Frequency domain multiplexing for bolometer arrays

✍ Scribed by Lanting, T.M.; Cho, Hsiao-Mei; Clarke, John; Dobbs, Matt; Lee, Adrian T.; Lueker, M.; Richards, P.L.; Smith, A.D.; Spieler, H.G.

• Book ID: 103852884
• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 178 KB
• Volume: 520
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2003.11.311

✦ Synopsis

Fabrication of arrays of a thousand or more sensors is becoming practical. However, readout of these arrays remains a major instrumental challenge. We address this challenge using frequency-domain multiplexing of signals from an array of superconducting transition-edge sensors (TES). Each TES sensor is connected in series with an LC tuned circuit and biased with an alternating current at a selected frequency, ranging from 380 kHz to 1 MHz.The signal from each sensor amplitude-modulates its respective bias current. The LC filter reduces the bandwidth of the Johnson noise from the remaining sensors. The signals are combined at a current summing node and measured with a single superconducting quantum interference device (SQUID) array (100 elements). We have developed a custom SQUID controller with a measured slew rate of 10 7 F 0 /s at 1 MHz.

We designed and fabricated photolithographed LC filters. With these filters we have demonstrated multiplexing with two TES sensors and are preparing to scale up to 32 sensors.