The influence of the unloaded quality factor of the tunable filter with pin-diodes on the realization of narrow bandwidth

Author(s):  
Chang Zhou ◽  
You-wen Fan ◽  
Rong-hua Yang ◽  
Rong-yu Xu ◽  
Gang Liu ◽  
...  
2018 ◽  
Vol 38 ◽  
pp. 03039
Author(s):  
Chang Zhou ◽  
Chen Ji ◽  
Gen Ping Wu

A technique for tunable filters with low insertion loss and narrow bandwidth is proposed in the form of comb-line structure. Both resonant capacitor with pin-diodes and resonant inductance in the tunable filter were analyzed and the main source of insertion loss was obtained. A series of filters with same pin-diodes, center frequency, absolute bandwidth and low return loss was simulated. The results showed that, by changing the values of the resonant capacitor and inductance, insertion loss of the filter can be greatly restricted. This technique will allow the design of tunable LC filters with low insertion loss and narrow bandwidth.


1999 ◽  
Vol 14 (2) ◽  
pp. 500-502
Author(s):  
Seungbum Hong ◽  
Eunah Kim ◽  
Han Wook Song ◽  
Jongwan Choi ◽  
Dae-Weon Kim ◽  
...  

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.


2010 ◽  
Vol 21 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Hassan Khalil ◽  
Stéphane Bila ◽  
Michel Aubourg ◽  
Dominique Baillargeat ◽  
Serge Verdeyme ◽  
...  

2005 ◽  
Vol 17 (12) ◽  
pp. 2646-2648 ◽  
Author(s):  
Dong Il Yeom ◽  
Hyo Sang Kim ◽  
Myeong Soo Kang ◽  
Hee Su Park ◽  
Byoung Yoon Kim

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Biyun Ma ◽  
Anne Chousseaud ◽  
Serge Toutain

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.


2022 ◽  
Vol 12 (2) ◽  
pp. 546
Author(s):  
Peng Sha ◽  
Weimin Pan ◽  
Jiyuan Zhai ◽  
Zhenghui Mi ◽  
Song Jin ◽  
...  

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.


1998 ◽  
Vol 23 (16) ◽  
pp. 1322 ◽  
Author(s):  
Eung Gi Paek ◽  
Joon Y. Choe ◽  
Tae K. Oh

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