Vaccaro D, Akamatsu H, van der Kuur J, van der Hulst P, Nieuwenhuizen A C T, van Winden P, Gottardi L, den Hartog R, Bruijn M P, D'Andrea M, Gao J R, den Herder J W A, Hoogeveen R W M, Jackson B, van der Linden A J, Nagayoshi K, Ravensberg K, Ridder M L, Taralli E, de Wit M
NWO-I/SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands.
NWO-I/SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands.
Rev Sci Instrum. 2021 Mar 1;92(3):033103. doi: 10.1063/5.0032011.
In the frequency-domain multiplexing (FDM) scheme, transition-edge sensors (TESs) are individually coupled to superconducting LC filters and AC biased at MHz frequencies through a common readout line. To make efficient use of the available readout bandwidth and to minimize the effect of non-linearities, the LC resonators are usually designed to be on a regular grid. The lithographic processes, however, pose a limit on the accuracy of the effective filter resonance frequencies. Off-resonance bias carriers could be used to suppress the impact of intermodulation distortions, which, nonetheless, would significantly affect the effective bias circuit and the detector spectral performance. In this paper, we present a frequency shift algorithm (FSA) to allow off-resonance readout of TESs, while preserving the on-resonance bias circuit and spectral performance, demonstrating its application to the FDM readout of an x-ray TES microcalorimeter array. We discuss the benefits in terms of mitigation of the impact of intermodulation distortions at the cost of increased bias voltage and the scalability of the algorithm to multi-pixel FDM readout. We show that with FSA, in the multi-pixel and frequencies shifted on-grid, the line noises due to intermodulation distortion are placed away from the sensitive region in the TES response and the x-ray performance is consistent with the single-pixel, on-resonance level.
在频分复用（FDM）方案中，过渡边缘传感器（TES）分别耦合到超导LC滤波器，并通过一条公共读出线在MHz频率下进行交流偏置。为了有效利用可用的读出带宽并最小化非线性的影响，LC谐振器通常设计在规则网格上。然而，光刻工艺对有效滤波器谐振频率的精度构成了限制。失谐偏置载流子可用于抑制互调失真的影响，尽管如此，这仍会显著影响有效偏置电路和探测器的光谱性能。在本文中，我们提出了一种频移算法（FSA），以实现TES的失谐读出，同时保持谐振偏置电路和光谱性能，并展示了其在X射线TES微热量计阵列的FDM读出中的应用。我们讨论了以增加偏置电压为代价减轻互调失真影响的好处，以及该算法对多像素FDM读出的可扩展性。我们表明，使用FSA时，在多像素且频率在网格上偏移的情况下，互调失真引起的线噪声被放置在TES响应的敏感区域之外，并且X射线性能与单像素谐振水平一致。
