Calculation of a Shielded Transmission Line, Containing Circular Cylindrical Conductors and Coplanar Waveguides on the Shield

Author(s):  
V.V. Tyurnev
2019 ◽  
Vol 17 ◽  
pp. 51-57
Author(s):  
Gerald Gold ◽  
Konstantin Lomakin ◽  
Klaus Helmreich ◽  
Uwe Arz

Abstract. An existing analytical transmission line model to describe propagation properties of coplanar waveguides including dispersion and radiation effects was extended to take into account surface roughness of conductor traces. The influence of parasitics is successively included in the simulation and compared to measurements. The device under test (DUT) was fabricated on an Al2O3 wafer. A metal and ceramic chuck was utilized during measurements up to 120 GHz. The extended model is then capable of precisely predicting propagation properties in a wide frequency range and can now be used for calibration purposes like the development of uncertainty budgets.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Karlo Costa ◽  
Victor Dmitriev ◽  
Janilson Souza ◽  
Gustavo Silvano

We analyze impedance matching and excitation properties of a plasmonic optical nanocircuit composed by a receiving and an emitting dipole connected by a two-wire optical transmission line. The circuit is fed by a circular Gaussian beam focused on the receiving dipole. The numerical analysis is performed by linear method of moments with a given surface impedance of gold cylindrical conductors. With this model, we analyze the variation of standing-wave response along the circuit in function of some geometrical parameters. We present some conclusions concerning impedance matching between the transmission line and the emitting dipole and coupling between the receiving dipole and the incident Gaussian beam.


2020 ◽  
Author(s):  
Panagiotis Theofanopoulos ◽  
Georgios Trichopoulos

We present an analysis of graphene loaded transmission line switches. Namely, we propose equivalent circuit models for graphene loaded coplanar waveguides and striplines and examine the switching performance under certain design parameters. As such, the models account for the distributed effects of electrically-large shunt switches in coplanar waveguides and we use the Babinet’s principle to derive the respective models for the coplanar stripline transmission lines. Using these models, we identify the optimum design of graphene switches based on transmission line characteristic impedance, scaling factor, graphene shape, and topology (series or shunt). We vary these parameters and obtain the insertion loss and ON/OFF ratio. Τhe extracted results can act as the design roadmap toward an optimum switch topology and emphasize the limitations with respect to fabrication challenges, parasitic effects, and radiation losses. In our models, we use measured graphene values (sheet impedance) instead of theoretical equations, to obtain the actual switching performance. Finally, the proposed equivalent models are crucial for this in-depth study; since, we simulated more than 2,000,000 configurations, a computationally challenging task with the use of full-wave solvers


PIERS Online ◽  
2007 ◽  
Vol 3 (7) ◽  
pp. 1102-1106 ◽  
Author(s):  
Jingjing Zhang ◽  
Thomas Y Hsiang

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