To find the optimum location of an active device i.e., Gunn diode in the Active tapered Slot-Ring Antenna (ASRA) equivalent {ABCD} matrix parameters has been used, so that the best performance in antenna characteristics is realized in terms of power radiated and power received. Microstrip tapered slotring antenna was fabricated by using a 0.787mm thick Takonic TLY-5-0310-CH/CH substrate with r = 2.2 and the active device used is commercially available low power MA/COM packaged Gunn diode (MA 49104) with typical dc to rf conversion efficiency of approximately 1.5% for experimental study. Radiation pattern and locking characteristics of the ASRA have been measure and presented in support of the analytical methods.