Characteristic impedance of coplanar waveguide

1985 ◽  
Vol 21 (13) ◽  
pp. 557 ◽  
Author(s):  
D. Bhattacharya
Keyword(s):  
Coplanar Waveguide ◽  
Characteristic Impedance

Effective resistivity extraction of low-loss silicon substrates at millimeter-wave frequencies

2020 ◽  
Vol 12 (7) ◽  
pp. 615-628
Author(s):  
Lucas Nyssens ◽  
Martin Rack ◽  
Jean-Pierre Raskin
Keyword(s):  
Millimeter Wave ◽  
Coplanar Waveguide ◽  
Characteristic Impedance ◽  
Wave Radiation ◽  
High Resistivity ◽  
Silicon Substrates ◽  
Dielectric Losses ◽  
Effective Resistivity ◽  
Novel Method ◽  
High Resistivity Silicon

AbstractThe effective resistivity (ρeff) is a figure of merit commonly used to assess the radio-frequency performance of a substrate from the measurements of coplanar waveguide lines. For highly resistive substrates, such as the trap-rich (TR) substrate, the extracted ρeff decreases by several orders of magnitude at millimeter-wave frequencies. The explanation for this decay is twofold. First, the imaginary part of the characteristic impedance ${\rm \lpar \Im }\lpar Z_c\rpar \rpar$ is not well extracted, which leads to an incorrect separation of the total losses among the metal and substrate losses. Second, the original expression of ρeff does not include dielectric losses, which might become non-negligible at millimeter-wave frequencies. This paper solves both issues by presenting a new procedure to extract ρeff and the dielectric losses simultaneously, and by introducing a novel method to correct ${\rm \Im }\lpar {Z_c} \rpar$. Furthermore, it is shown that this extraction method enables the correct extraction of substrate parameters up to 220 GHz of TR and high-resistivity silicon substrates. Finally, the origin of the large extracted value of dielectric loss is discussed in the potential presence of surface roughness and surface wave radiation. Both phenomena are discounted thanks to measurements of an additional reflective structure and a standard impedance substrate.

scholarly journals Microwave Properties of Coplanar Waveguide-Based PEDOT:PSS Conducting Polymer Line in Ethanol Gas Atmosphere

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1759 ◽  
Author(s):  
Hee-Jo Lee ◽  
Nathan Jeong ◽  
Hyang Hee Choi
Keyword(s):  
Conducting Polymer ◽  
Effective Conductivity ◽  
Coplanar Waveguide ◽  
Characteristic Impedance ◽  
Reference Sample ◽  
Test Sample ◽  
Microwave Properties ◽  
Significant Difference ◽  
Gas Atmosphere ◽  
Line Test

This study aims to investigate the microwave properties of coplanar waveguide (CPW)-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conducting polymer line in an ethanol gas atmosphere, with the frequency range of 0.5–2 GHz. For an ethanol-exposed PEDOT:PSS line (test sample), the transmission coefficient (S21) decreased immediately; moreover, the microwave effective conductivity (σm/w) decreased simultaneously, compared with the ethanol-free PEDOT:PSS line (reference sample). The immediate variations in ΔS21 ( = S21,ethanol − S21,free) and Δσm/w ( = σm/w,ethanol − σm/w,free) were approximately 10.2 dB and 2.7 × 104 S/m, respectively. Furthermore, in the analysis of the circuit model of the PEDOT:PSS line, the characteristic impedance and distributed elements, i.e., resistance (R) and inductance (L) per length, of the test sample increased, compared with the reference sample. However, upon stopping the exposure to ethanol gas, the microwave properties of the test sample instantaneously recovered to those of the reference sample. According to these critical observations, we could confirm that the coplanar waveguide with a PEDOT:PSS line shows a significant difference in the diverse microwave properties, through rapid response to the ethanol gas at room temperature.

Design and Characterization of Novel Millimeter-Wave MEMS CPW Transmission Lines

2011 ◽  
Vol 204-210 ◽  
pp. 577-582
Author(s):  
Jian Ming Huang ◽  
Y. L. Zhou ◽  
H. Guo
Keyword(s):  
Transmission Lines ◽  
Microelectromechanical Systems ◽  
Coplanar Waveguide ◽  
Characteristic Impedance ◽  
Effective Permittivity ◽  
Phase Shifters ◽  
Mapping Technique ◽  
60 Ghz ◽  
Loss Reduction ◽  
Propagation Properties

The design and development of novel microelectromechanical systems’ (MEMS) coplanar waveguide (CPW) transmission lines, using microshield and groove, are presented in the paper to operate between 5–60 GHz. The quasi-static capacitances of CPW are calculated using the conformal mapping technique to express the propagation properties, i.e., the characteristic impedance and effective permittivity. Simulation results have shown a considerable loss reduction to levels that compare favorably with the conventional CPW. These transmission lines can be widely used in the development of phase shifters, filters, and antennas, because of their advantages in loss reduction and improvement in the performance.

Liquid-Crystal-Based Floating-Electrode-Free Coplanar Waveguide Phase Shifter with an Additional Liquid-Crystal Layer for 28-GHz Applications

2021 ◽  
Author(s):  
Junseok Ma ◽  
Jin Young Choi ◽  
Seung-Won Oh ◽  
Wook-Sung Kim
Keyword(s):  
Liquid Crystal ◽  
Phase Shifter ◽  
Coplanar Waveguide ◽  
Characteristic Impedance ◽  
Thickness Variation ◽  
Driving Voltage ◽  
Electrode Thickness ◽  
Electric Flux ◽  
First Time ◽  
Floating Electrode

Abstract A liquid-crystal (LC)-based floating electrode-free (FE-free) coplanar waveguide (CPW) phase shifter with an additional LC layer is demonstrated for the first time. An LC layer is overlain on the electrodes of the original model; this change increases the amount of electric flux that the proposed structure can confine in the tunable region, and thereby greatly increases the figure-of-merit (FoM) while maintaining the benefits of the simple coplanar structure. We simulated the variations in the phase shifter’s FoM, characteristic impedance, and driving voltage while sweeping the additional LC layer thickness up to 300 μm with each electrode condition at 28 GHz. In the case of electrode thickness variation, the FoM increased as electrode thickness increased, regardless of the presence of the additional LC layer. However, in the case of the signal electrode width variation, we obtained an opposite FoM tendency depending on the presence of the additional LC layer. This work shows the possibility of an efficient LC-based FE-free CPW phase shifter design for a given LC layer and electrode conditions.

Integrated Microwave Noise Suppressor Fabricated on Magnetic/Dielectric Composite Ceramic Substrate

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000208-000215 ◽  
Author(s):  
Zheng Chen ◽  
Yanqiu Li ◽  
Liangliang Li
Keyword(s):  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Characteristic Impedance ◽  
Composite Ceramic ◽  
Oxide Ceramic ◽  
Magnetic Nanowires ◽  
Magnetic Nanowire ◽  
Aluminum Oxide Ceramic ◽  
Ferromagnetic Resonance Frequency ◽  
20 Nm

We fabricated coplanar waveguide noise suppressors on anodic aluminum oxide ceramic substrates filled with 20 nm Co ferromagnetic nanowires, and measured the microwave properties of the integrated noise suppressors from 10 MHz to 40 GHz. The working frequency of the device is 16–20 GHz and the transmission coefficient S21 of the device is about −5 dB. We analyzed the characteristic impedance matching for the magnetic nanowire-based noise suppressors and provided the theoretical equations to calculate the ferromagnetic resonance frequency of the magnetic nanowires for various cases.

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