Effect of Various Delay Line Ratios and Their Non-Linearity on the Performance of DIFM

The electronic warfare (EW) receiver’s frequency measurement precision is dependent on the accuracy of the delay line ratio and phase. A mathematical equation has been derived for accounting the effect of non –linearity due to inaccuracy in delay line ratio and phase. The effect of phase non-linearity (i.e., the combined effect of inaccuracy in delay line ratio and phase) on the output frequency is simulated using MATLAB. Analysis has been carried out for equal and unequal adjacent delay line ratios. Digital instantaneous frequency measurement (DIFM) receiver module has been realized for 9 GHz (1-10 GHz) bandwidth and is verified practically. Results are in good agreement with each other even in different environmental conditions.