Slot Array Antenna Research Articles

Моделирование щелевой двухэлементной антенны со связанным питанием

A micro-strip fed slot antenna array for the ISM band was built using standard formulas for calculating various antenna parameters. Half power beamwidth 57°, throughput about 7.7%. This is obtained by matching the impedance and the high level of the surface waves. To expand the bandwidth, a direct-coupled power was used, which provides the largest bandwidth, is fairly easy to model, and has low spurious radiation. A directivity of 2.01 dB was achieved. This is a fairly high figure, although an increase in directivity can also be obtained by using a different material and thickness of the substrate. HFSS software examines and analyzes antenna characteristics, including voltage standing wave ratio, return loss, and far-field radiation patterns.

Design and characterization of a circularly polarized microstrip-line-fed slot array antenna for S-band applications

A 2×2 slot array antenna fed by microstrip line for circular polarization operated in the S band frequency range is designed in this paper. Single cross slot with single port feed as well as dual port feed is taken into consideration for realizing circular polarization and combining these two processes, the slot array is designed with single feed for circular polarization. The antennas are designed on a Teflon glass fiber substrate of thickness 0.8 mm. The slot array dimension is 120×142×1.636 mm<sup>3</sup>. Smith chart of single cross slot antenna with single feed as well as dual feed has a dip at 2.69 and 2.53 GHz respectively indicate the capability of realizing circular polarization in the S band frequency range. The return loss of the slot array antenna is -58 dB shows good input impedance matching of the antenna. A dip in the smith chart of the slot array shows circular polarization near 2.4 GHz ensuring wireless applications as well. Axial ratio is found to be less than 1 dB in the resonance frequency. The impedance bandwidth percentage of the slot array antenna is 12.24%. The simulation is done by using keysight advanced design system (ADS) software.

Bidirectionally-Fed Slow-Wave Substrate-Integrated Waveguide Monopulse Slot Array Antenna With Gain Enhancement

Bidirectionally-Fed Slow-Wave Substrate-Integrated Waveguide Monopulse Slot Array Antenna With Gain Enhancement

A Substrate-Integrated Cavity-Backed Slot Antenna Array in Y-Band

A Substrate-Integrated Cavity-Backed Slot Antenna Array in <i>Y</i>-Band

Analysis of Wide‐Angle Scanning of High‐Power Microwave Waveguide Slot Array Antenna

In the design of high‐power microwave (HPM) waveguide array of longitudinal shunt slots, the mutual coupling of slots in different waveguide can badly decrease the capability of wide‐angle scanning of array. An L‐band HPM waveguide array of longitudinal shunt slots is designed. The choke groove was designed to restrain the mutual coupling of slots of the HPM array antenna. The result of simulation verified that the scanning angle with the gain of antenna decreased of 3 dB of array without choke groove structure is only 25°, and that is 35.0° with choke groove structure. The wideband of active reflection of array can be improved by the choke groove structure. The result of experiment also verified that the slot array antenna provided 30° beam steering with a gain reduction of 1.8 dBi and the power‐handling capacity of the array with the choke groove is greater than 1.5 GW with width of pulse of 42 ns. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Design and Performance Evaluation of Cavity-Backed SIW Antenna for Monopulse Applications

The design of a cavity-backed substrate integrated waveguide (SIW) dual-plane antenna for monopulse application is presented in this publication. The primary objective is to create a four-element circularly polarized cavity-backed slot antenna array that is compact and highly efficient. Two antenna subarrays are utilized to develop a complete analysis, design, and implementation of an antenna, and each antenna element can be used as an independent antenna for monopulse applications. The antenna element is made up of two square ring slot antenna components, a power divider, and a feed point. To produce sum and difference signals, the feed point of each antenna element can be connected to one of the input ports on a monopulse comparator. The antenna's performance at 10 GHz was assessed regarding radiation pattern, gain, return loss, bandwidth, axial ratio, and efficiency. A high-frequency structure simulator (HFSS) simulates a complete planar and compact SIW structure with a footprint of 61.6 mm x 58.1 mm. With a permittivity of 3.55 and a thickness of 1.524 mm, an antenna is manufactured using a photo-lithographic process on a single-layer Rogers RO4003 substrate. As per experimental findings, the antenna has a return loss of -40.17 dB, an RL bandwidth of 395 MHz, a gain of 13.11 dB, an axial ratio of 2.97 dB, and an efficiency of 89.85% at a frequency of 9.92 GHz. Experimental findings reveal exceptional performance parameters for the designed antenna, which can be used for monopulse applications at 10 GHz.

High Gain Slot Array Antenna at 110 GHz Based on Computer Numerical Control.

This paper presents a waveguide-slot antenna to generate a radiation beam with high gain fed by a low-loss feeding network at 110 GHz. The proposed antenna consists of a compact eight-way power divider and a waveguide-slot array. The eight-way power divider provides equal-amplitude and alternative-phase excitation for the slot array, and each of them supports two waveguides. The integral structure is implemented by two layers with a channeled substratum and a slotted superstratum. To verify the proposed slot array, the designed array is fabricated with computer numerical control (CNC) milling and measured. The measured peak gain of the designed antenna is 32 dBi at 110 GHz. The proposed antenna with a simple structure provides a promising solution to develop high gain antenna in upper millimeter-wave and sub-terahertz (THz) applications.

Development of a Broadband and High-Gain Circularly Polarized Array of Multilayer Slot Antennas for X-Band Wireless Communication Networks

This paper presents a wideband cavity-backed slot antenna array designed for X-band wireless communication systems. The antenna element consists of a circular slot combined with a cross-slotted patch; both are fed by an L-shaped microstrip line through proximity coupling to extend the impedance bandwidth and gain. The reduction of beam squint in the radiation patterns, caused by the asymmetric feed line, is achieved through intelligent optimization of the dimensions and position of the cross slot on the patch. Additionally, a back cavity is included to provide unidirectional radiation and enhance gain. The antenna exhibits right-hand circularly polarized (RHCP) radiation patterns with high gain over a wideband frequency range. To further improve the axial ratio (AR) bandwidth and gain, the antenna is utilized in a 2 × 2 array configuration with a sequential rotation feed network. The overall dimensions of the proposed array are 1.42 λ 0 × 1.42 λ 0 × 0.45 λ 0 , where λ 0 represents the wavelength at the center frequency of 10 GHz. The fabricated array is then tested, and the measurements show an impedance bandwidth of 60% (7 GHz-13 GHz) with S 11 &lt; − 10 dB, a 3 dB AR bandwidth of 42% (7.45-11.65 GHz), and a peak gain of 11.14 dB. The simulated and measured results exhibit good agreement, validating the effectiveness of the design.

A Substrate Integrated Waveguide Slotted Antenna

Introduction. Slotted waveguide antenna arrays are widely used across centimeter- and millimeter-wavelength ranges due to numerous advantages, including their good directional properties, compact dimensions, flat shape, convenience of power supply, and high efficiency. At the same time, the current trend toward miniaturization of electronic devices and their integration requires new solutions, such as the development of devices based on wave-guides integrated into the substrate (Substrate Integrated Waveguide – SIW).Aim. To simulate a SIW-based slotted antenna with characteristics similar to those of a conventional antenna array based on a hollow metal waveguide.Materials and methods. The Ansys HFSS software was used to simulate the structure under study and to carry out electro-magnetic modeling and analysis of its directional properties. The energy method was used to determine the coordinates of longitudinal slots on the wide wall of the SIW waveguide. Macros were developed in the Visual Basic Scripting Edition language to automate routine operations for creating and deleting objects of the same type when constructing a model. The Arlon AD300C microwave material was used to manufacture a printed version of the SIW waveguide.Results. The process of developing a SIW slotted antenna was carried out in the following stages: construction of a reference model based on a hollow metal waveguide followed by creating a transition model based on a waveguide completely filled with a dielectric and the final SIW-based model. At each stage, the radiation pattern was monitored to obtain the directional properties of the SIW slotted antenna with characteristics identical to those of an antenna based on the reference hollow metal waveguide.Conclusion. A SIW slotted antenna with the required characteristics was simulated and tested in the Ansys HFSS environment. Such an antenna employs one of the main advantages of the SIW technology, i.e., the possibility of integrating all components on a single substrate, including antenna arrays, passive components, and active elements. This approach provides the basis for reducing the size of microwave devices and their miniaturization.

Sidelobe Level Reduction for a W-Band SIW Slot Array Antenna by Only Reversing Offset Direction of Partial Slots

Sidelobe Level Reduction for a W-Band SIW Slot Array Antenna by Only Reversing Offset Direction of Partial Slots

Hybrid Sidelobe Recognition Method Using Boresight Error and Quadrant Signal Difference for Monopulse Array

In this paper, a sidelobe recognition method using boresight error and quadrant signal difference for a monopulse array is proposed. A conventional sidelobe recognition method compares the difference between the sum and delta channels. This method works well for the azimuth and elevation planes. However, the method is prone to many errors in the diagonal region of the two-dimensional plane. To overcome this problem, a method to calculate the deviation of the boresight error difference with different frequency combinations and a threshold to identify the sidelobe is proposed, and the method is validated to significantly reduce the error region. If a four-quadrant signal can be extracted separately, the signal deviation can be calculated and compared with the threshold, and the error region can be further reduced. The effects of each margin and bandwidth on the recognition performance are analyzed, and a slot array antenna is simulated to assess the method’s effectiveness.

A high-order TE50 mode waveguide with single mode transmission property and its application in slot array antenna

Conventional array antenna techniques contain various feeding networks, such as T-junction power dividers, phase dividers, and baluns. To feed a relatively large array, one can cascade the traditional T-junction power dividers, resulting in the increase of design complexity. In this paper, an overmoded waveguide supporting the single mode propagation of TE50 mode, is presented. Since TE50 mode can be separated into five TE10 modes with equi-amplitude and opposite phase properties, it is advisable to distribute the input signal flexibly and decrease the cascading of the T-junctions for the traditional feeding networks. To actualize a TE50 mode waveguide, several rows of metallic blocks acting as metamaterial are periodically loaded inside an overmoded waveguide to tailor the dispersion of the waveguide modes and yield the proposed mode bandgaps. Considering the Bloch theory, parts of the undesired waveguide modes are not supported inside the metamaterial and will be removed by these bandgaps. In addition, central feeding method is used to suppress the unwanted modes further in light of mode mismatch. As a proof-of-concept, we drilled the slot array on the top of the overmoded waveguide directly and give rise to a pencil beam radiation along the broadside with 15–17 dBi realized gain among 9.4–10.6 GHz, which demonstrates the stable feeding ability of TE50 mode.

A novel SW-ESIW slot antenna and its applications in millimeter-wave array design

A novel structure of slot antenna with high gain and compact size for millimeter-wave (mmW) applications is proposed. This is the first attempt to apply slow-wave substrate integrated waveguide (SW-ESIW) to the field of antennas and their arrays. Two slot antenna arrays were designed, fabricated and measured. The measured results are in agreement with the simulation. The removal of dielectric substrate improves the radiation gain. At the same time, the slow wave effect, by means of physical separation of electric and magnetic fields, decreases both the lateral and longitudinal dimensions of the antenna. The SW-ESIW slot antenna can achieve miniaturization while retaining the advantages of high gain of ESIW. The 1 × 4-slot array shows a measured −10 dB bandwidth of 16% (30.5–35.8 GHz) with a measured maximum gain of 11.69 dB. The 4 × 4-slot array achieves a measured −10 dB bandwidth of 7.6% from 31.6 to 34.1 GHz with a measured peak gain of 18.75 dB. In addition, during the operating band, the radiation pattern is stable. Compared with the previously structures, the proposed SW-ESIW antenna structure has a better trade-off between gain and footprint. It can be flexibly adjusted to adapt to different requirements. These performances ensure that the antenna array based on the proposed structure is a promising candidate for millimeter-wave wireless applications including the fifth-generation mobile communications.

3D metal printed slot antenna array with high gain and enhanced bandwidth using triple‐mode sine corrugated cavity resonator

AbstractThis letter proposes a class of sine corrugated cavity resonators (SCCR). The SCCR can present slow‐wave features and provide dual‐mode (TE104 and TE105) wideband responses with reasonable sine period and depth. Based on it, a compact high‐gain bandwidth‐enhanced SCCR slot antenna array is designed. The high gain is obtained with seven radiation slots and the wideband is achieved due to three modes being utilised. The three modes include the modes of TE104 and TE105 of the SCCR and one feed slot mode. Compared with published works, the desired TE104 and TE105 can be obtained straightforwardly based on SCCR. The standard WR62 waveguide is utilised to feed the antenna. For validation, direct metal 3D printing technology is used to fabricate it with aluminium and copper powders as a comparison. Both measured results were discussed and showed a good agreement with the simulated ones.

Design of a slot array antenna with ultra-wideband low-scattering characteristic

This paper presents a 4 × 4 slot array antenna with ultra-wideband low-scattering characteristic, which integrates a metasurface based on the multielement phase cancellation (MEPC) method. Limited by the characteristics of the slot antenna array, the contradiction between the ideal radiation performance and the requirement of low radar cross section (RCS) has not been well resolved. Therefore, in this paper, a MEPC-based metasurface is designed as the cover-layer of the proposed antenna, which can disperse the reflected energy to more directions without degrading the radiation performance. The proposed antenna operates in a bandwidth of 3.89–4.00 GHz with a maximum gain of 14.3 dBi. Additionally, the 7 dB RCS reduction bandwidth for TE/TM polarization at normal incidence is 5.5–40 GHz (f h / f l = 7.27:1), achieving ultra-wideband out-of-band RCS reduction. Furthermore, low-scattering performance can remain stable at large-angle oblique incidence. To verify the feasibility of the proposed design, a prototype is fabricated and measured for demonstration. The simulated and measured results are in good agreement.

Compact Additively Manufactured Conformal Slotted Waveguide Antenna Array

In this work we present the design and fabrication in metallic 3D-printing of a compact conformal slotted waveguide antenna array operating in the Ku-band. The application objective, although not limited only to this, is the optimisation of an antenna element which by stacking will be able to form a quasi-cylindrical sector. A beamforming network will be used for beam-steering in the elevation plane as coverage in the azimuthal plane is guaranteed by the conformal geometry. The compact design of the antenna element is therefore of great significance. For this reason, a direct feeding scheme by a coaxial connector is adopted. The antenna has been optimized following multiple parametric analyses of its geometrical parameters for the enhancement of the bandwidth, return losses and realized gain. The antenna was fabricated with Selective Laser Melting in aluminium and the experimental results agree well with the numerically calculated ones. The proposed CSWAA exhibits a reflection coefficient below -10 dB, realized gain above 14 dBi, as well as good cross-polarization and side-lobe level over a relative bandwidth of 8%.

Frequency-Scanning Leaky-Wave Array Antenna With Extended Scanning Range for Millimeter-Wave Imaging

In this letter, we propose a frequency scanning leaky-wave array antenna with a significantly increased scanning range. The proposed structure consists of a pair of rectangular waveguide fed leaky-wave slot array antennas that are designed to achieve focusing in the backward and forward quadrants at 26.5 GHz and 23 GHz respectively. A total scanning range of about 73˚ is achieved by the structure simply by changing the frequency. The focusing gain between the backward and forward quadrants varies from 23 dBi to 25 dBi with the operation of the two waveguides separated by exploiting the cutoff region of one waveguide, operating with negative phase constant, and the endfire radiation of the other waveguide, operating with a positive phase constant, allowing the use of a single feed for both waveguides.

Dual-Polarized Wideband Low-Sidelobe Slot Array Antenna for V-Band Wireless Communications

A dual-polarized wideband low sidelobe slot array antenna for wireless communication systems in the V-band is proposed in this work. Taylor distribution is applied with each radiating slot as a tapering unit in both polarizations. A compact 2 × 2 elements subarray is designed to achieve stable amplitude and phase distribution among elements with two sets of integrated compact wideband unequal power dividers for the E- and H-planes inside the subarray. Then, two layers of orthogonally polarized feeding networks with unequal E-plane T-junction power dividers are used to connect the subarrays to two standard waveguides WR-15 as input ports. The prototype of 8 × 8 elements is fabricated and measured in an anechoic chamber. The maximum measured gain is 25.3 dBi and 25.4 dBi for V- and H-polarization, respectively. The overlapped impedance bandwidth is from 57 to 66.4 GHz with reflection coefficiencies below -10 dB, and the isolation between two input ports is around 35 dB. Sidelobe levels of both polarizations are below -22 dB with good agreement with the simulations.

Metallo-Dielectric Millimeter-Wave Huygens’ Quarter-Wave and Half-Wave Plates

A novel metallo-dielectric Huygens’ unit cell is proposed that can be designed to operate either as a quarter-wave plate (QWP) or as a half-wave plate (HWP). The unit cell is based on a single-layer perforated dielectric, with straight (non-metallized) and 45° (metallized) elliptical holes. The novelty of the unit cell is its suitability for millimeter-wave implementation in printed-circuit board (PCB) fabrication due to the absence of metallic patterns of small line widths and gaps. As an example of their applicability, the wave plates are demonstrated in the near-field of 60-GHz band diffusion-bonded slot array antennas. The unit cell operating as a QWP is demonstrated in full-wave simulations and experimentally for linear-to-circular polarization conversion, whereby the combination of a linearly-polarized (LP) antenna and the QWP produces a circularly-polarized (CP) wave. Measurement results of the antenna and the QWP show ≤ -10-dB reflection from 59 to 63 GHz (6.6%), ≤ 3-dB axial ratio from 59.5 to 61.5 GHz (3.3%), and an overall efficiency ≥ 77% from 59.5 to 61.5 GHz. The unit cell operating as a HWP is demonstrated in full-wave simulations for polarization rotation of the LP antenna, and for changing the sense of rotation of a right-hand CP antenna into left-hand circular polarization.

Substrate Integrated Waveguide-Based Dual-Polarized Self-Diplexing Antenna Array

Substrate Integrated Waveguide (SIW) cavity backed self-diplexing slot antenna array is proposed with dual-polarized capability. The antenna array is composed of four linearly placed full-duplex elements operating at 3.5 and 4 GHz independently. The antennas are designed inside a Half Mode SIW (HMSIW) cavity, and two capacitive slots adjust the resonant frequencies. Furthermore, two 1 by 4 power dividers all including 50-ohm transmission lines are designed to feed the radiators, thus resulting in a single layer antenna array integrated with feeding networks. Upon evaluating the simulated and measured results, the minimum reflection coefficients of -25 dB were observed at both operating frequencies. In addition, the data showed that the suggested structure brings about a high isolation level of more than 23 dB between two bands. It is also worth expressing that maximum gains of 10 and 11.5 dBi are obtained at 3.5 and 4 GHz, respectively. And, the radiation efficiencies are 0.78 and 0.9 for the low and high frequency bands.