The existing phase modulation on pulse (PMOP) phase transition detector which used on signal processing of electronic warfare system has a problem on its detection performance, especially with frequency and PMOP method. We analyze the problem on existing PMOP detection method and we propose new implementation method. This PMOP detector is based on digital frequency discriminator (DFD) which use delay line and I/Q mixer. The proposed method combine the radar signal phase change on I channel and Q channel. This method makes it possible to analyze frequency and phase modulation method which is not possible on existing PMOP detector. And from proposed PMOP detection method, we can miniaturize the PMOP detector by using the DFD I/Q output which designed with delay line and I/Q mixer.