A Biasing and Demodulation System for Kilopixel TES Bolometer Arrays

We describe the signal processing logic, firmware, and software for a frequency-domain multiplexed biasing and demodulation system that reads out transition-edge-sensor bolometer arrays for millimeter-wavelength cosmology telescopes. This system replaces a mixed-signal readout back end with a much smaller and more power-efficient system relying on field-programmable gate arrays for control, computation, and signal processing. The new system is sufficiently robust, automated, and power efficient to be flown on stratospheric balloon-borne telescopes and is being developed further for satellite applications.