Fork-Coupled Resonators for High Frequency Characterization of Dielectric Substrate Materials

Abstract—Efficient coupling of energy in and out of a resonator can significantly enhance its performance, particularly when used for dielectric characterization of materials. In this paper, a new microstrip resonator is introduced, which uses fork-shaped feed elements for improving the coupling efficiency. The proposed resonator is studied both experimentally and theoretically with field simulation software. An important advantage of the fork microstrip resonator is attributed to its single-layer geometry and easier manufacturing processes. This resonator is used to characterize three different dielectric materials. Comparison of measurement results from the fork resonator with those obtained with a stripline resonator suggests that the proposed resonator offers a superior performance

Fork-Coupled Resonators for High Frequency Characterization of Dielectric Substrate Materials

Abstract—Efficient coupling of energy in and out of a resonator can significantly enhance its performance, particularly when used for dielectric characterization of materials. In this paper, a new microstrip resonator is introduced, which uses fork-shaped feed elements for improving the coupling efficiency. The proposed resonator is studied both experimentally and theoretically with field simulation software. An important advantage of the fork microstrip resonator is attributed to its single-layer geometry and easier manufacturing processes. This resonator is used to characterize three different dielectric materials. Comparison of measurement results from the fork resonator with those obtained with a stripline resonator suggests that the proposed resonator offers a superior performance

Fork-Coupled Resonators for High-Frequency Characterization of Dielectric Substrate Materials

Efficient coupling of energy in and out of a resonator can significantly enhance its performance, particularly when used for dielectric characterization of materials. In this paper, a new microstrip resonator is introduced, which uses fork-shaped feed elements for improving the coupling efficiency. The proposed resonator is studied both experimentally and theoretically with field simulation software. An important advantage of the fork microstrip resonator is attributed to its single-layer geometry and easier manufacturing processes. This resonator is used to characterize three different dielectric materials. Comparison of measurement results from the fork resonator with those obtained with a stripline resonator suggests that the proposed resonator offers a superior performanc

Fork-Coupled Resonators for High-Frequency Characterization of Dielectric Substrate Materials

Efficient coupling of energy in and out of a resonator can significantly enhance its performance, particularly when used for dielectric characterization of materials. In this paper, a new microstrip resonator is introduced, which uses fork-shaped feed elements for improving the coupling efficiency. The proposed resonator is studied both experimentally and theoretically with field simulation software. An important advantage of the fork microstrip resonator is attributed to its single-layer geometry and easier manufacturing processes. This resonator is used to characterize three different dielectric materials. Comparison of measurement results from the fork resonator with those obtained with a stripline resonator suggests that the proposed resonator offers a superior performanc

UWB through-the-Wall Propagation

The propagation of ultrawideband (UWB) signals in indoor environments is an important issue with significant impacts on the future direction and scope of UWB technology. The propagation of UWB signals is governed, among other things, by the properties of materials in the propagation medium. The information on electromagnetic properties of construction materials in the UWB frequency range would provide valuable insights into the appreciation of the capabilities and limitations of UWB technology. Although electromagnetic properties of certain construction materials over relatively narrow bandwidths in GHz frequency ranges are available, ultrawideband characterisation of most typical construction materials for UWB communication purposes has not been reported. In narrowband wireless communications, only the magnitude of insertion loss has been the quantity of interest. But for UWB signals, in addition to the magnitude, the phase information is an equally important factor that needs to be accounted for. In fact, UWB signals not only suffer attenuation when propagating through walls, but also suffer distortion due to the dispersive properties of the walls. This research examines propagation through typical construction materials and their ultrawideband characterisation. Ten commonly used construction materials are chosen for this investigation. Results for the dielectric constant and loss tangent of the materials over the UWB frequency range are presented. Accuracy of the measured results is discussed and distortions of UWB signals due to the dispersive properties of wall materials are addressed

Path-loss and time dispersion parameters for indoor UWB propagation

The propagation of ultra wideband (UWB) signals in indoor environments is an important issue with significant impacts on the future direction and scope of the UWB technology and its applications. The objective of this work is to obtain a better assessment of the potentials of UWB indoor communications by characterizing the UWB indoor communication channels. Channel characterization refers to extracting the channel parameters from measured data. An indoor UWB measurement campaign is undertaken. Time-domain indoor propagation measurements using pulses with less than 100 ps width are carried out. Typical indoor scenarios, including line-of-sight (LOS), non-line-of-sight (NLOS), room-to-room, within-the-room, and hallways, are considered. Results for indoor propagation measurements are presented for local power delay profiles (local PDP) and small-scale averaged power delay profiles (SSA-PDP). Site-specific trends and general observations are discussed. The results for path-loss exponent and time dispersion parameters are presented

UWB through-the-Wall Propagation

The propagation of ultrawideband (UWB) signals in indoor environments is an important issue with significant impacts on the future direction and scope of UWB technology. The propagation of UWB signals is governed, among other things, by the properties of materials in the propagation medium. The information on electromagnetic properties of construction materials in the UWB frequency range would provide valuable insights into the appreciation of the capabilities and limitations of UWB technology. Although electromagnetic properties of certain construction materials over relatively narrow bandwidths in GHz frequency ranges are available, ultrawideband characterisation of most typical construction materials for UWB communication purposes has not been reported. In narrowband wireless communications, only the magnitude of insertion loss has been the quantity of interest. But for UWB signals, in addition to the magnitude, the phase information is an equally important factor that needs to be accounted for. In fact, UWB signals not only suffer attenuation when propagating through walls, but also suffer distortion due to the dispersive properties of the walls. This research examines propagation through typical construction materials and their ultrawideband characterisation. Ten commonly used construction materials are chosen for this investigation. Results for the dielectric constant and loss tangent of the materials over the UWB frequency range are presented. Accuracy of the measured results is discussed and distortions of UWB signals due to the dispersive properties of wall materials are addressed

Statistical results from the Virginia Tech propagation experiment using the Olympus 12, 20, and 30 GHz satellite beacons

Virginia Tech has performed a comprehensive propagation experiment using the Olympus satellite beacons at 12.5, 19.77, and 29.66 GHz (which we refer to as 12, 20, and 30 GHz). Four receive terminals were designed and constructed, one terminal at each frequency plus a portable one with 20 and 30 GHz receivers for microscale and scintillation studies. Total power radiometers were included in each terminal in order to set the clear air reference level for each beacon and also to predict path attenuation. More details on the equipment and the experiment design are found elsewhere. Statistical results for one year of data collection were analyzed. In addition, the following studies were performed: a microdiversity experiment in which two closely spaced 20 GHz receivers were used; a comparison of total power and Dicke switched radiometer measurements, frequency scaling of scintillations, and adaptive power control algorithm development. Statistical results are reported

Rigorous characterization of acoustic-optical interactions in silicon slot waveguides by full-vectorial finite element method

For the first time detailed interactions between optical and acoustic modes in a silicon slot waveguide are presented. A new computer code has been developed by using a full-vectorial formulation to study the acoustic modes in optical waveguides. The results have shown that the acoustic modes in an optical slot waveguide are not purely longitudinal or transverse but fully hybrid in nature. The model allows the effects of Stimulated Brillouin Scattering and the associated frequency shift due to the interaction of these hybrid acoustic modes with the fully hybrid optical mode also to be presented