A high temperature superconductor notch filter for the Sardinia Radio Telescope
Journal
EXPERIMENTAL ASTRONOMY
Date Issued
2018
Author(s)
BOLLI, Pietro
•
CRESCI, Luca
•
Huang, Frederick
•
MARIOTTI, SERGIO
•
PANELLA, Dario
Abstract
A High Temperature Superconductor filter operating in the C-band between 4200 and 5600 MHz has been developed for one of the radio astronomical receivers of the Sardinia Radio Telescope. The motivation was to attenuate an interference from a weather radar at 5640 MHz, whose power level exceeds the linear region of the first active stages of the receiver. A very sharp transition after the nominal maximum passband frequency is reached by combining a 6th order band-pass filter with a 6th order stop-band. This solution is competitive with an alternative layout based on a cascaded triplet filter. Three units of the filter have been measured with two different calibration approaches to investigate pros and cons of each, and data repeatability. The final performance figures of the filters are: ohmic losses of the order of 0.15-0.25 dB, matching better than -15 dB, and -30 dB attenuation at 5640 MHz. Finally, a more accurate model of the connection between external connector and microstrip shows a better agreement between simulations and experimental data.
Volume
45
Issue
2
Start page
165
Issn Identifier
0922-6435
Ads BibCode
2018ExA....45..165B
Rights
open.access