Relative permittivity characterization of foliages based on rectangular waveguide

Author(s):  
Ananto E. Prasetiadi ◽  
Achmad Munir
2013 ◽  
Vol 22 ◽  
pp. 148-152
Author(s):  
DHANESH THOMAS ◽  
M. T. SEBASTIAN

Butyl rubber — Ca 4 La 6( SiO 4)4( PO 4)2 O 2 — composites have been prepared by sigma mixing and hot pressing. The relative permittivity of the composites varies from 3 to 5.3 at 1 MHz. All the composites show low dielectric loss of the order of 10−3 at 1 MHz. The experimentally observed values of relative permittivity are correlated with those calculated using various theoretical models. The composites show good temperature stability of relative permittivity.


Author(s):  
Azar Maalouf ◽  
Ronan Gingat ◽  
Vincent Laur

This study examines K-band rectangular waveguide terminations with three-dimensional (3D)-printed loads, and proposes an Asymmetrical Tapered Wedge topology. This geometry shows a good tradeoff between microwave performance and 3D-printing issues (printing directions and support material requirements), thus improving noticeably the reproducibility of the devices. The effect of the density of the 3D-printed load on the reflection parameter of the termination was investigated. Even for a low density, reflection level remained below −27.5 dB between 18 and 26.5 GHz. Reproducibility was demonstrated by the characterization of six loads that were 3D printed under the same conditions. Measurements demonstrate that a maximum reflection parameter level of −33.5 dB can be ensured over the whole frequency band without any post-machining of the 3D-printed devices.


2017 ◽  
Vol 65 (9) ◽  
pp. 3099-3108 ◽  
Author(s):  
Eduardo A. Rojas-Nastrucci ◽  
Justin T. Nussbaum ◽  
Nathan B. Crane ◽  
Thomas M. Weller

2019 ◽  
Vol 9 (6) ◽  
pp. 1118
Author(s):  
Juan Martinez ◽  
Angel Belenguer ◽  
Héctor Esteban

The characterization of communication devices in a certain frequency band can be accelerated if a fast frequency sweep technique is used instead of a discrete frequency sweep. Existing fast frequency sweep techniques are either complex or specific for a certain electromagnetic solver. In this work, a new fast frequency sweep method is proposed that consists in segmenting the device under analysis into simple building blocks. Each building block is characterized with a generalized (multimode) circuital matrix whose elements present a simple and flat frequency response that is interpolated using natural cubic splines with very few points. In this way, the response of each block along the whole frequency band is obtained efficiently and accurately with as many frequency points as desired. Then, the circuital matrices of all the blocks are cascaded and the circuital matrix of the whole device in obtained. The new fast frequency sweep was successfully applied to the analysis of different types of devices (all metallic rectangular waveguide filter, dielectric loaded rectangular waveguide filter, and substrate integrated waveguide filter). The computational times were reduced to 15% or 19%, depending on the device, when compared with a discrete frequency sweep using the same electromagnetic solver.


2012 ◽  
Vol 46 (12) ◽  
pp. 1497-1501 ◽  
Author(s):  
Hassan Soleimani ◽  
Zulkifly Abbas ◽  
Noorhana Yahya ◽  
Hojjatollah Soleimani ◽  
Mohammad Yeganeh Ghotbi

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