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Full-Text Articles in Engineering
Novel Near-Field Microwave And Millimeter Wave Differential Probe Using A Dual-Modulated Single Aperture, Mohamed A. Abou-Khousa, R. Zoughi
Novel Near-Field Microwave And Millimeter Wave Differential Probe Using A Dual-Modulated Single Aperture, Mohamed A. Abou-Khousa, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
A novel differential probe design is introduced in this paper for near-field microwave and millimeter wave non-destructive testing (NDT) and imaging applications. In such applications, the variations in the distance between the probing antenna and the structure under inspection, i.e., standoff distance, can potentially mask the signal of interest, and hence, adversely impact the detection capability of the probe. Differential near-field probes and compensation methods were developed in the past to null out the standoff distance variation effect from the measured signal. The available methods, however, suffer from some limitations such as using two balanced apertures or offering limited range …
A Novel 24 Ghz One-Shot, Rapid And Portable Microwave Imaging System, Mohammad Tayeb Ahmad Ghasr, Mohamed A. Abou-Khousa, Sergey Kharkovsky, R. Zoughi, David Pommerenke
A Novel 24 Ghz One-Shot, Rapid And Portable Microwave Imaging System, Mohammad Tayeb Ahmad Ghasr, Mohamed A. Abou-Khousa, Sergey Kharkovsky, R. Zoughi, David Pommerenke
Electrical and Computer Engineering Faculty Research & Creative Works
Development of microwave and millimeter wave imaging systems has received significant attention in the past decade. Signals at these frequencies penetrate inside of dielectric materials and have relatively small wavelengths. Thus, imaging systems at these frequencies can produce images of the dielectric and geometrical distributions of objects. Although there are many different approaches for imaging at these frequencies, they each have their respective advantageous and limiting features (hardware, reconstruction algorithms). One method involves electronically scanning a given spatial domain while recording the coherent scattered field distribution from an object. Consequently, different reconstruction or imaging techniques may be used to produce …
Multimodal Solution For A Rectangular Waveguide Radiating Into A Multilayered Dielectric Structure And Its Application For Dielectric Property And Thickness Evaluation, Mohammad Tayeb Ahmad Ghasr, R. Zoughi
Multimodal Solution For A Rectangular Waveguide Radiating Into A Multilayered Dielectric Structure And Its Application For Dielectric Property And Thickness Evaluation, Mohammad Tayeb Ahmad Ghasr, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
Open-ended rectangular waveguides are widely used for microwave and millimeter wave nondestructive testing applications. Applications have included detecting disbonds and delaminations in multilayered composite structures, thickness evaluation of dielectric sheets and coatings on metal substrates, etc. When inspecting a complex multilayered composite structure, made of generally lossy dielectric layers with arbitrary thicknesses and backing, the dielectric properties of a particular layer within the structure is of particular interest, such being health monitoring of structures such as radomes. The same is also true where one may be interested in the thickness or more importantly thickness variation of a particular layer within …
Potential Application Of The Modulated Scatterer Technique To Multilayered Material Evaluation And Health Monitoring, Kristen M. Munoz, Amy K. Perrey, R. Zoughi
Potential Application Of The Modulated Scatterer Technique To Multilayered Material Evaluation And Health Monitoring, Kristen M. Munoz, Amy K. Perrey, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
Modulated scatterer technique (MST) is based on illuminating a small antenna, usually a dipole, loaded with a PIN diode, with an electromagnetic wave. The scattered (or reflected) wave from the probe may then be used to determine dielectric properties of the material in which the probe is located or embedded. The PIN diode is turned "on" and "off" which not only changes the impedance of the probe, but also modulates (with the same rate) the reflection from the probe. A major challenge associated with MST is detecting and distinguishing the desired probe response in the ever-present reflections from surrounding structures …