A focused‐beam methodology for measuring microwave backscatter

Schultz, John W.; Hopkins, Edward J.; Maloney, J.G.; Kuster, E.J.; Kesler, Morris P.

doi:10.1002/mop.20252

Cited by 11 publications

(17 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…assuming a symmetric S matrix and noting that μ ≈ μ 0 at all frequencies for the dielectric polymers in this study, so derivatives with respect to permeability vanish (Schultz 2012). Complex permittivity values obtained through 2-port S-parameter analysis using a transmission-based ( S 21 and S 12 ) algorithm, collected at 0 dBm (1 mW) output power and a frequency step size of Δf = 15 MHz, are presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…5 provides a measure of the fraction of beam power absorbed in the sample plates. The calibration does not fully address the potential sources of error in the permittivity measurements, which include phase error contributions from geometric uncertainty associated with the on-axis positioning and thickness of the sample plates, in addition to inherent uncertainties associated with the design of the focused beam system (Schultz 2012). Relative uncertainty of measured permittivity values for each sample type were calculated from 10 successive cycles of S-parameter and EM property extractions, with a full unmounting and remounting of the sample between each iteration.…”

Section: Resultsmentioning

confidence: 99%

“…noting that S is approximately symmetric for samples that are thin relative to microwave wavelength (Schultz 2012).…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Modeling a Lossy Dieletric Polymer-based Thermoacoustic High Power Microwave Directed Energy Exposure Detection System

2022

View full text Add to dashboard Cite

Presented are design considerations for a potential detection and measurement technique that could provide operational awareness of high power microwave (HPM) directed energy weapon exposure for force health protection applications, leveraging thermoacoustic (TA) wave generation as the field interaction mechanism. The HPM electromagnetic frequency (EMF) regime, used in applications in both the counter-materiel and non-lethal counter-personnel design space, presents real-time personnel exposure warning challenges due to the potentially wide variation in time and frequency domain characteristics of the incident beam. As with other EM-thermal interactions, the thermoacoustic wave effect provides the potential to determine EM energy and power deposition without the need to measure ambient field intensity values or overload-sensitive EMF survey equipment. Following measurement of relevant EM, thermal, and elastic material property values, a carbon-filled polytetrafluoroethylene (CF-PTFE) lossy dielectric medium subject to pulsed HPM was computationally modeled using the commercial finite element method multi-physics simulation software package COMSOL. The simulation was used to explore the impacts of various material properties on TA signal output as a function of simulated incident field power density, EM frequency, and pulse length, thereby informing the selection of system components for the further development of a full TA-based HPM detection chain.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Modeling a Lossy Dieletric Polymer-based Thermoacoustic High Power Microwave Directed Energy Exposure Detection System

2022

View full text Add to dashboard Cite

show abstract

“…Substrate geometry was coated with 50 nanometers thin gold (Au) layer by the process of optical lithography then a layer of 4 micrometers thin Ni was grown electrochemically and selective removal of gold form this layer takes place. In 2013 Trong N. Duong, Jayanti Venkatarama and Zhaolin Lu presented paper on Nanoplasmonics metamaterial "Enhancement of Ambient Energy Haresting Using a Metamaterial Lens" [14]. This paper is based on harvesting of Radio frequency energy by Metamaterial lens.…”

Section: Metamaterialsmentioning

confidence: 99%

Microstrip line Antenna Fabrication Material

Singh¹,

Bansal²,

Singhal³

2018

IJET

View full text Add to dashboard Cite

This paper presents an extensive survey of electromagnetic materials used for antenna fabrication, which find application in Civilian life as well as defense life. When a densely packed microwave integrated circuit is designed, it requires protection from higher power transient because of specific polarization and frequency response. To meet specification of such kind of microwave circuits it is desired to exploit properties of fabricating materials, which are not found in nature but can be prepared with specific proportion of chemical element combination. This study provides in-depth responses of materials toward electromagnetic wave's characteristics such as dielectric, flexible electronics, electrical and thermal properties, which have vast potential in communication engineering.

show abstract

“…The frequencies of the measurements are within the X-band range (from 8.2 to 12.4 GHz). The focused beam horn antenna was selected to minimize the effects of the experimental circumstances [ 17 ]. The 1-port calibration method for the focused beam environment with reflectors in several positions was proposed to improve the accuracy of the measured reflections.…”

Section: Introductionmentioning

confidence: 99%

Complex Permittivity Measurements of Steel Fiber-Reinforced Cementitious Composites Using a Free-Space Reflection Method with a Focused Beam Lens Horn Antenna

Cho¹,

Noh

et al. 2021

Sensors

View full text Add to dashboard Cite

To measure the electromagnetic properties of steel fiber-reinforced concrete (SFRC) in the X-band, 1-port measurements were performed using a lens horn antenna in a free-space measurement system. Free-space 1-port calibration with translations of the position of the reflector regarding the characteristics of the focused beam lens horn antenna was applied. The intrinsic impedance and complex permittivity of the SFRC were obtained from the measured reflection characteristics. The steel fiber content increased and the electromagnetic properties of the SFRC gradually changed from a dielectric to a conductor, even in very low frequencies compared to the plasma frequencies of general metal, which are optical frequencies. This is considered to be the plasmon effect of the metallic structure formed by the steel fiber. This result is applicable for analyses of the electromagnetic phenomenon of large structures with fiber content.

show abstract

A focused‐beam methodology for measuring microwave backscatter

Cited by 11 publications

References 4 publications

Modeling a Lossy Dieletric Polymer-based Thermoacoustic High Power Microwave Directed Energy Exposure Detection System

Modeling a Lossy Dieletric Polymer-based Thermoacoustic High Power Microwave Directed Energy Exposure Detection System

Microstrip line Antenna Fabrication Material

Complex Permittivity Measurements of Steel Fiber-Reinforced Cementitious Composites Using a Free-Space Reflection Method with a Focused Beam Lens Horn Antenna

Contact Info

Product

Resources

About