The modified Optical Phase Lock Loop, as suggested in this paper, considerably improve the performance of the microwave signal generation technique over the earlier technique with the help of commercially available DFB lasers with linewidth of about 4.0 MHz. This modified OPLL seems a realistic approach for generating reference signal for future advanced communication systems with active phased array antennas. This opto-electronic technique provides the advantage of low weight, small size, flexible, immunity to EMI and above low cost because the proposed technique significantly reduces the requirement of narrow linewidth lasers. Moreover, it has been observed that bulk and surface acoustic waves in the power and frequency ranges of a few mW and KHz respectively are capable of modifying both the cavity length and refractive index of the material of semiconductor lasers
