Advanced Calibration Techniques for VNAs

Traditional Polynomial-Based Models• Lossy transmission line terminated with either…– a frequency-dependant impedance for opens and shorts– a perfect load (S 11 = 0)Z char , offset delay, offset lossopen short loadTransmission lineZ t• Third-order polynomial models for Z t :– Open capacitance:C(f) = C 0 + C 1 *f + C 2 *f 2 + C 3 *f 3– Short inductance:L(f) = L 0 + L 1 *f + L 2 *f 2 + L 3 *f 3CAdvanced VNA Calibration© Agilent Technologies, Inc. 2006 Page M6- 31f