Improving SNR of radiation detector readout electronics
Objectives: Solid-state radiation detectors have advantages of size and low voltage, but often suffer from noise artifacts. We sought to develop flexible readout methods to improve signal-to-noise ratio (SNR) for such detectors.
Methods: Readout strategies were evaluated for increasing signal-to-noise ratios in circuits intended for active-pixel-sensor (APS) detectors (e.g., as in Medipix arrays). An additional amplifier element was inserted into the traditional three-transistor integration circuit, in order to decouple the intrinsic capacitance of the radiation detector from the charging capacitor. SNR from the resulting circuit was compared to traditional APS integrating circuits during exposure to x-rays with 75-keV peak energy.
Results: Experimental measurements demonstrated approximately ten-fold improvement in SNR for the four-transistor integration circuit as compared to traditional APS systems.
Conclusions: Signal-to-noise ratio for solid-state radiation detectors can be improved through additional pixel-based amplifier stages.