Nader Behdad
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View article: Low-probability of Intercept/Detect (LPI/LPD) Secure Communications Using Antenna Arrays Employing Rapid Sidelobe Time Modulation
Low-probability of Intercept/Detect (LPI/LPD) Secure Communications Using Antenna Arrays Employing Rapid Sidelobe Time Modulation Open
We present an electronically-reconfigurable antenna array offering low probability of intercept/detect (LPI/LPD) and secure communications capabilities simultaneously at the physical layer. This antenna array is designed to provide rapidly…
View article: Class-E, active electrically small antenna with enhanced bandwidth-efficiency product and high radiated power at the high-frequency (HF) band
Class-E, active electrically small antenna with enhanced bandwidth-efficiency product and high radiated power at the high-frequency (HF) band Open
Antennas operating at the high-frequency (HF) band (3–30 MHz) are frequently electrically small due to the large wavelength of electromagnetic waves (10–100 m). However, the bandwidth-efficiency products of passively matched electrically s…
View article: Class-E, Active Electrically-Small Antenna for High-Power Wideband Transmission at the High-Frequency (HF) Band
Class-E, Active Electrically-Small Antenna for High-Power Wideband Transmission at the High-Frequency (HF) Band Open
Antennas operating at the high-frequency (HF) band (3-30 MHz) are frequently electrically small due to the large wavelength of electromagnetic waves (10-100 m). However, the bandwidth-efficiency products of passively matched electrically s…
View article: Sensitivity analysis of multipactor susceptibility zone to variations in secondary electron yield values
Sensitivity analysis of multipactor susceptibility zone to variations in secondary electron yield values Open
We present a sensitivity analysis of the multipactor susceptibility zones to variations in the secondary electron yield (SEY) of materials, specifically focusing on the first and second unity crossover points of SEYs. In conducting this re…
View article: Electromagnetic design of the transition section between modules of a wakefield accelerator
Electromagnetic design of the transition section between modules of a wakefield accelerator Open
The electromagnetic design of a transition section consisting of couplers for extracting the 180-GHz TM01 accelerating mode and 190-GHz HE11 dipole mode of a cylindrical corrugated waveguide used as a collinear wakefield accelerator is pre…
View article: Synthesis of Symmetric, Two-Element Biomimetic Antenna Arrays Using Singular Value Decomposition
Synthesis of Symmetric, Two-Element Biomimetic Antenna Arrays Using Singular Value Decomposition Open
We present a method for determining the four-port S-matrix of the external coupling network (ECN) for symmetric, two-element biomimetic antenna arrays (BMAAs) by employing singular value decomposition (SVD). The presented approach greatly …
View article: Design of a cylindrical corrugated waveguide for a collinear wakefield accelerator
Design of a cylindrical corrugated waveguide for a collinear wakefield accelerator Open
We present the design of a cylindrical corrugated waveguide for use in the A-STAR accelerator under development at Argonne National Laboratory. A-STAR is a high gradient, high bunch repetition rate collinear wakefield accelerator that uses…
View article: Review: Metaheuristic Optimization Algorithms
Review: Metaheuristic Optimization Algorithms Open
Artificial neural networks are used in a wide range of machine techniques that deal with it.Hundreds of well-known optimization algorithms are now easy to use, and essential scientific code libraries offer dozens of technologies.Given the …
View article: A Dual-Band Patch Antenna Employing a Folded Probe Feed for Nonlinear Radar Applications
A Dual-Band Patch Antenna Employing a Folded Probe Feed for Nonlinear Radar Applications Open
In this work, a set of custom folded-probe-fed patch (FPFP) antennas are designed to improve the performance of a nonlinear radar (NLR) system. To improve system performance, the custom antennas are designed to have high gain, relatively n…
View article: A Dual-Band Patch Antenna Employing a Folded Probe Feed for Nonlinear Radar Applications
A Dual-Band Patch Antenna Employing a Folded Probe Feed for Nonlinear Radar Applications Open
In this work, a set of custom folded-probe-fed patch (FPFP) antennas are designed to improve the performance of a nonlinear radar (NLR) system. To improve system performance, the custom antennas are designed to have high gain, relatively n…
View article: Fabrication and testing of corrugated waveguides for a collinear wakefield accelerator
Fabrication and testing of corrugated waveguides for a collinear wakefield accelerator Open
Significant progress has been made at Argonne National Laboratory in the development of a compact wakefield accelerator based on a cylindrical corrugated waveguide with a 2-mm ID and fine corrugations on the wall. The fabrication process o…
View article: Mechanically Reconfigurable, Beam-Scanning Reflectarray and Transmitarray Antennas: A Review
Mechanically Reconfigurable, Beam-Scanning Reflectarray and Transmitarray Antennas: A Review Open
We review mechanically reconfigurable reflectarray (RA) and transmitarray (TA) antennas. We categorize the proposed approaches into three major groups followed by a hybrid category that is made up of a combination of the three major approa…
View article: Feasibility Study of Microsecond Pulsed Microwave Ablation Using a Minimally Invasive Antenna
Feasibility Study of Microsecond Pulsed Microwave Ablation Using a Minimally Invasive Antenna Open
In this study we established the feasibility of producing localized ablation\nzones using microsecond pulsed microwave ablation (MWA) as an alternative to\nconventional continuous wave (CW) MWA. We verified that a thin floating-sleeve\ndip…
View article: Metamaterial-Inspired Vacuum Electron Devices and Accelerators
Metamaterial-Inspired Vacuum Electron Devices and Accelerators Open
Metamaterials (MTMs) are structured materials with subwavelength features that can be engineered to have some unique properties not found in nature, such as negative refractive index, reversed Doppler effect, and reversed Cherenkov radiati…
View article: Performance-Enhancement of Platform-Based, HF Direction-Finding Systems Using Dynamic Mode Selection
Performance-Enhancement of Platform-Based, HF Direction-Finding Systems Using Dynamic Mode Selection Open
We present a method to enhance the accuracy of platform-based, high-frequency (HF) direction-finding (DF) systems using dynamic mode selection. To improve bandwidth and efficiency, the metallic platform supporting the DF array is used as t…
View article: A Pilot Study of the Impact of Microwave Ablation on the Dielectric Properties of Breast Tissue
A Pilot Study of the Impact of Microwave Ablation on the Dielectric Properties of Breast Tissue Open
Percutaneous microwave ablation (MWA) is a promising technology for patients with breast cancer, as it may help treat individuals who have less aggressive cancers or do not respond to targeted therapies in the neoadjuvant or pre-surgical s…
View article: X‐band, mechanically‐beam‐steerable lens antenna exploiting the Risley prism concept
X‐band, mechanically‐beam‐steerable lens antenna exploiting the Risley prism concept Open
This study presents a beam‐steerable antenna system that uses two mechanically‐rotatable, phase‐shifting surfaces (PSSs) functioning like a pair of Risley prisms for beam scanning operation at X‐band. One of the PSSs also acts as a lens, p…
View article: Rapid development of application-specific flexible MRI receive coils
Rapid development of application-specific flexible MRI receive coils Open
Over the last 30 years, there have been dramatic changes in phased array coil technology leading to increasing channel density and parallel imaging functionality. Current receiver array coils are rigid and often mismatched to patient’s siz…
View article: Wide Dynamic Range, Angle-Sensing, Long-Wave Infrared Detector Using Nano-Antenna Arrays
Wide Dynamic Range, Angle-Sensing, Long-Wave Infrared Detector Using Nano-Antenna Arrays Open
We present a new technique for designing angle-sensing, long-wave infrared (LWIR) detectors. Angle detection in the proposed detector is achieved by measuring the ratio of the absorbed power in two closely-spaced, directive infrared antenn…
View article: Wideband, Beam-Steerable Reflectarrays Based on Minimum-Switch Topology, Polarization-Rotating Unit Cells
Wideband, Beam-Steerable Reflectarrays Based on Minimum-Switch Topology, Polarization-Rotating Unit Cells Open
We describe the results of a wideband, reconfigurable reflectarray concept based on polarization-rotating unit cells (PRUCs) with a minimum-switch topology design. To enhance the simplicity and decrease the cost, the approach focuses exclu…
View article: Metamaterial-Inspired Vacuum Electron Devices and Accelerators
Metamaterial-Inspired Vacuum Electron Devices and Accelerators Open
Metamaterials (MTMs) are structured materials with subwavelength features that can be engineered to have some unique properties not found in nature, such as negative refractive index, reversed Doppler effect, and reversed Cherenkov radiati…
View article: A mechanically based magneto-inductive transmitter with electrically modulated reluctance
A mechanically based magneto-inductive transmitter with electrically modulated reluctance Open
Magneto-inductive (MI) communication is a viable technology for wireless communications in underwater and underground environments. In this paper, a new design for an MI transmitter is presented. Unlike conventional MI transmitters that ut…
View article: A New Reconfigurable Antenna MIMO Architecture for mmWave Communication
A New Reconfigurable Antenna MIMO Architecture for mmWave Communication Open
The large spectrum available in the millimeter-Wave (mmWave) band has emerged as a promising solution for meeting the huge capacity requirements of the 5th generation (5G) wireless networks. However, to fully harness the potential of mmWav…
View article: Dual‐band platform‐mounted HF/VHF antenna design using the characteristic mode theory
Dual‐band platform‐mounted HF/VHF antenna design using the characteristic mode theory Open
The design of a dual‐band antenna mounted on a military platform is presented. The antenna operates in both high‐frequency (HF) and very‐high‐frequency (VHF) bands and consists of two half‐loops mounted on the platform. When the two half‐l…
View article: Reconfigurable Antennas in mmWave MIMO Systems
Reconfigurable Antennas in mmWave MIMO Systems Open
The key obstacle to achieving the full potential of the millimeter wave (mmWave) band has been the poor propagation characteristics of wireless signals in this band. One approach to overcome this issue is to use antennas that can support h…
View article: Characterizations of biodegradable epoxy-coated cellulose nanofibrils (CNF) thin film for flexible microwave applications
Characterizations of biodegradable epoxy-coated cellulose nanofibrils (CNF) thin film for flexible microwave applications Open
Wood pulp cellulose nanofibrils (CNF) thin film is a novel recyclable and biodegradable material. We investigated the microwave dielectric properties of the epoxy coated-CNF thin film for potential broad applications in flexible high speed…