Investigation of a method to improve VNA calibration in planar dispersive media through adding an asymmetrical reciprocal device

If a passive asymmetrical reciprocal device is used in addition to short open load thru standards in a two-port vector network analyzer calibration, systematic errors in the calibration kit parameters can be reduced dramatically through numerical optimization to minimize asymmetry after correction. The method is described and the quality of correction assessed using simulated data. Measured results are then presented for calibration on a printed circuit board. Encouraging results and practical limitations are discussed.