Quad-ridged Horn Research Articles

Optimizing dual-band antenna efficiency: Ridge width parametric study of quad ridge horn antennas

The purpose of this project was to develop a quad ridged horn antenna for a GSM and mid band 5G application, capable of dual frequency range operation at 1.8 GHz and 3.5 GHz. The antenna was constructed using 3D printing technology and Polylactic Acid (PLA), a thermoplastic polymer known for its high strength and compatibility with 3D printing processes. The impact of varying ridge width dimensions on the antenna's performance was evaluated using a range of parametric techniques. Ridge widths of 10 mm, 13.5 mm, and 17 mm were analysed to assess the effects of dimension alterations. Results demonstrated that the antenna is capable of dual band frequency operation with signal reflections of -16.89 dB and -28.60 dB at 1.8 GHz and 3.5 GHz, respectively. This research contributes to the development of efficient and cost-effective antennas for wireless communication applications in the GSM and mid band 5G spectrum.

Quadband Petal Reflector Antenna for Ground Communications: Combining four frequency bands into one innovative and reliable design

Future protected communications require soldiers on the ground to carry several antennas integrated with their manpacks to provide secure and reliable communications at a number of frequency bands. This article describes a novel quadband petal reflector antenna (QPRA) that combines four frequency bands into one using a quadruplexer. A dual-reflector antenna utilizing an axially displaced ellipsoid subreflector being fed with a quad-ridged horn provides communications at Ku-band transmit (Ku-Tx), Ku-band receive (Ku-Rx), K-band receive (K-Rx), and Ka-band transmit (Ka-Tx) frequencies simultaneously. The main reflector is made of six identical petals that can be quickly assembled and disassembled in the battlefield. The antenna is mounted on a lightweight gimbal to provide beam scanning over a hemispherical coverage. The antenna is mounted on a tripod structure for field operations and uses commercial off the shelf (COTS) components and 3D manufactured parts to minimize cost and mass. The novelty of the antenna presented in this article includes a wide bandwidth capability of 73%, the use of a petal reflector, a 3D manufactured quad-ridged horn, a high-performance quadruplexer, and the use of COTS gimbals for beam scanning. Antenna design, analyses, hardware, and test results are presented in this article. The measured results of the antenna agree well with the computed results validating the QPRA design.

Design of ultra-wide band dual-polarized quad ridged horn antenna for obstacle penetrating radar imaging applications

In this study, a high-gain and dual-polarized Quad Ridged Horn Antenna (QRHA) is proposed and designed to be used in Obstacle Penetrating Imaging Radar (OPIR) applications. The quad ridged design is developed and then optimized by using the antenna design simulator software; CST Microwave Studio. The antenna parameters including the center frequency, frequency bandwidth and the antenna radiation pattern beam width are considered based on the requirements of OPIR applications. The final design is obtained for the center frequency of 2.785 GHz with a -10 dB bandwidth of at least 2.5 GHz. The final designed QRHA is able to provide a gain of 12.4 dB with a beam width of 36ᵒ at the center frequency of 2.785 GHz.

Solving Sub-Wavelength Lattice Reduction in Full-Metal Front-Ends for Dual-Polarized Active Antennas

This article proposes an original structure of evanescent quadridge antenna (EQA) to conceive dual-polarized full-metal front-ends that can be used in active antennas (AAs) with wide field-of-view (FoV). An original design methodology is here proposed that allows to induce radiation from subwavelength squared apertures based on the use of evanescent and quadridge waveguides. The proposal is illustrated by means of a design with 4.5% bandwidth providing dual-circular polarization (CP) with good performance up to 50°-scanning even in the diagonal plane. For comparison purposes, a metallic benchmark is also proposed, which is based on the use of classical quadridge horns. Such comparative analysis allows to understand the superior performance of the proposed concept and its main advantage: it allows to avoid the excitation of the first high order mode in the squared quadridge aperture. The excitation of such spurious mode in the antenna is explained in terms of simple equivalent circuit models characterizing the aperture periodic discontinuity.

Coupling Reduction of Two Adjacent Quad-Ridge Horn Antennas at 20-40 GHz Frequency Range by Using of Wideband Electromagnetic Band Gap Structure

In this paper, the Electromagnetic Band-Gap (EBG) structures have been used to decrease the mutual coupling between two wideband quad-ridge horn antennas. The EBG structure is a small sheet with a length of 6 cm and a width of 10.6 cm, and it was placed vertically between the horn antennas, providing us with a very compact system. Full-wave CST simulations have been carried out to simulate the whole structure. A two-layer EBG structure has provided a 17 dB isolation over the 20-40 GHz frequency range. Moreover, to verify the proposed structure, EBG layers have been fabricated and measured. The S parameter and far-field measurements of the horn antennas were conducted to investigate the isolation and radiation patterns of the antennas. The measurement results were perfectly comparable with the simulations. Moreover, because of the standalone characteristic of the designed EBGs, this structure can be used as an add-on unit to decrease the E-plane mutual coupling of any two antennas.

Wideband Dual-Polarized 3D Printed Quad-Ridged Horn Antenna

This paper presents the development of a wideband dual-polarized 3D printed quad-ridged horn antenna (QRHA) that can be used for detecting and imaging applications. The QRHA consists of three main parts: the waveguide transducer, the horn, and the ridges. The waveguide transducer is modified into a square shape to obtain dual-polarization. Four variations of ridges were carried out to determine the ridge that best satisfies the required specifications, especially the bandwidth and sidelobe levels. Among the four ridge profiles, the quadratic model was used for the proposed QRHA as it generated the widest bandwidth and enhanced a lower operating frequency, which is beneficial for improving resolution and penetration depth. The double-ridged horn antenna (DRHA) was also investigated in order to make a comparison with QRHA’s performance. The characterization results show that when compared to DRHA, QRHA performs better in terms of bandwidth, beamwidth, gain, and side lobe suppression. Due to the benefits it provides, 3D printing based on polylactic acid (PLA) material was selected as the manufacturing process for the proposed QRHA. The fabricated QRHA had a weight that was three times lighter compared to conventional antennas. The measurement results indicate that the 3D printed QRHA has the wideband characteristics of a −10 dB working bandwidth of 7.9 GHz in frequency ranges of 3.5 GHz to 11.4 GHz. Isolation between the ridges below −20 dB was achieved for most frequency ranges. Co– and cross-polarizations were also performed to evaluate the dual-polarization of the proposed QRHA. The radiation patterns showed that the measurement results agree well with the simulations for low, middle, and high operating frequencies.

Balanced Feed Low Cross-Polarization Quad-Ridged Horn Antenna With Center Cross Fusiform Loaded

This communication presents a novel quad-ridged horn (QRH) antenna incorporating a balanced feed. A cross-shaped fusiform structure is mounted in the center of the QRH. The fusiform structure has the effect of suppressing the cross-polarization component by improving the conventional QRH TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> mode. The communication presents an equivalent circuit that has been derived for the proposed balanced feed network. Four SMA probes are symmetrically distributed around the horn wall and the inner conductors of the two probes facing each other are connected. The cross-polar level, within a 30° solid angle, is less than -23 dB from 2 to 6 GHz. The measured isolation between two orthogonal linearly polarized ports is higher than 42 dB and the return loss is lower than -15 dB over the entire working frequency band.

Design and analysis of quad ridged horn antenna for high gain application

This paper discusses the design consideration of a Quad Ridged horn Antenna (QRHA). The different ridge profiles that are inserted in the horn have different significant effect on the horn performance that are discussed in the paper. The paper is based on the QRHA that can be used as a Standard Gain Horn Antenna. The QRHA is simulated using HFSS software and the results obtained are mentioned.

Ultrawideband Flush-Mountable Dual-Polarized Vivaldi Antenna

A dual-polarized, flush-mounted, Vivaldi antenna directly integrated with all-metal cavity is introduced as an alternative to coax-fed quad-ridge (QR) horns. Eigen-mode analysis is used to demonstrate that the entire structure may resonate with degraded impact on its far-field when not properly integrated with the cavity. An approach based on shaping the side walls of the cavity is used to eliminate the occurrence of these resonances. The proposed dual-polarized resonant-free antenna has two orthogonal 2 × 1 arrays with two elements in the E-plane and one element in the H-plane and is fed using two 2-way power dividers that can be easily designed to maintain low amplitude and phase imbalances. The antenna is fabricated in a single piece and experimentally shows monotonic gain increase with low cross-polarization over 4:1 bandwidth. Symmetric far-field performance between orthogonal polarizations with gain better than 8 dBi and sidelobe levels lower than -20 dB from 2 to 8 GHz is demonstrated. VSWR <; 2, and port to port isolation greater than 35 dB is also measured over the same bandwidth.

On the curve and impedance-wall improvement of quad-ridged horn in the application of compact range simulation

The ridge curve profile and impedance wall configuration is of great importance for the wideband feed performance improvement. This paper addressed a new design of ridge curve and impedance wall structure to eliminate the negative effect caused by the side-lobe of the feed, especially in the lower frequency. Therefore, the mutual coupling between transmitter and receiver has been reduced so that the Quiet Zone performance is enhanced. The simulations results were demonstrated and corresponding conclusions were obtained.

Design of dual‐polarised (RHCP/LHCP) quad‐ridged horn antenna with wideband septum polariser waveguide feed

This study was conducted to design a wideband septum polariser as a feeder of the antenna to generate right-hand circular polarisation (RHCP) and left-hand circular polarisation (LHCP) concurrently. The proposed septum polariser overcomes the conventional bandwidth limit and covers 40% bandwidth from 8 to 12 GHz. Moreover, a quad-ridged horn is chosen as a radiator of the feeding network due to its waveguide structure, wide bandwidth , and dual polarisation. Therefore, the proposed structure consists of a quad-ridged horn fed by a square waveguide, a waveguide transition, and a wideband septum polariser. The final design has an axial ratio <;1.5 dB over the X-band. This configuration can be used as a feed for reflector antennas due to the wideband and dual polarisation characteristics. Furthermore, the structure is highly recommended for high-power applications because of its waveguide feature.

Isolation Improvement Techniques for Wideband Millimeter-Wave Repeaters

Two passive approaches for improving the isolation between flush-mounted transmitting (TX) and receiving (RX) antennas over 45–110 GHz are investigated. Both configurations exploit a reactive impedance surface (RIS) that suppresses TM polarized surface waves propagating on the ground plane between the TX and RX antennas. Quarter-wavelength corrugated one-dimensional (1-D) RIS is shown to improve isolation by ∼20 dB in an octave bandwidth (45–90 GHz), whereas concentric corrugations around the antennas improve isolation over the same bandwidth with better antenna radiation characteristics at the low end. On the other hand, an isolation improvement of ∼15 dB over the entire bandwidth is obtained with an array of grounded circular patches 2-D RIS. Computational studies are validated with measurements of quad-ridge horns with 3-D printed corrugations and printed circuit board 2-D RIS patches.

Monostatic Co-Polarized Full-Duplex Antenna With Left- or Right-Hand Circular Polarization

A monostatic dual-polarized simultaneous transmit and receive (STAR) antenna system with high isolation is introduced. A beamforming network (BFN) producing 0°, ±90°, ±180°, and ±270° phase progression is used to feed TX and RX ports of four dual-polarized antenna elements arranged in a sequential rotation array (SRA). Due to the phase progression and geometrical symmetry of SRA, the coupling from TX to RX ports is canceled at the RX port of the BFN; therefore, infinite system isolation is theoretically obtained. Full-wave simulations are used to verify the theory and study effects of element spacing and BFN imbalances. An additional cancelation layer is designed and used to compensate for the imbalances by the BFN and nearby scatterers. The proposed STAR antenna system is prototyped and tested in the 2.4–2.5 GHz industrial, scientific, and medical band where the measured isolation and return loss are above 47 and 22 dB, respectively. A dual circularly polarized antenna performance with realized gains above 7 dBic, broadside axial ratio <1.6 dB, and symmetric beams is demonstrated. An ability of the proposed monostatic STAR antenna system to achieve wideband operation is also demonstrated with a quad-ridge horn as an element.

Wideband Decoupling Techniques for Dual-Polarized Bi-Static Simultaneous Transmit and Receive Antenna Subsystem

A wideband, bistatic, and dual-polarized simultaneous transmit and receive antenna subsystem with isolation >60 dB over 6–19 GHz band is demonstrated. The proposed configuration employs two quad-ridge horns fed by a ridge waveguide ortho-mode transducer (OMT) as transmitting (TX) and receiving (RX) antennas. The OMT enables dual-polarized high-power operation for the TX antenna over the entire bandwidth. The TX/RX antennas are flush mounted in a flat ground plane and oriented in D-plane to achieve similar isolation for both polarizations. Different decoupling techniques for increasing isolation between TX/RX antennas are investigated. Specifically, a high capacitive reactance bed of nails is designed to suppress TM polarized surface waves on the metallic ground plane. Moreover, a wideband planar and low-profile high-impedance surface is developed and performance thereof is compared to that of the other considered surfaces. Effect of recessing the RX antenna in an absorber is also discussed. Computational and experimental studies are conducted to demonstrate and validate the performance of the proposed antenna subsystem. Good impedance match, excellent radiation characteristics, and high isolation are achieved.

45–110 GHz Quad-Ridge Horn With Stable Gain and Symmetric Beam

A quad-ridge horn antenna with stabilized gain and minimum difference between E- and H-plane half-power beamwidths (HPBWs) is demonstrated for operation over 45–110 GHz bandwidth. Multistep flaring and corrugations on a finite ground plane are applied to obtain stable radiation patterns with 16-dBi minimum gain over the entire range. The computational studies are validated through measurements of a 3-D printed prototype using the direct metal laser sintering (DMLS) process. Accurate fabrication with achieved surface roughness of $ of the fabricated antenna is verified with digital microscope. The obtained gain variation, VSWR, and HPBW variation with rotation and over 45–110 GHz bandwidth are below 1.7 dB, 1.7:1, and 9°, respectively. This work demonstrates that the DMLS is a viable fabrication process for wideband horn antennas at millimeter-wave frequencies.

Tx-Rx Lens-Based Satellite-on-the-Move Ka-Band Antenna

A simple low-cost mobile ground terminal antenna for Ka-band satellite communications is presented. The antenna is composed of a shaped dielectric lens which tilts and rotates in front of a feed to direct the beam. The wideband feed system is composed of a quad-ridged horn with a $45^{\circ}$ slant aperture and a coaxial-to-quad-ridged circular waveguide transition. The lens allows simple mechanical beam steering from 0 $^\circ $ to 65 $^\circ $ in relation to the zenith and 360 $^\circ $ in azimuth by rotating both the lens and the feed slanted aperture. Performance measurements of a manufactured prototype prove the beam tilting capabilities in elevation with a maximum gain of 22 dBi and scan loss below 3 dB at 20 GHz and 24 dBi gain with less than 4.5 dB scan loss at 30 GHz.

English

Antennas are one of the most important parts of a communication chain. They are used for both communication and calibration purposes. Antenna measurement techniques involving near-field probes have been a recently developing area. New developments in probe technologies have enabled near-field probes with much larger bandwidth. The objective of this Master's Thesis is to design, simulate and fabricate a dual polarized wideband inverted quad ridged shape horn antenna which can be used as measurement probe for near field measurements. Typical probes like Open Ended Waveguides, dipole antenna probes etc are bulky in mobile communication frequency bands. In addition they are narrow band probes. The inverted quad-ridged horn antenna probe not only provides measurement in the much wider range but also provides dual-polarization measurement thus enabling antenna developers to measure UWB, UHF, VHF antennas more precisely and at lower cost. The antenna is designed to meet the characteristics such as high gain, light weight, linearly polarized with suppressed side lobes for near-field measurement applications. The proposed antenna is simulated with commercially available packages such as Ansoft HFSS. The antenna gives a moderate gain over operating range while delivering a wide bandwidth.

An optimized quad-ridged horn antenna with pyramidal sidewalls

The wideband gain and voltage standing wave ratio (VSWR) performance of quad-ridged horn antennas in general are restricted due to the excitation of higher order modes in the coaxial to quad-ridged waveguide transition. This results in large gain variations vs. frequency and break-up of the radiation patterns at higher frequencies. In this paper, a quad-ridged horn antenna is presented with optimized radiation characteristics and VSWR performance. The performance of the antenna was optimized by separating the antenna into two subsections, viz. a coaxial to quad-ridged waveguide transition section and a flared quad-ridged horn section. The performance of each section was optimized individually using a numerical solver – CST Microwave Studio. Three possible configuration of the coaxial to quad-ridged waveguide transition section were considered and optimized. Four configurations for the flared quad-ridged horn section were also investigated. The best performing configuration from each one of the two sections were combined to yield the final design of the optimized quad-ridged horn antenna. The numerical performance of the quad-ridged horn antenna was validated through measurements, performed in a compact antenna test range. The optimized antenna has a 12.5:1 frequency bandwidth from 0.8 to 10 GHz. Over this frequency range, the antenna has a VSWR performance typically better than 2.5:1, stable boresight gain and radiation patterns for both ports with more than 30 dB isolation between the two ports.

Quad-Ridge Horn Antenna With Elliptically Shaped Sidewalls

We present a quad-ridge horn antenna as a feed for a reflector antenna for use in radio astronomy applications. The antenna uses elliptically shaped sidewalls to limit the variation of beamwidth over a wide frequency range and to obtain greater radiation pattern rotational symmetry. The antenna is dual-polarized and matched over more than a 4:1 bandwidth. A design procedure is presented and a prototype designed according to this procedure is shown. Measured and simulated results of the prototype agree with each other well. The antenna is analyzed with a prime focus reflector to determine the range of efficiencies that can be expected.

Spherical Horn Array for Wideband Propagation Measurements

A spherical array of horn antennas designed to obtain directional channel information and characteristics is introduced. A dual-polarized quad-ridged horn antenna with open flared boundaries and coaxial feeding for the frequency band 600 MHz–6 GHz is used as the element of the array. Matching properties and coupling between the elements are investigated via measurements and numerical simulations. Radiation patterns and sum beams of the array on selected frequencies throughout the band are also presented. Based on the obtained results it is concluded that the array is a good candidate for a wideband multipath propagation studies.