Measuring the Impedance and Efficiency of Differentially Driven Microstrip Antenna by Two Balun Methods

Two balun methods for measuring the impedance and efficiency of a differentially driven microstrip antenna with a two-port vector network analyzer are evaluated. It is shown that the non-ideal nature of real baluns will cause measurement errors. This paper proposes and describes the new calibration techniques for the removal of the effects of actual baluns. The balun methods and obtained experimental results are discussed and validated.