THRESHOLD DETECTION METHOD FOR OPTICAL SIGNALS Russian patent published in 2023 - IPC G01R19/175 H01L31/107 

FIELD: reception of signals.

SUBSTANCE: invention is related, in particular, to the technique of separating signals from noise using avalanche photodiodes and can be used in location, communications and any field where the best real sensitivity is required. A method for threshold detection of optical signals using an avalanche photodiode, including threshold processing of signals and generation of output pulses using a threshold device when the signal from the output of the photodiode exceeds a predetermined response threshold. The avalanche-free mode of the photodiode is pre-set by applying a low bias voltage to it and the threshold level for noise frequency exceeding the threshold f is stabilized, then the threshold is fixed at this level, increased by x₁ times and the bias voltage is increased until the frequency of noise exceeding the threshold reaches the initial value f, after which the bias voltage of the photodiode is fixed, the threshold level is increased by x₂ times, moreover, the parameters of the threshold increase are set equal to x₁ = x₂ = x = √ (1+2/α), the frequency f is set in accordance with the ratio f = f₀^(2/2+α) · f_p^(2/2+α), where α is the coefficient determined by the material of the photodiode, f₀ is the frequency of crossing the zero level by noise, f_p is the maximum allowable frequency of exceeding the threshold by noise emissions in the operating mode, after which signal receipt is started.

EFFECT: simplification of the preparatory mode and provision of the optimal sensitivity in all operating conditions with a guaranteed probability of false positives and maximum performance.

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