Approach of Pulse Parameters Measurement Using Digital IQ Method

Abstract

 Abstract—Electronic Warfare (EW) systems measuring the radar parameters using conventional method can't preserve phase information of the incoming Radio Frequency (RF) signals. Conventional methods does the measurement using detected video signal or envelope of the RF. Proposed method does the measurement using intermediate frequency (IF) signal which is the down converted signal of RF signal. This method preserves the phase information because the intrapulse and interpulse measurements are carried out using the IF signal. The Matlab simulation is carried out for the intrapulse analysis and results are presented and discussed. The comparison is given between conventional method and proposed method for Radar EW systems. Initially the measurement of radar pulse parameters being carried out using the envelope of the down converted IF or RF signal. This envelope is nothing but it is video signal. In the process of envelope detection, the phase information of the signal is lost. Therefore these methods are not useful where phase information is to be preserved. The proposed EW receiver is shown in the Fig. 2. The next generation EW receiver is the superhet receiver. The superhet receiver downconverts the RF signal into the fixed IF signal of the required bandwidth. The bandwidth is varied depending upon the requirements. The superhet receiver has the advantage of sensitivity due to its limited bandwidth. The proposed method of intrapulse analysis works alongwith the superhet receiver. The IF generated from the superhet receiver is digitized. The frequency translation is carried out on these digitized IF samples and filtered out the highest component. This method measures the rise time and fall time and it also carries out measurement of parameter variations within the pulse.