scholarly journals Miniaturized Antenna Solution Based on Lossy Planar Microresonators to Conjointly Control Radiation and Selectivity

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Biyun Ma ◽  
Anne Chousseaud ◽  
Serge Toutain
Keyword(s):  
Quality Factor ◽  
Filter Design ◽  
Radiation Loss ◽  
Distributed Load ◽  
Air Resistance ◽  
Miniaturized Antenna ◽  
Specific Frequency ◽  
Unloaded Quality Factor ◽  
First Time ◽  
Basic Radiation

We propose a new method to design miniaturized compact antennas, in which it is possible to control conjointly the radiation efficiency and the bandwidth selectivity of the antenna. And this method has been validated by the realization of prototypes based on planar resonators. The geometry of these resonators has been chosen because their unloaded quality factor can be controlled and is mainly dependent on radiation loss. In the first time, a filter with a significant potential to radiation has been realized by choosing suitable miniaturized resonators. An antenna, based on the same structure, in which the output of the filter was removed (load by air resistance) can be obtained. Modification of the quality factor of each resonator is necessary to take into account the change of the load value from the previous filter to the final structure. The position and the quality factor of the resonators are determined by a filter design concept to obtain a specific frequency response in which each resonator is a basic radiation element. Load of the antenna is ultimately a distributed load constituted by the parallel contributions of each resonators to radiation loss. In other words such an antenna can also be called radiating filter.

Polaron conduction loss in microwave dielectric ceramics

1999 ◽  
Vol 14 (2) ◽  
pp. 500-502
Author(s):  
Seungbum Hong ◽  
Eunah Kim ◽  
Han Wook Song ◽  
Jongwan Choi ◽  
Dae-Weon Kim ◽  
...  
Keyword(s):  
Quality Factor ◽  
Phonon Scattering ◽  
Dielectric Resonators ◽  
Frequency Range ◽  
Conduction Loss ◽  
Microwave Dielectric ◽  
Scattering Effects ◽  
Unloaded Quality Factor ◽  
Dielectric Ceramics ◽  
Polaron Conduction

It has been generally accepted that the product of the unloaded quality factor and resonant frequency is the universal parameter for comparison of dielectric resonators with different size.1,2 However, it is suggested in this study that this universal parameter should be modified due to the presence of the polarons. From the frequency dependence of the unloaded quality factor, it is possible to extract the factor determined only by the phonon scattering effects, and we denoted this parameter by Qs. It was found that the Qs parameter for ZrxSnzTiyO4 (ZST) and Ba(Zn1/3Ta2/3)O3 (BZT) ceramics showed constancy in the frequency range of 2–12 GHz, which supports the idea of polaron conduction loss contribution to the dielectric loss.

Shape optimization of a dielectric resonator for improving its unloaded quality factor

2010 ◽  
Vol 21 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Hassan Khalil ◽  
Stéphane Bila ◽  
Michel Aubourg ◽  
Dominique Baillargeat ◽  
Serge Verdeyme ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Quality Factor ◽  
Dielectric Resonator ◽  
Unloaded Quality Factor

Performance Improvement of RF Inductors Using LTCC Technology

2011 ◽  
Vol 2011 (CICMT) ◽  
pp. 000054-000058 ◽  
Author(s):  
Goran Radosavljević ◽  
Andrea Marić ◽  
Walter Smetana ◽  
Ljiljana Živanov
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Design Optimization ◽  
Quality Factor ◽  
Performance Improvement ◽  
Air Gap ◽  
Frequency Range ◽  
Operating Frequency Range ◽  
Rf Inductors ◽  
First Time

This paper presents for the first time a parallel comparison of the performance of RF inductors realized on different substrate configurations. Presented inductors are meander type structures fabricated in Low Temperature Co-fired Ceramic (LTCC) technology. Also, chosen material is never before implemented for inductor fabrication. The performance improvement is achieved by design optimization of different substrate configurations that incorporate placement of an air-gap beneath the inductor and/or introduction of an additional shielding layer on the top. Designed structures are characterized on the basis of simulation and experimental data, achieving good correlation between obtained results. Presented results show over 30 % increase in quality factor and widening of the operating frequency range by over 55 %.

scholarly journals A Novel System Analysis Methodology: Transform Method, Relation Spectrum, and System Filter

2020 ◽  
Author(s):  
Gang Liu ◽  
Jing Wang
Keyword(s):  
Neural Network ◽  
System Identification ◽  
System Analysis ◽  
Fourier Spectrum ◽  
Filter Design ◽  
Medical Application ◽  
Simulation System ◽  
Transform Method ◽  
Analysis Methodology ◽  
First Time

We have presented a controllable and human-readable polynomial neural network (CR-PNN) that is the first human-readable neural network. One can imagine its influence on system identification. Subsequently, we developed a relation spectrum in a medical application, which is likely to stand alongside the Fourier spectrum. However, the system analysis methodology is incomplete in contrast to signal processing methodology. Here, we presented the system filters for the first time. In this paper, we used the simulation system to verify the availability of the system analysis methodology. The system analysis methodology showed great properties in system identification and filter. The contribution of this paper is the system analysis methodology: transform method (CR-PNN), relation spectrum, and system filter design.

scholarly journals Quality Factor Enhancement of 650 MHz Superconducting Radio-Frequency Cavity for CEPC

2022 ◽  
Vol 12 (2) ◽  
pp. 546
Author(s):  
Peng Sha ◽  
Weimin Pan ◽  
Jiyuan Zhai ◽  
Zhenghui Mi ◽  
Song Jin ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Quality Factor ◽  
Microwave Surface Resistance ◽  
Medium Temperature ◽  
Residual Resistance ◽  
Electron Positron ◽  
Superconducting Radio Frequency ◽  
Unloaded Quality Factor ◽  
Srf Cavity ◽  
Vertical Test

Medium-temperature (mid-T) furnace baking was conducted at 650 MHz superconducting radio-frequency (SRF) cavity for circular electron positron collider (CEPC), which enhanced the cavity unloaded quality factor (Q0) significantly. In the vertical test (2.0 K), Q0 of 650 MHz cavity reached 6.4 × 1010 at 30 MV/m, which is remarkably high at this unexplored frequency. Additionally, the cavity quenched at 31.2 MV/m finally. There was no anti-Q-slope behavior after mid-T furnace baking, which is characteristic of 1.3 GHz cavities. The microwave surface resistance (RS) was also studied, which indicated both very low Bardeen–Cooper–Schrieffer (BCS) and residual resistance. The recipe of cavity process in this paper is simplified and easy to duplicate, which may benefit the SRF community.

A multilayer substrate integrated filter using dual dielectric modes

2019 ◽  
Vol 11 (08) ◽  
pp. 787-791
Author(s):  
Xiao-Xiao Yuan ◽  
Li-Heng Zhou ◽  
Jian-Xin Chen
Keyword(s):  
Printed Circuit Boards ◽  
Filter Design ◽  
Center Frequency ◽  
Circuit Boards ◽  
Dual Mode ◽  
X Band ◽  
Compact Size ◽  
Unloaded Quality Factor ◽  
Multilayer Substrate ◽  
Good Agreement

AbstractIn this paper, a novel multilayer substrate integrated dual-mode dielectric resonator (DR) filter is proposed. The square dual-mode DR is made of the high permittivity substrate by removing the undesired portions and the surface coppers so that the relatively high unloaded quality factor of the dominate TM11 pair can be obtained which compared to these fully dielectric-filled substrate integrated waveguides. Meanwhile, it can be easily integrated in an equivalent cavity implemented by multilayer printed circuit boards for filter design, showcasing low in-band loss, light weight, and compact size. For demonstration, a multilayer substrate integrated DR bandpass filter centered at X-band is designed and measured. Good agreement between the simulated and measured results can be observed, and the measured insertion loss at the passband center frequency (8.38 GHz) is 1.1 dB.

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