基于周期性延时衔接法的顺序等效采样方法OA

To address the limitations of the sampling timing system delay range in timedomain reflectometry(TDR)instruments for long cable fault testing,a sequential equivalent sampling method based on periodic delay coupling is proposed.A detailed comparison with traditional sequential equivalent sampling methods analyzes the advantages of this approach in terms of delay range and sampling speed.The method employs a programmable delay chip to achieve precise stepped delays of the sampling clock signal,using the maximum delay range of the delay chip to connect multiple cycles of the sampling clock,thus extending the delay range.This approach simplifies the hardware design of the stepped delay circuit while ensuring the precision of the stepped delay,significantly reducing hardware costs.A field-programmable gate array(FPGA)is used to sort the sampled data in chronological order to reconstruct the signal being measured.Experiments are conducted to validate a delay range of 10 µs and a stepped delay precision of 10 ps,which can greatly enhance the performance of TDR instruments in the field of long cable testing.