiver sensitivity. A compromise solution is proposed based on the partial suppression of the undesired common-mode currents through a (low loss) balancing-dissipation technique. A fully steerable design up to 45<formula formulatype="inline"><tex Notation="TeX">$^{\circ}$</tex> </formula> in both principal planes is achieved. </para>

Analysis and design of wideband widescan planar tapered slot antenna array

Phased arrays have been required to operate over wide bandwidths and wide scan angle to support multifunction operation in both telecommunication and radar. In response to that need, this study firstly analyses the performance of the connected planar tapered slot antenna array and finds that the mutual coupling is essential and has good effect in wideband antenna array design. Then the authors design a wideband widescan planar tapered slot antenna array system with novel dual-parabola tapered slot antenna elements and feed network. This array can operate from 1.6 to 9 GHz and scan angle up to 45°. Both simulation and measurement results are shown to certificate the performance of the proposed antenna array.

Design of broadband array elements based on neural network and genetic algorithm

Coupled artificial neural network (ANN) and genetic algorithm (GA) models are developed for the design of broadband tapered slot antenna array elements. The ANN is employed to establish the complicated relationships between the key array performance indicator, i.e. active reflection coefficient, and its element parameters. The trained ANN models are combined with the GA to optimise the element parameters for a given operating frequency band without using time-consuming EM simulators. Optimisation results show the developed ANN-GA model can retain the accuracy obtainable from EM simulators and exhibit high computational efficiency.

Segmented analysis of a finite planar ridged tapered slot antenna array for wideband phased array

AbstractThe segmented analysis method of a finite planar ridged tapered slot antenna (RTSA) array is presented to develop a wideband phased array with a triangular lattice. The RTSA array is segmented into two‐parts with a feeder and the arrays of tapered slot antenna (TSA) and these scattering parameters are analyzed respectively. This proposed method gives the merit of a great reduction of computational cost. To verify the advantage of this method, we build the numerical model of only one feeder and dual polarized arrays of TSA with 10 × 12 elements. The measured results of the fabricated array meet the design goals of 3:1 bandwidth, scan volume of ±45°, active VSWR (AVSWR) below 3:1. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1140–1143, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23314