研究成果藝廊 > 李遠哲陣列望遠鏡計畫(YTLA, 原簡稱AMiBA)
研究成果藝廊
李遠哲陣列望遠鏡計畫(YTLA, 原簡稱AMiBA)
Noise/Tone Calibration Plate, YTLA Project |
圖片來源: Derek Kubo
This custom plate assembly was design to generate and distribute 2 to 18 GHz wide-band noise or CW tone for in-situ calibration and test of the I/Q down converters and digital backend correlator system. The plate is mounted on the platform and is controlled remotely via Ethernet.
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The requirements for this noise plate was fairly stringent so as to not adversely affect the extremely sensitive correlator when performing astronomical observations. Measured cross-talk between antenna channels was in excess of 140 dB across the entire 2-18 GHz band. The "Noise ON" to "Noise OFF" isolation was estimated to be 180 dB based on three cascaded Dow-Key SPDT switches, each with 60 dB isolation. The assembly was designed and constructed using recycled parts from the decommissioned AMiBA analog correlator system. Design/assembly/test - Derek Kubo, system test - Ranjani Srinivasan/Kai-Yang Lin. |