A. R Sebak

A. R Sebak
Concordia University Montreal · Department of Electrical and Computer Engineering

Doctor of Engineering

About

579
Publications
94,635
Reads
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6,555
Citations
Citations since 2016
178 Research Items
4481 Citations
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800

Publications

Publications (579)
Article
Full-text available
A compact ultra-wideband printed ridge gap waveguide directional couplers for millimeter-wave applications are presented in this paper. A multi-layer coupling technique between two resonant patches is adopted to achieve a wider operating bandwidth with better amplitude and phase balance compared to single-layer technology. For this purpose, a syste...
Article
This paper presents a unique design of a dual-polarized wideband passive beam-switching antenna at millimeter-wave bands for MIMO pattern diversity applications, which exhibits low correlation between the ports and a broad tilt bandwidth. A magneto-electric (ME) dipole fed by a printed ridge gap waveguide (PRGW) as a quasi TE source is considered a...
Article
A 2-D beam switching dipole antenna working at 60 GHz is proposed. To realize this, a folded electric-field coupled (ELC) resonator is designed to achieve a high-refractive-index medium in the band of 57–64 GHz. By integrating an array of ELC resonators in the off-center of a printed dipole antenna in the E- and H-planes forming high-refractive-ind...
Article
Full-text available
The millimeter-wave (mm-wave) band is expected to be the optimal solution for future wireless communication systems as it provides a wide bandwidth, which enhancing data transmission rate. Therefore, high-directive antennas, principal elements for mm-wave wireless communications, are used at the mm-wave band as they can overcome the negative effect...
Article
Full-text available
The manuscript presents the design and characterization of a wideband front-end receiver, based on hollow waveguide technology, for the wireless access point (WAP) applications. The Ka-band receiver is comprised of a low-loss beam-switching antenna network (BSAN) with two-dimensional (2D) scanning property. For demodulation, the receiver uses an ef...
Article
Full-text available
Printed ridge gap waveguide (PRGW) is considered among the state of art guiding technologies due to its low signal distortion and low loss at MillimeterWave (mmWave) spectrum, which motivates the research community to use this guiding structure as a host technology for various passive microwave and mmWave components. One of the most important passi...
Article
Full-text available
A two-dimensional (2D) periodic leaky-wave antenna (LWA) is proposed in this paper. Using dielectric-filled wedge-like waveguide as medium for wave propagation, the quasi-TEM wave inside the guide is leaked through periodic rings of narrow slots, resulting in high gain frequency-dependent beam. Due to the two-dimensional nature of the antenna, alon...
Article
Full-text available
This paper presents a new design for a wideband circularly polarized (CP) spiral antenna array fed by a differential aperture coupling. The differential excitation is realized by two vias located at the lateral sides of a transverse slot etched on the lower substrate. The proposed two-arm spiral antenna has a smaller size compared to conventional s...
Article
Full-text available
In this paper, a detailed analytical study of using an improved antenna probe for hyperthermia applications is presented. The proposed antenna exhibits a narrow beam width with more focused energy over the mid-point of the antenna probe. The antenna probe operates in the ISM band around 2.45 GHz. In order to verify the probe performance, extensive...
Article
Full-text available
In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive ele...
Article
A perfect magnetic conductor (PMC) packaging concept is utilized at 30 GHz, which suppresses the higher order cavity modes, improves insertion losses, and helps in developing packaged microstrip lines (PMSLs) and double-ridge gap waveguide (DRGW) transmission lines. The Quasi-TEM PMSLs are used to design quadratic hybrid, crossover, and phase shift...
Article
Full-text available
A millimeter‐wave radar based on active invers scattering approach for two dimensional screening of metallic and nonmetallic concealed targets is presented. The perceived challenges of detecting a nonmetallic target exhibiting poor dynamic range for measurement systems are analyzed and discussed by comparing the performance of three different anten...
Article
In this paper, we implement three types of data-driven algorithms for the inverse design of the polarization rotator (PR)unit-cell. Toward this end, a novel configuration pattern of PR unit-cell is proposed which is reshapable to different geometries with a large number of design variables and recasts as a regression problem. The state-of-the-art a...
Article
Full-text available
A wideband circularly polarized slot spiral antenna array excited by a printed gap waveguide (PGW) feeding network is presented in this paper. The equiangular slot spiral is etched on the top wall of the substrate integrated cavity (SIC) in which TE120 mode is excited. Due to excitation of this mode, electric field distribution in two halves of the...
Article
In this paper, broadband, low radar cross section (RCS) engineered surface with the ability of operating over a wide range of oblique incident angles is presented. Two types of artificial magnetic conductor (AMC) unit-cells with a 180°±37° reflection phase differences are developed. Perforated superstrate is loaded on the top of conventional metall...
Chapter
In this chapter, an ultra-wideband printed ridge gap T-junction is presented. A T-junction is an essential component in feeding antenna arrays and power division networks. The printed ridge gap technology is selected as it has a low profile, supports quasi-TEM mode, and has very low losses. The design depends on using one quarter wave transformer a...
Article
In this article, the design of full-band rectangular waveguide pressure windows for high power applications is presented. The proposed design features a compact size, low loss, and a simplified fabrication process. A short impedance step is deployed to achieve a deep matching level over the full band of the standard waveguide. An approximate circui...
Article
Full-text available
An output arm is the first subsystem in the microwave components chain connected immediately after the power amplifier. These arms are responsible for transferring the signal from the output port of the power amplifier to the standard line of the system. The second objective is to obtain directive samples for both forward and backward signals. The...
Conference Paper
A broadband planar circularly polarized antenna based on the differential excitation of an asymmetrical spiral antenna is presented in this paper. The proposed feeding method of the spiral antenna is an appropriate alternative to the complex balun circuits used in conventional spiral antennas. The simulation results show that the CP antenna covers...
Article
Full-text available
In this paper, experimental evaluations over the frequency range of a 57–64 GHz for an improved millimeter wave (MMW) imaging/detection system have been conducted. The main objective behind this work is to examine the performance of a high gain and low profile multi sine corrugated AFTSA antenna sensor in the detection of metallic, non-metallic wea...
Article
Full-text available
In this paper, a wideband 3 dB hybrid 180° rat-race coupler is introduced in the printed ridge gap waveguide technology. It has simultaneous wide matching and isolation bandwidth with low output amplitude imbalance. It operates in the millimeter wave band from 25.8 to 34.2 GHz (27.96%) with 15 dB return loss and isolation, and ±0.5 dB output amplit...
Article
Full-text available
This paper proposes a compact, semi-circular shaped multiple input multiple output (MIMO) antenna design with high isolation and enhanced bandwidth for ultrawide band (UWB) applications. A decoupling stub is used for high isolation reaching up to −55 dB over the entire bandwidth. The proposed antenna is used for UWB as well as super wide band (SWB)...
Article
Full-text available
An ultra-compact triple-band bandpass filter based on dual-mode quarter-wave resonator for GSM, GPS, and WiFi applications is presented in this study. The filter consists of three quarter-wave resonators assisting in controlling each passband independently. The first operating frequency band is obtained by the direct-feed resonator which acts as a...
Conference Paper
The 6G race has already begun, and many countries and giant corporations started directing significant efforts and funds towards the development of the future technology. The 6G standard is expected to migrate to higher bands of frequencies to support wider bandwidth. Through this wide bandwidth, it will be feasible to serve the expected massive nu...
Conference Paper
The near-to-launch 5G standard for wireless communications did not seal the ultimate use the mm-wave bands. As a result, the future 6G standard is expected to proceed in more efficient utilization of these bands. One of the most critical elements in the RF link is the amplifier, especially when the attenuation of the channel is relatively high whic...
Article
Full-text available
A wideband differential fed patch antenna with high cross-polarization discrimination is proposed at mm-wave range. For the purpose of increasing antenna bandwidth, capacitive coupling technique is used. Also, the differential feeding is utilized to ensure broadside radiation and low cross-polarization. The designed antenna has an ultra-wide bandwi...
Article
A novel high-efficiency 8-beams dual-polarized array antenna using an 8×8 beamforming network is studied and developed at 60-GHz. Two 4×4 Butler matrices are employed as base beamformers, and two 4×8 pattern control networks are utilized for increasing the number of the radiating elements and suppressing sidelobes in the proposed dual left/right-ha...
Article
Full-text available
A new design of the double dielectric resonator antenna (DRA) fed by a printed ridge gap waveguide for beam‐switching applications based on frequency selective surfaces (FSSs) is presented here. The dual‐sided printed FSS element works in its reflection mode and comprises a slotted square C‐shaped patch on the top layer and a square strip on the ba...
Article
Full-text available
!In this paper, a magneto-electric (ME) dipole antenna excited by two slots through a printed ridge gap waveguide (PRGW) is presented. This antenna, which operates in the Ka-band, is considered as a dual complementary source (DCS), and exhibits a higher gain and a wider impedance bandwidth, compared to conventional ME dipoles. The proposed antenna...
Article
A wideband printed ridge gap waveguide 4×4 Butler matrix at 30 GHz is presented. The printed ridge gap technology is used as it has very low losses and supports the propagation of quasi-TEM mode. Each component of the Butler matrix has been designed and analyzed where a superior performance is achieved in terms of bandwidth and size. The designed c...
Article
In this paper, a dual-polarized magneto-electric (ME) dipole antenna is implemented in the printed ridge gap waveguide (PRGW) technology. The antenna is composed of a cross-shaped ME-dipole backed by an artificial magnetic conductor (AMC) sidewall cavity. This cavity is fed by two orthogonal PRGWs implemented in two separate layers to achieve a dua...
Article
This paper presents four different approaches utilized in beam tilting that are based on the phase gradient (phase shifting) surfaces. Each approach is individually analyzed and then compared to other techniques. Beam tilting is obtained through various techniques by transforming the phase distribution of Fabry-Perot cavity antenna (FPCA) in the ne...
Article
Full-text available
A novel experimental evaluation of millimeter-wave imaging / detection system based on time domain reflectometry (TDR) is presented. The proposed 60 GHz-band system is characterized by high precision, lightweight, low profile, and utilization of low cost scanning probes. As a scanning sensor, multi sin-corrugation antipodal tapered slot antenna (MC...
Article
Full-text available
A packaged microstrip line feed network on a single-substrate surface is presented in the ka-band for a 4×4 dual-polarized array with a capability to be expanded to higher-order ${\rm{2^{N}\times2^{M}}}$ where N and M are integer numbers larger than 1. A dual-polarized aperture-coupled magneto-electric dipole antenna is designed as a single eleme...
Article
A substrate integrated waveguide (SIW)-fed bow-tie antenna that is loaded with meander-line H-shaped electric metamaterial resonators and double-sided split ring resonators (DSRRs) (magnetic metamaterial resonators) is proposed to realize a single high-gain antenna at 60 GHz. The antenna achieves a maximum gain of 13.8 dBi at 62 GHz from a single e...
Article
In this article, a $1 \times 4$ dual-polarized magnetoelectric (ME) dipole antenna array is proposed. The antenna is excited by a dual-polarized fork-shaped microstrip line based on printed ridge gap waveguide technology. To achieve additional gain, a dual-polarized split-ring resonator (SRR) is designed, which has a mu-near zero (MNZ) feature. T...
Article
A reconfigurable surface, for electromagnetic (EM) wave manipulation, utilizing frequency selective unit-cells integrated with PIN diodes are introduced. By digitally controlling the reconfigurable surface, several functionalities such as focusing, linear polarization conversion and scattering are obtained on the same surface. For the scattering pu...
Article
In this paper, a novel design of dielectric resonator antenna (DRA) with a reconfigurable radiation pattern capability is presented. Reconfigurability in the azimuth plane is achieved by symmetrically placing six electromagnetic bandgap (EBG) sectors around the DRA. Each sector is composed of twenty-six circular shaped mushroom-like EBG unit cell....
Article
This manuscript focuses on the design of a transparent circularly polarized (CP) antenna subarray integrating with CubeSat’s solar panels. The sub-array antenna employs two techniques including the Fabry_Perot cavity (FPC) and sequential rotation-feeding network. These techniques are used to generate CP along with a high level of directivity over a...
Article
Full-text available
In this paper, a systematic design methodology of a 0dB and a 3dB forward couplers based on the ridge gap waveguide (RGW) technology is presented. This methodology is based on exact theoretical formulations rather than any approximate or empirical equations. The procedure of the proposed design methodology is mainly to build a virtual equivalent wa...
Conference Paper
Full-text available
A 2×2 dual-polarized passive analog beamforming network is presented for millimeter-wave application in the range of 28-32 GHz. Two identical 2×2 networks, one for each polarization (H and V) are integrated on a single substrate layer. Highly isolated crossover is used to cross the RF signal for each polarization. To avoid spurious radiation, the m...
Article
Full-text available
The evolution of a wireless communication system to the fifth generation is accompanied by a huge improvement in the performance of the communication system through providing high data rate with a better coverage area. Hence, 5G technology requires access to millimetre wavebands where more spectra are available for high‐speed applications. This tec...
Article
The Ka band has found applications in satellite, and radar communications. It is also expected that this band will be utilized for 5G applications. This paper presents single- and double-beam microstrip reflectarrays with single layer and compact size for Ka band communications at 28 GHz. Three different unit cells are investigated in this paper. S...
Article
Advanced! electromagnetic (EM) surfaces, namely meta-surfaces, are designed for multifunctional purposes. A glass material with a chessboard configuration is exploited to realize non-absorbing coating for backscattering reduction. Simultaneously, a solar cell is implemented above the metallic target for light energy harvesting using the transparenc...
Article
Full-text available
The development of wireless and satellite communication has led to a demand for high performance microwaves and mm-wave components in terms of cost, losses, and fabrication complexity. Gap waveguide is one of the emerging technologies in 5G and mm-wave applications due to their low cost, low losses and high power handling capability. In this work,...
Article
In this article, a wideband metasurface for radar cross-section (RCS) reduction based on a polarization conversion is presented. The unit cell is composed of a two-layer metasurface based on frequency-selective surfaces (FSSs) backed by a thin-grounded dielectric substrate. The metasurface is able to rotate the polarization by 90° using special bin...
Article
In this paper, a differential feeding circular polarized antenna array implemented with printed ridge gap waveguide technology for millimeter wave applications is proposed. The differential feeding power divider is designed based on aperture coupling to achieve a stable 180o phase imbalance over 20% operating bandwidth at 30 GHz with sufficient mat...