A compact high-temperature superconducting band-pass filter with wide upper stopband

2019 ◽  
Vol 557 ◽  
pp. 1-6 ◽  
Author(s):  
Hongwei Yue ◽  
Hanxue Tang ◽  
Chaofei Wu ◽  
Qinglian Xie ◽  
Cheng Li
2013 ◽  
Vol 392 ◽  
pp. 672-675 ◽  
Author(s):  
Jian Chang Du ◽  
Lai Yun Ji ◽  
Li Juan He

A high-temperature superconducting (HTS) band-pass filter centered frequency at 127.5MHz was successfully designed and developed. The HTS filter is 14-pole, adopting compact symmetrical dual-spiral resonators. The filter was fabricated on a 3-inch-diameter 0.5-mm-thick LaAlO3 wafer with double-sided DyBa2Cu3O7 thin films. Through the low temperature test, the insertion loss of the HTS filter is under 0.1dB, the bandwidth is 20 MHz, the return loss is better than-22dB and the out-of-band rejection is greater than 80dB. The filters measurements agree well with the simulation.


2014 ◽  
Vol 03 (01) ◽  
pp. 1450003 ◽  
Author(s):  
P. BOLLI ◽  
L. CRESCI ◽  
F. HUANG ◽  
S. MARIOTTI ◽  
D. PANELLA

A planar band-pass filter based on High Temperature Superconductor (HTS) has been designed for possible implementation in the cryogenic front-end of the C-band receiver for the Sardinia Radio Telescope. The band-pass filter is designed to operate at relatively high frequencies: center frequency 6.7 GHz with 30% bandwidth. Seven nominally identical filters have been fabricated to test different carrier materials and connector types aimed to keep the fabrication of the HTS filter simpler and more cost competitive. In addition to the conventional approach, silver plating, copper carriers and SMA connectors have been used. Cryogenic scattering parameter measurements show a good agreement with numerical results: the average of the transmission losses turns out to be in the range 0.15–0.25 dB depending on the prototypes, whereas the reflection coefficient is below -16 dB. The insertion loss has been also measured by using a radiometric approach based on the cold attenuator method showing consistent results with those given by the Vector Network Analyzer. Multiple cool-down measurements have been performed successfully proving the data repeatability both in short- and medium-term. Concerning alternative technical solutions, the SMA connectors and silver plating appear to be valid options whereas the copper carriers are inclined to destroy the circuit. Finally, numerical simulations and experimental measurements on a traditional copper filter operating at 20 K show that the HTS filter improves the losses of about 0.2 dB with respect to the copper one.


2015 ◽  
Vol 2 (3) ◽  
Author(s):  
Tatsuo Ohmachi ◽  
Shusaku Inoue ◽  
Tetsuji Imai

The 2003 Tokachi-oki earthquake (MJ 8.0) occurred off the southeastern coast of Tokachi, Japan, and generated a large tsunami which arrived at Tokachi Harbor at 04:56 with a wave height of 4.3 m. Japan Marine Science and Technology Center (JAMSTEC) recovered records of water pressure and sea-bed acceleration at the bottom of the tsunami source region. These records are first introduced with some findings from Fourier analysis and band-pass filter analysis. Water pressure disturbance lasted for over 30 minutes and the duration was longer than those of accelerations. Predominant periods of the pressure looked like those excited by Rayleigh waves. Next, numerical simulation was conducted using the dynamic tsunami simulation technique able to represent generation and propagation of Rayleigh wave and tsunami, with a satisfactory result showing validity and usefulness of this technique. Keywords: Earthquake, Rayleigh wave, tsunami, near-field


Optik ◽  
2021 ◽  
Vol 226 ◽  
pp. 165924
Author(s):  
Shantanu Mandal ◽  
Kousik Bishayee ◽  
Arindum Mukherjee ◽  
B N Biswas ◽  
Chandan Kumar Sarkar

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