Matched absorbing medium techniques for full-wave tlm simulation of microwave and millimeter-wave components

1998 ◽  
Vol 53 (3-4) ◽  
pp. 115-129
Author(s):  
Sandrick Le Maguer ◽  
Nestor Peña ◽  
Michel Ney
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tammy Chang ◽  
Saptarshi Mukherjee ◽  
Nicholas N. Watkins ◽  
David M. Stobbe ◽  
Owen Mays ◽  
...  

AbstractThis article presents a millimeter-wave diagnostic for the in-situ monitoring of liquid metal jetting additive manufacturing systems. The diagnostic leverages a T-junction waveguide device to monitor impedance changes due to jetted metal droplets in real time. An analytical formulation for the time-domain T-junction operation is presented and supported with a quasi-static full-wave electromagnetic simulation model. The approach is evaluated experimentally with metallic spheres of known diameters ranging from 0.79 to 3.18 mm. It is then demonstrated in a custom drop-on-demand liquid metal jetting system where effective droplet diameters ranging from 0.8 to 1.6 mm are detected. Experimental results demonstrate that this approach can provide information about droplet size, timing, and motion by monitoring a single parameter, the reflection coefficient amplitude at the input port. These results show the promise of the impedance diagnostic as a reliable in-situ characterization method for metal droplets in an advanced manufacturing system.


2011 ◽  
Vol 130-134 ◽  
pp. 1990-1993 ◽  
Author(s):  
Kuang Da Wang ◽  
Wei Hong ◽  
Ke Wu

In this paper, a broadband and simple vertical transition between substrate integrated waveguide and standard air-filled rectangular waveguide is design and experimentally verified. From full-wave simulation of the structure, a relative bandwidth of 19.5% in W-band with return loss better than 20dB is reached. Then, five copies of back-to-back connected transitions are fabricated on RT/Duroid 5880 substrate. The experimental results show that the transition pairs have an average of 15% relative bandwidth with return loss better than 12dB and insert loss lower than 1.2dB. To explain the differences between simulated and tested results, an error analysis is presented.


2015 ◽  
Vol 738-739 ◽  
pp. 103-106
Author(s):  
Yong Fang ◽  
Bao Qing Zeng ◽  
Wen Tao Zhang ◽  
Pu Wang

This paper presents millimeter wave characterization and models of various wire bond transitions between chip’s ground-signal-ground pad (GSG) and microstrip (MS), include single-wire-nomatch MS-GSG transition, double-wire-nomatch MS-GSG, single-wire-match MS-GSG transition, and double-wire-match MS-GSG transition. It also presents the 3D full-wave electromagnetic simulation. Analysis results show that the double-wire-match MS-GSG transition’s characteristic is better than other three transitions in the whole W band. The accurate extracted parameter values are used for the lumped equivalent circuit model, whose simulation results are good with the full wave simulation results. The error between lumped equivalent circuit and full-wave models is of the order of ±0.2dB for S11 and S21 in the frequency range 75 - 105GHz. The proposed lumped equivalent circuit is suitable to be implemented in commercial microwave CAD tools for the electromagnetic sensor designing.


Author(s):  
Andrey V. Mozharovskiy ◽  
Oleg V. Soykin ◽  
Aleksey A. Artemenko ◽  
Roman O. Maslennikov ◽  
Irina B. Vendik

Introduction. Increased data rate in modern communication systems can be achieved by raising the operational frequency to millimeter wave range where wide transmission bands are available. In millimeter wave communication systems, the passive components of the antenna feeding system, which are based on hollow metal waveguides, and active elements of the radiofrequency circuit, which have an interface constructed on planar printed circuit boards (PCB) are interconnected using waveguide-to-microstrip transition.Aim. To design and investigate a high-performance wideband and low loss waveguide-to-microstrip transition dedicated to the 60 GHz frequency range applications that can provide effective transmission of signals between the active components of the radiofrequency circuit and the passive components of the antenna feeding systemMaterials and methods. Full-wave electromagnetic simulations in the CST Microwave Studio software were used to estimate the impact of the substrate material and metal foil on the characteristics of printed structures and to calculate the waveguide-to-microstrip transition characteristics. The results were confirmed via experimental investigation of fabricated wideband transition samples using a vector network analyzer Results. The probe-type transition consist of a PCB fixed between a standard WR-15 waveguide and a back-short with a simple structure and the same cross-section. The proposed transition also includes two through-holes on the PCB in the center of the transition area on either side of the probe. A significant part of the lossy PCB dielectric is removed from that area, thus providing wideband and low-loss performance of the transition without any additional matching elements. The design of the transition was adapted for implementation on the PCBs made of two popular dielectric materials RO4350B and RT/Duroid 5880. The results of full-wave simulation and experimental investigation of the designed waveguide to microstrip transition are presented. The transmission bandwidth for reflection coefficient S11 < –10 dB is in excess of 50…70 GHz. The measured insertion loss for a single transition is 0.4 and 0.7 dB relatively for transitions based on RO4350B and RT/Duroid 5880.Conclusion. The proposed method of insertion loss reduction in the waveguide-to-microstrip transition provides effective operation due to reduction of the dielectric substrate portion in the transition region for various high-frequency PCB materials. The designed waveguide-to -microstrip transition can be considered as an effective solution for interconnection between the waveguide and microstrip elements of the various millimeter-wave devices dedicated for the 60 GHz frequency range applications.


1999 ◽  
Vol 54 (1-2) ◽  
pp. 30-42
Author(s):  
Samir Hammadi ◽  
Robert O Grondin ◽  
Samir El-Ghazaly ◽  
Stephen Goodnick

2021 ◽  
Author(s):  
Panagiotis Theofanopoulos

<div> <div> <div> <p>We present novel multi-bit unit-cell topologies for reconfigurable reflective surfaces –RRSs– (e.g., reflectarray antennas) with compact designs for millimeter-wave and terahertz (mmWave/THz) applications. Typically, mmWave/THz RRSs utilize one or multiple single-pole-single-throw (SPST) switches leading to single- or dual-bit modulated surfaces. These surfaces utilize the switches to manipulate the phase of the imping waves, beamforming the reflected waves to the desired direction. As such, RRSs are leveraged either for imaging or wireless communication applications, which typically require the formation of a single beam (no grating lobes) and high gains. The gain and quantization lobe levels of an RRS is strictly related to the number of phase bits utilized in the unit-cell. Explicitly, more phase bits lead to lower quantization errors and better maximum gain/aperture efficiency. However, increasing the number of phase bits requires more SPST switches integrated within the unit-cell, leading to complex designs with high RF losses. Herein, we present, for the first time, RRSs with up to 4 phase quantization bits (16 states) that maintain one switch-per-bit topology thus retaining a low-complexity design. The proposed RRSs is presented alongside a series of analytical and full-wave simulated results. </p> </div> </div> </div>


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