Measurement of rectifying diode impedance and efficiency for energy harvesting applications

Abstract

In this paper we present a new procedure for wide-band measurement of the zero-bias Schottky diode impedance and rectified DC voltage. Measurement is performed with MS4647A VectorStar VNA (Vector Network Analyzer) and Rigol DS1054z oscilloscope in the frequency range 0.5 - 5 GHz. The RF input power is varied from -25 to 5 dBm and several different values of load resistance is used. Since measurement required definite power levels at the diode ports, both S-parameter calibration and nonlinear power calibration of VNA were applied. S-parameter calibration was performed at three different reference planes using SOLT (short open load thru) and LRL (line reflect line) calibration algorithms. Measured complex conjugate values of the diode impedance are compared with the optimum diode input impedance that are obtained via Harmonic Balance simulation.