Slotted Waveguide Antenna Research Articles

Correction: A novel design of non-bending narrow wall slotted waveguide array antenna for X-band wireless network applications

Correction: A novel design of non-bending narrow wall slotted waveguide array antenna for X-band wireless network applications

A novel design of non-bending narrow wall slotted waveguide array antenna for X-band wireless network applications

A novel design of non-bending narrow wall slotted waveguide array antenna for X-band wireless network applications

A Circularly Polarized Non-Resonant Slotted Waveguide Antenna Array for Wide-Angle Scanning.

A compact circularly polarized non-resonant slotted waveguide antenna array is proposed with the aim of achieving wide-angle scanning, circular polarization, and low side-lobe levels. The designed antenna demonstrates a scanning range of +11° to +13° in the frequency domain and a beam scanning range of -45° to +45° in the phase domain. This design exhibits significant advantages for low-cost two-dimensional electronic scanning circularly polarized arrays. It employs a compact element that reduces the aperture area by 50% compared to traditional circular polarization cavities. Additionally, the staggered array method is employed to achieve an element spacing of 0.57λ within the azimuth plane. Isolation gaps were introduced into the array to enhance the circular polarization performance of non-resonant arrays. The Taylor synthesis method was employed to reduce the side-lobe levels. A prototype was designed, fabricated, and measured. The results indicate superior radiation efficiency, favorable VSWR levels, and an axis ratio maintenance below 3 dB across the scanning range. The proposed antenna and methodology effectively broaden the beam scanning angle of circularly polarized slotted waveguide array antennas.

Design of the Monopulse Feeding Network for a Slotted Waveguide Array on an Annular Disk

Design of a monopulse feeding network including a compact power distribution network and a monopulse comparator for a dual polarization slotted waveguide array fabricated on an annular disk is presented in this paper. As the slotted waveguide array is arranged on an annular disk, the feeding network is more complicated than that of a regular array such as a rectangular array. The design details of some key waveguide components, such as the compact assembly of H-plane T-junctions and E-plane elbows used to connect power distribution networks and radiation waveguides, are provided. Quasiplanar magic tees are designed and used to construct the compact sum and difference comparator. The antenna system contains two comparators, which are used to generate sum and difference beams for horizontal polarization and vertical polarization, respectively. Finally, the monopulse slotted waveguide array antenna is divided into two modules, a comparator module and an antenna module (including power distribution network), and fabricated with the layered processing and bonding process. The comparator module is measured using a network analyzer to verify its amplitude-frequency characteristics and phase-frequency characteristics. Screwing the comparator module and the antenna module together, a monopulse slotted waveguide array antenna is obtained, and the sum beam and difference beam characteristics of the antenna are measured in a microwave chamber and presented.

Planar slotted waveguide antenna array for monopulse radar

In monopulse radar, along with mirror and lens antennas, slotted waveguide antenna arrays (SWA) are often used, especially in those cases when it is required to have a flat non-protruding shape and compact dimensions. The design and manufacturing of such antennas have specialties associated with the use of non-standard feeding systems of radiating waveguides, which are considered in this paper as the example of creation of a flat SWA intended for use in a monopulse search and tracking radar. The aim of the article is calculating and modeling a slotted waveguide antenna array based on a hollow metal waveguide with a given level of side lobes and main lobe width of the radiation pattern. The developed SWA contains a radiating and feeding part. The radiating part, with 24 linear resonant waveguide-slot antennas with longitudinal slots on the wide wall of the waveguide, is divided into two subarrays to realize the monopulse mode. Each subarray is fed from the feeding waveguide through slanted slots cut in the wide wall of the waveguide. The antenna design calculation has been carried out in the MathCad, and the modeling has been performed in CAD Ansys HFSS. The energy method has been used to calculate the coordinates of the longitudinal slots on the wide wall of the radiating waveguide as well as the inclined slots on the wide wall of the feeding one. The calculated radiation patterns of the developed antenna array in the E- and H-planes in sum and difference modes have been shown. The paper outlines the methodology for designing a monopulse antenna system using a SWA. The system forms a beam directed perpendicular to the antenna plane. During the design process, the slotted waveguide antenna array based on a hollow waveguide has been modeled and researched to obtain the required characteristics specified in the technical requirements. The proposed approach can be applied to practical antenna design for monopulse radars.

Efficiency enhancement of a circularly polarised slotted waveguide antenna array for Sub-THz applications

Efficiency enhancement of a circularly polarised slotted waveguide antenna array for Sub-THz applications

Generation of OAM beams with quasi omnidirectional pattern using simple slotted waveguide array

Theory and design aspects of the Slotted Waveguide Antenna (SWA) array for the simultaneous generation of Orbital Angular Momentum (OAM) modes are proposed in this paper. The proposed method is a novel approach to OAM generation that uses a simple feeding scheme and has better performance, especially in terms of mode purity. Due to its all-metallic structure, the high-power OAM beams with first-order modes (+1&-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ +1 \\, \\& \\,-1$$\\end{document}) can be generated simultaneously along the propagation axis but in opposite directions, which improves the coverage and makes the proposed SWA be used in applications like radar target detection by mounting it on a mechanically rotating platform. The proposed theory is verified by the electromagnetic (EM) simulations, followed by the experimental verification done on the laboratory prototype. The near-field characteristics of the proposed antenna confirm the generation of first-order OAM beams with high mode purity. The far-field characteristics show the high gain and quasi-omnidirectional radiation pattern. Transmission of high-power OAM beams with good far-field characteristics makes the proposed antenna mitigate the issues of long-range OAM communication to a certain extent. However, the proposed antenna can be served well in strategic applications where the mostly high-power microwave is involved.

Research into the Impact of Phase Shifter Failures on the Characteristics of Slotted Waveguide Array Antenna

Introduction. Currently, the impact of phase shifter (PS) failures on the characteristics of phased antenna arrays, slotted waveguide array antenna (SWAA) in particular, represents a significant problem. A review of publications shows that insufficient attention has been paid to PS failures.Aim. To investigate the characteristics of a SWAA in the event of PS failures, when their phase takes a value equal to zero instead of the required value.Materials and methods. The methods of statistical modeling methods were used to study the impact of failures on SWA characteristics. Calculations were carried using the Mathcad 15 software package.Results. An algorithm for statistical modeling of the impact of PS failures on SWAA characteristics is proposed. A relationship that connects the radiation pattern with the volume of the statistical sample and the number of failed PSs is given. The malfunctions of emitters from 5 to 35 out of 50 elements were studied. Changes in the following characteristics were obtained: standard deviation – from 0.064 to 0.18, radiation pattern width – from 8 to 18 %, the level of side lobes – from 13 to 59 %, radiation power – from 0.9 to 0.3.Conclusion. The results obtained can be used in radio-electronic systems with antenna arrays at the stage of their development. Future work will address PS failures with phases being established randomly and with random values, as well as the case of PS failures where power does not pass into the emitter. Another important direction concerns compensation of distortions resulting from failures of antenna elements.

Model of slot antenna for MPECVD of carbon nanostructure

A model of a slotted waveguide antenna for microwave plasma enhanced chemical vapor deposition (MPECVD) of carbon nanostructures at low pressure is developed. The performance of two slot applicator for the production of dense plasma in the working gas (argon) at a frequency of 2.45 GHz is investigated by EM field simulator. Results show that dimensions of the symmetrical slots (length l ≤ λg/2, width of d = 6-10 mm) and optimized angle (φ=32° with respect to the waveguide central line) have a strong influence on the impedance matching of the waveguide to the dielectric window and plasma column (1.5 < SWR < 2.5), and on the radiation efficiency. The dielectric plate and plasma column density were taken into account in the model in the optimisation of the dimensions of the slots. The mode structure of standing surface waves in the plasma column is investigated at three values of plasma density and results for the radial (n=1) and azimuthal wave numbers (m=3, 4, 5) are in agreement with experimental results.

A Method for Low Sidelobe Substrate-Integrated Waveguide Slot Antenna Design Applied for Millimeter-Wave Radars

With the development of millimeter-wave radar systems, substrate-integrated waveguide (SIW) slot antennas have been widely used. This paper presents a computational approach for calculating the equivalent normalized admittance of slot in low sidelobe SIW longitudinal slot antennas. In contrast to the existing methods, this method takes into account the impact of the N-slots coupling on the admittance. Through this method, fitting functions for resonant length and conductance are obtained, which describe the relationship between the resonant length, resonant conductance, and offset of slots. Moreover, based on the two fitting functions, a low sidelobe SIW longitudinal slot linear antenna is designed for millimeter-wave radar applications at 77 GHz. This antenna consists of a transition from the standard WR-12 waveguide to the SIW and a set of radiating slots. The simulation results indicate an impedance bandwidth of 4.8% and a gain of 13.2 dBi. The sidelobe level in the H-plane is below −28 dB, which meets the desired specifications and confirms the accuracy of the presented method.

Enabling Wide Bandwidth in Substrate-Integrated Waveguide Slot Antennas by Using Low-Index Metamaterials

Enabling Wide Bandwidth in Substrate-Integrated Waveguide Slot Antennas by Using Low-Index Metamaterials

High gain narrow wall standing wave slotted waveguide antenna with flanges

ABSTRACT In this study, narrow (edge) wall standing wave slotted waveguide antenna design is proposed. This antenna operates at 2.812 GHz in S frequency band. Also, the design equations and slot characterization method are given in this study. This antenna is designed with two flanges to shape the elevation pattern and to increase the antenna gain. This antenna provides low cross polarization without using any polarizer or any other structure. The designed antenna is suitable for high gain and high-power applications. The performance of the proposed design is examined with simulations and verified with measurements.

A Low RCS Waveguide Slot Antenna array with Metamaterial Absorber

We propose a novel design to reduce the radar cross section (RCS) of ridged waveguide slot antenna array with metamaterial absorber (MMA). The MMA consists of metallic pattern and solid metal on sides of a dielectric slab, of which the absorbing characteristics and mechanism are analyzed. The PEC ground plane of a ridged waveguide slot antenna array is covered by MMA. Both the simulated and measured results show that compared with the waveguide slot antenna array with a PEC ground plane, the RCS of proposed antenna array are reduced dramatically without degradation of antenna performance. Combining with the bandpass frequency selective surfaces technology, the guideline illustrated by the proposed examples will serve as a good candidate for the future design of low RCS antenna.

Ultra-low SLL slotted waveguide antenna array using Chebyshev aperture distribution function for MM-wave tracking radar applications

A non-uniform aperture distribution slotted waveguide antenna is presented. The slotted waveguide antenna array is chosen for its ease for aperture distribution control and the flexibility of gain adjustment. Multiple aperture distribution functions, including uniform, binominal, Chebyshev, and Blackman, have been extensively investigated to achieve the best possible side lobe suppression. These distribution functions have been converted to slot displacement from the center line of the antenna. Number of slots in the proposed array is chosen to be eight to satisfy the required gain for mm-wave radar tracking application. The proposed antenna is simulated and optimized using the full wave simulator package (CSTMWS). Rounded edge slots are adapted instead of the sharp ones, as they are more applicable for the CNC fabrication process. An eight-slot waveguide antenna is fabricated and gold-plated, considering the Chebyshev distribution approach. The proposed design achieves very stable radiation characteristics and performance over the operating bandwidth, which extends from 33.6 GHz up to 35.9 GHz. At 35 GHz, the total realized gain of the overall antenna is found to be 13.4 dBi, with an overall radiation efficiency of 95.21 %. An obvious low SLL of −30 dB is obtained at the frequency of 35 GHz. The low side lobe level parameter is very crucial for radar applications as it enhances the overall target SNR and reduces false target observations. The pre-stated antenna characteristics make it a good candidate for mm-wave radar applications and point-to-point communications (P2P).

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.

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.

Design and Realization of Wearable Textile Slotted Waveguide Antennas.

The design of wearable antennas presents a challenge from multiple perspectives, as they must meet technical requirements and satisfy safety standards while also being suitable for integration into clothing and aesthetically pleasing. In recent years, the development of conductive fabrics has, in many ways, allowed for significant progress in the manufacturing of wearable antennas, and in previous work, we developed textile slotted waveguide antennas using conductive textiles and traditional sewing processes. However, various aspects of the design and realization of such antennas remain challenging. In particular, this work investigates the issue of using foam-based molds, which enables the realization of thin, flexible, wearable antennas, as well as the issue of antenna feed, specifically the transition from a classic coaxial transmission line to a waveguide. The design of the transition was focused on simplicity and robustness, due to which we limited the number of degrees of freedom in the design process in order to achieve a structure suitable for mounting on textile waveguide antennas. In addition, the antenna design procedure and the body-channel model were considered in order to optimize the performance of the antennas and the wireless body-centric system itself. Several prototypes of different kinds were developed in the 5.8 GHz ISM band, confirming the feasibility of the proposed concepts through experimental results.

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%.

Performance Analysis of Slotted Waveguide Antenna for High Power Microwave Applications

Performance Analysis of Slotted Waveguide Antenna for High Power Microwave Applications

Half mode rectangular SIW slotted antenna for multiband operations using ANN optimization

AbstractA multiband half‐mode substrate integrated waveguide (HMSIW) slotted antenna is developed for ISM/WiMAX/WLAN applications. HMSIW technique has been utilized to acquire antenna compactness. Two inverted L‐shaped slots of half wavelength are embedded onto a HMSIW rectangular cavity for attaining a hybrid mode (i.e., Half‐mode of Half‐mode of ), which induces a lower resonance at 2.4 GHz. An inverted L‐shaped slot is influenced to radiate hybrid mode at 2.4 GHz, while the innermost inverted L‐shaped slot radiates modified mode at 3.30 GHz. A multiband is obtained by amalgamation of hybrid mode (at 2.4 GHz), modified mode (at 3.30 GHz) and modified mode (at 5.38 GHz). The radiating modes are elucidated by using mode theory methodology for ascertaining the resonance characteristics of the prototype antenna. The antenna parameters have been optimized by artificial neural network technique using MATLAB. The antenna geometry possesses a shrinkage size of 30 × 16 × 1.6 mm3, which has been designed on FR‐4 substrate. To vindicate the simulated consequence, the fabricated prototype has been tested. It contributes the fractional bandwidth of 6.4% (2.09−2.23 GHz) in the hybrid mode at 2.18 GHz, 9.03% (2.89−3.17 GHz) in the half cavity mode at 3.10 GHz and 9.96% (5.11−5.65 GHz) in the half cavity mode at 5.42 GHz, respectively, which is beneficial for ISM, WiMAX and WLAN band wireless applications.