Optimization of microstrip tapered balun for sinuous antenna feeding circuits

摘要

In this paper, we present optimization of microstrip tapered baluns that used in frequency independent antennas such as sinuous and spiral antennas. In this method, tapering profile of the baluns is optimized so that to achieve better matching results for input impedance of coaxial cable to balanced antenna input impedance with a shorter length of baluns. For this purpose we've used an optimized non-linear transducer where continuous variations in the transmission characteristics along it, provides an optimum balance-to-unbalance. Applicability of these baluns has been simulated with Ansoft HFSS. Measurement results for a dual polarized planar sinuous antenna in the 2–18GHz frequency range, exactly match with theory and simulation results.