Proposed new waveguide standard of reflection coefficient

A new standard of reflection coefficient for accurate waveguide measurements is proposed. It consists of a short length of dielectric-filled waveguide. It is shown that such a device, backed by a matched load, can have a reflection coefficient whose magnitude is almost constant over a 40% bandwidth. Permittivity values for dielectric materials may now be measured with an accuracy adequate for most applications of the new component. However, an alternative calibration technique is proposed in which a priori knowledge of the permittivity of the dielectric medium is not required.