Comparison of full wave approaches for determination of microstrip conductor losses for MMIC applications

1990 ◽  
Vol 26 (25) ◽  
pp. 2076 ◽  
Author(s):  
E. Paleczny ◽  
D. Kinowski ◽  
J.F. Legier ◽  
P. Pribetich ◽  
P. Kennis
Keyword(s):  
Full Wave ◽  
Microstrip Conductor

scholarly journals Dielectric-induced surface wave radiation loss

2020 ◽  
Vol 476 (2236) ◽  
pp. 20190859
Author(s):  
Tobias Schaich ◽  
Anas Al Rawi ◽  
Trevor Morsman ◽  
Mike Payne
Keyword(s):  
Experimental Data ◽  
Surface Wave ◽  
Wave Mode ◽  
Wave Radiation ◽  
Mode Matching ◽  
Full Wave ◽  
Matching Technique ◽  
Surface Waveguide ◽  
Conducting Sheet

We investigate a model which shows how the introduction of a perturbing dielectric close to an electromagnetic surface wave leads to radiation away from the surface through the dielectric. This resembles a surface waveguide passing through a wall or being deployed underground. Our theory, which is based on the mode-matching technique, allows quantitative determination of losses from a bound surface wave mode up to the point of its complete extinction. For a surface wave supported by a coated, conducting sheet the attenuation due to the perturbing dielectric is calculated for a number of frequencies, permittivities of the perturbation and separations between the sheet and the perturbing dielectric. The accuracy of our results is verified by simulation of the system with a full-wave numerical solution. Finally, we report experimental data of perturbed surface waves on a cable, which are in qualitative agreement with our model.

scholarly journals Determination of Complex Conductivity of Thin Strips with a Transmission Method

Electronics ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 21 ◽  
Author(s):  
Morteza Shahpari
Keyword(s):  
Method Of Moments ◽  
Material Properties ◽  
Reflection And Transmission Coefficients ◽  
Complex Conductivity ◽  
Transmission Method ◽  
Reflection And Transmission ◽  
Wave Modelling ◽  
Transmission Coefficients ◽  
Full Wave

Induced modes due to discontinuities inside the waveguide are dependent on the shape and material properties of the discontinuity. Reflection and transmission coefficients provide useful information about material properties of discontinuities inside the waveguide. A novel non-resonant procedure to measure the complex conductivity of narrow strips is proposed in this paper. The sample is placed inside a rectangular waveguide which is excited by its fundamental mode. Reflection and transmission coefficients are calculated by the assistance of the Green’s functions and enforcing the boundary conditions. We show that resistivity only impacts one of the terms in the reflection coefficient. The competency of the method is demonstrated with a comparison of theoretic results and full wave modelling of method of moments and finite element methods.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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