Determination of Propagation Constants and Wave Impedance of Non-Reciprocal Networks From Position-Insensitive Waveguide Measurements

A microwave method is proposed to determine the forward and backward propagation constants (
$\gamma ^{+}$
and
$\gamma ^{-}$
) and the wave impedance (
$z_{w}$
) of reciprocal and non-reciprocal microwave networks whose positions are not known within their measurement cells (position-insensitive). The proposed method relies purely on analytical expressions and can also evaluate the reference plane transformation distances. Scattering parameter measurements at the
$X$
-band (8.2–12.4 GHz) of a reciprocal network (a waveguide straight) and a non-reciprocal network (a microwave phase shifter) arbitrarily positioned into their measurement cells were conducted to retrieve
$\gamma ^{+}$
,
$\gamma ^{-}$
, and
$z_{w}$
for validation of our method and testing its position-insensitive property. The importance of the method becomes apparent when compared to conventional methods whose accuracy is based on precise determination of the reference planes.