Electromagnetic Waves and Transmission Lines for Wearable Communication Systems Designers

Author(s):  
Albert Sabban
2018 ◽  
Vol 64 ◽  
pp. 05004
Author(s):  
Ying Lu ◽  
Zhibin Zhao ◽  
Jian gong Zhang ◽  
Zheyuan Gan

The passive interference of transmission lines to nearby radio stations may affect the effective reception and transmission of radio station signals. Therefore, the accurate calculation of the electromagnetic scattering of transmission lines under the condition of external electromagnetic waves is the basis for determining the reasonable avoidance spacing of the two. For passive stations operating in short-wave frequencies, passive interference is mainly generated by the tower, and span is one of the most significant factors affecting passive interference. This paper uses the method of moments to carry out the passive interference calculations under normal circumstances, expounds the method of calculating the electromagnetic field of transmission line at the same time. And elaborates the method for calculating the electromagnetic field of the transmission line, obtains the space electric field intensity of the transmission line at the same working frequency and space location of the plane wave. Applying the approximate formula to calculate the formula for the span and critical distance between the observation point and the transmission line.


2018 ◽  
Vol 64 ◽  
pp. 05005
Author(s):  
Ying Lu ◽  
Zhibin Zhao ◽  
Jian gong Zhang ◽  
Zheyuan Gan

The passive interference of transmission lines to nearby radio stations may affect the effective reception and transmission of radio station signals. Therefore, the accurate calculation of the electromagnetic scattering of transmission lines under the condition of external electromagnetic waves is the basis for determining the reasonable avoidance spacing of the two. For passive stations operating in short-wave frequencies, passive interference is mainly generated by the tower. This paper uses the method of moments to perform passive interference calculations under normal circumstances, And elaborates the method for calculating the electromagnetic field of the transmission line, obtains the space electric field intensity of the transmission line at the same working frequency and space location of the plane wave. Uses the approximate formula to inductive the formula for calculating height of tower and the protective distance.


2020 ◽  
pp. 23-46
Author(s):  
Joshua Birndorf ◽  
Scott Ingram

Historic telegraph and telephone material culture are frequently encountered but seldom differentiated during archaeological site and survey work in Colorado. The poles, wires, and insulators that comprise these cultural resources are often recorded simply as transmission lines. The research reported here is the first archaeologically focused comparative study of telegraph and telephone material culture designed to help archaeologists differentiate between the two communication systems. Differentiating and documenting these systems fills gaps in an inadequate historical record of their spatial and temporal evolution and contributes to site and survey area interpretations. We find substantial material culture similarities due to shared hardware and the temporal overlap of the introduction of these systems to Colorado. We also identify several material attributes to help differentiate the systems. Accurately identifying cultural resources is a mainstay of archaeological work and we make progress by understanding the possibilities and challenges of differentiating these poorly documented resources.


2021 ◽  
Author(s):  
Carlos Molero ◽  
Ángel Palomares-Caballero ◽  
Antonio Alex-Amor ◽  
Ignacio Parellada-Serrano ◽  
Francisco Gamiz ◽  
...  

The upcoming high-speed wireless communication systems will be hosted by millimeter and sub-millimeter-wave frequency bands. At these frequencies, electromagnetic waves suffer from severe propagation losses and non-line-of-sight (NLOS) scenarios. A new wireless communication paradigm has arrived to resolve this situation through the use of reconfigurable intelligent surfaces (RIS). These metadevices are designed to reconfigure the wireless environment in a smart way. Traditional RIS designs based on the implementation of 2-D configurations have been considered up to now. However, 3-D structures enable an extra degree of freedom in the design that can be taken as an advantage for the development of improved RIS structures with advanced functionalities. This article proposes the implementation of a novel electronically-reconfigurable RIS based on the use of 3-D graphene meta-atoms. The reconfigurability lies on the graphene conductivity, easily tunable with a biasing voltage. Different conductivity values vary the meta-atom electromagnetic response, modifying the RIS functionality. A multi-objective optimization framework determines the optimal phase state of each meta-atom to accomplish the desired RIS performance. The operation of the RIS as an efficient beam steerer/splitter, absorber and polarization selector is validated with full-wave results.


Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1475 ◽  
Author(s):  
Vasa Radonić ◽  
Slobodan Birgermajer ◽  
Ivana Podunavac ◽  
Mila Djisalov ◽  
Ivana Gadjanski ◽  
...  

In this paper, we propose a novel metamaterial-based microfluidic sensor that permits the monitoring of properties of the fluid flowing in the microfluidic reservoir embedded between the composite left–right handed (CLRH) microstrip line and the ground plane. The sensor’s working principle is based on the phase shift measurement of the two signals, the referent one that is guided through conventional microstrip line and measurement signal guided through the CLRH line. At the operating frequency of 1.275 GHz, the CLRH line supports electromagnetic waves with group and phase velocities that are antiparallel, and therefore the phase “advance” occurs in the case of CLRH line, while phase delay arises in the right-handed (RH) frequency band. The change of the fluid’s properties that flow in the microfluidic reservoir causes the change of effective permittivity of the microstrip substrate, and subsequently the phase velocity changes, as well as the phase shift. This effect was used in the design of the microfluidic sensor for the measurement of characteristics of the fluid that flows in the microfluidic reservoir placed under the CLRH line. The complete measurement system was developed including the Wilkinson power divider that splits the signal between conventional RH and CLRH section, transmission lines with the microfluidic reservoirs, and a detection circuit for phase shift measurement. Measurement results for different fluids confirm that the proposed sensor is characterized by relatively high sensitivity and good linearity (R2 = 0.94). In this study, the practical application of the proposed sensor is demonstrated for the biomass estimation inside the microfluidic bioreactors, which are used for the cultivation of MRC-5 fibroblasts.


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