DU Nian-tong, ZHOU Bin. A relative frequency difference detection method based on TDC[J]. 2016, 35(2): 140-142+146. DOI: 10.13873/J.1000-9787(2016)02-0140-03.
A novel method for relative frequency difference detection based on time-to-digital converter( TDC) is proposed. A TDC with a structure of delay chain combined with reference clock is used to directly digitize the frequency difference value of the signal under test. The measurement system and nonlinear calibration module are implemented on field-programmable gate array( FPGA). To evaluate detection precision of frequency difference
oscillator is used as simulation signals to conduct the experiment. Result shows that the proposed measurement method can reach measurement noise 1 × 10- 8/ Hz to Δf / f. The measurement noise sources are analyzed