Quadruple-ridged Waveguide Research Articles

Millimeter-Wave Dual-Polarized Metal Transmitarray Antenna With Wide Gain Bandwidth

By utilizing the quadruple-ridged waveguide (QRW), a high-gain dual-polarized all-metallic transmitarray (TA) antenna with wide gain bandwidth is proposed. The QRW has a fixed height with four identical ridges symmetrically located inside a square waveguide. The phase compensation is obtained by simultaneously controlling the length of the four ridges. The fully symmetrical structure of the QRW enables the proposed TA to achieve dual-polarization and two-dimensional (2-D) beam scanning. The proposed TA antenna with an aperture of 112 × 112 mm is designed and fabricated by utilizing 3-D metallic printed technology. The measured broadside gain at 30 GHz for the two orthogonal polarizations is 28.2 dBi and 28.1 dBi, corresponding to an aperture efficiency of 41.9% and 40.9%, respectively. The measured 1 and 3 dB broadside gain bandwidth is 27.3% and 34.8%, respectively. The 2-D beam scanning range at 30 GHz for the dual polarized radiation covers ±18°, with a maximum scan loss of 2.3 and 3.2 dB, respectively.

A Novel Compact Oversized Rectangular Waveguide Transition Based on Quadruple-Ridged Waveguide for Millimeter Wave Applications

In this paper, a broadband and compact oversized rectangular waveguide transition is proposed. Employing novel quadruple-ridged waveguide technology, two quadruple-ridged waveguides achieve an extreme compactness interconnection from a standard rectangular waveguide to an oversized rectangular waveguide. This design can be used as an alternative way to create a new oversized rectangular waveguide transition. The length of the transition is only 0.3λ, where λ is the TE10 mode wavelength at the center frequency. For verification purpose, a back-to-back transition was designed, fabricated, and measured. Measured results show that the return loss is greater than 20 dB and the insertion loss is less than 0.2 dB in the operating frequency band. Therefore, we can infer that the return loss and insertion loss of single transition are around 25 dB and 0.1 dB, respectively.

Contra-Directional Ridge Waveguide Couplers: Design and Applications

This article presents novel wideband contra-directional couplers based on single conductor ridge waveguide, and their applications. The couplers exhibit wide bandwidths and tight coupling while occupying very small volume due to the compactness of ridge waveguides. The methodology to design the couplers is presented. It is inspired by the even and odd modes used to design TEM coupled lines couplers but implemented with TE modes in this novel approach. The design starts with designing the coupling section in a quadruple-ridge waveguide that supports two independent even and odd TE modes. Proper choice of the cross section allows the designer to achieve the required impedance levels for the required coupling values. An S-band proof of concept prototype of a single coupler was synthesized, fabricated, and tested, demonstrating excellent measured results without any tuning. The couplers can be exploited in versatile applications, such as power sampling, beamforming, or high-power combiners. As an additional proof of concept design, a C-band three-way combiner was also designed and tested, showing the potential of the novel coupler for different applications.

A Ka-Band Circularly Polarized Substrate Integrated Cavity-Backed Antenna Array

A high-gain 4 × 4 substrate integrated waveguide (SIW) circularly polarized (CP) antenna array at a Ka-band with a quadruple-ridge waveguide polarizer is proposed in this letter. The antenna array consists of 16 cavity-backed slot antenna elements, quadruple ridge waveguide polarizers, and SIW T-type power dividers. Dominant resonant mode TE110 is excited in the cavity-backed slot antenna element. The measured impedance bandwidth ( S 11 < –10 dB) is from 35.3 to 35.55 GHz, and 3 dB axial-ratio bandwidth is from 35.24 to 35.57 GHz. In addition, the maximum measured gain of 18.14 dBi at the boresight is experimentally obtained at 35.42 GHz. The antenna prototype was fabricated by a multilayer printed circuit board technology. To the best of our knowledge, the quadruple-ridge waveguide is used as polarizer to produce CP signals for the first time. Compared with an aperture antenna with a conventional rectangle or a circular waveguide polarizer, this work has high aperture radiation efficiency as well as compact size. This design idea may open a new way for development of millimeter-wave high-efficiency arrays.

A compact high-efficiency power divider/combiner based on quadruple-ridged waveguide

A compact high-efficiency power divider/combiner based on quadruple-ridged waveguide

Dual-mode quadruple ridge waveguide feed for broadband satellite communications

A novel and compact dual-channel multimode waveguide system is described, which permits two distinct frequency channels, such as C-band and Ku-band, to be propagated simultaneously. The system is also dual-moded at both the lower and the upper frequencies, thus enabling polarisation switching between orthogonal linear signals or between left and right hand circularly polarised transmissions. The development is primarily motivated by the desire to provide extended range and global coverage, for a maritime satellite communications system, employing a single antenna platform.

QUAD RIDGED HORN ANTENNA FOR UWB APPLICATIONS

This paper describes a novel design of a dual-polarized ultra wideband horn antenna. Based on a VSWR ≤ 2.6, the bandwidth of the designed UWB horn antenna is from 8–18 GHz, most suitable for radar systems. A new coaxial line to quadruple-ridged waveguide transition and a new technique for tapering the flared section of the horn is introduced to improve the return loss and matching of the impedance, respectively. Results of simulation for VSWR, isolation, gain and radiation pattern of designed horn antenna are presented and discussed.

A NEW 2-18 GHZ QUAD-RIDGED HORN ANTENNA

A novel design of a dual-polarized broadband 2–18 GHz horn antenna with VSWR≤ 2.2 is presented. The designed horn antenna is most suitable as a feed element in reflectors of the radar systems and EMC applications. A coaxial line to quadruple-ridged waveguide transition with a new conical cavity back and a technique for tapering the flared section of the horn is introduced to improve the return loss and matching of the impedance, respectively. In order to overcome the deterioration of the broadside radiation pattern at higher frequencies, common to broad band ridged horn antennas, a new modified horn antenna with arc shaped aperture is introduced. Results of simulation obtained via two different software packages, HFSS and CST, for VSWR, isolation, radiation patterns, and gain of the designed quad ridged horn antenna as well as the modified horn antenna are presented and discussed.

Mode-matching analysis of quadruple-ridged square waveguides

The mode-matching method (MMM) is applied to analyze the propagation characteristics of quadruple-ridged square waveguides. Numerical results for the eigenvalues and characteristic impedance are presented and compared with available data in the literature. Good agreement is observed. Design examples are presented for the quadruple-ridged square waveguides operating at 2–18 GHz and 18–40 GHz, respectively. These two examples will be used in the design of dual-polarized broad-band horn antennas. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 190–194, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21120

A new dual-polarized broadband horn antenna

This letter describes a new design of dual-polarized broadband horn antennas. The bandwidth of the designed horn antenna is from 2 to 26.5 GHz. A novel coaxial line to quadruple-ridged waveguide transition is introduced to improve the return loss performance of the horn antenna. Measured results for VSWR, isolation, gain, and radiation pattern of the designed horn antenna are presented.

Vector finite element calculations of Faraday rotation in quadruple ridge waveguides with gyromagnetic tiles

The finite element method has by now been employed to characterize longitudinally magnetized circular, elliptical, and quadruple ridge gyromagnetic waveguides. Special cases have included ferrite rods on the axis of circular, triple, and quadruple ridge waveguides. The purpose of this paper is to employ this technique to investigate Faraday rotation in quadruple ridge waveguide with ferrite tiles on each open face. The topology in question has application in the design of high power variable power dividers in satellite work. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11, 148–155, 2001

Mode-matching analysis of circular-ridged waveguide discontinuities

This paper describes a mode-matching algorithm for S-parameter computation of circular-ridged waveguide (CRW) discontinuities. The ridges are shaped like the cross section of a cone (pie-shaped) with a geometry that can he described in cylindrical coordinates. This idea avoids the use of a mixed-coordinate system in the analysis of the electromagnetic fields in the ridged sections, which can, therefore, be expressed in terms of modal functions. The resulting algorithm is fast and accurate and has been utilized to design and optimize a five-section double-ridge filter and a quadruple-ridge waveguide transformer. The measured response of the filter is in good agreement with the calculated data.

Analysis and design of quadruple-ridged waveguides

In a previous paper, a unified approach has been proposed for the analysis and design of single- and double-ridged waveguides by a magnetic field integral equation (MFIE) formulation (see ibid., vol. 41, no. 11, p. 1965-71, Nov. 1993). This paper presents a continuing work with emphasis on the design of quadruple-ridged waveguides. The characteristics of square, circular and diagonal quadruple-ridged waveguides, including cutoff frequencies, attenuation, impedance and modal field distributions, are for the first time systematically analysed and reported. Distinct to being in a single- or double-ridged waveguide, the fundamental-mode in a quadruple-ridged waveguide has a cutoff frequency very close to that of the second-lowest mode, thus the natural single mode bandwidth is very small. However, when the second-lowest mode is effectively suppressed or not excited, a very wide bandwidth (6:1) can be achieved. This unique property, plus the capabilities of dual-polarization, high power, and low impedance, makes the quadruple-ridged waveguides well-suited to many antenna and microwave applications. >

Cutoff wavenumbers of ridged circular waveguides via Ritz-Galerkin approach

The cutoff wavenumbers of the TE11 and TE31 modes in double and quadruple-ridged circular waveguides are calculated by the Ritz-Galerkin method. The approach used and the computed data for the quadruple-ridged case are published for the first time.