A technique for the continuous indication of waveguide reflection coefficient, impedance or admittance

Apparatus is described which yields a continuous indication of the complex reflection coefficient of a waveguide component, presented in the form of a cathode-ray tube display. The indication is derived from the simultaneous observation of the standing-wave pattern at three or more suitably spaced points by means of a multiple-detector arrangement. A special bolometer element has been developed for this purpose. The equipment is particularly useful for the rapid measurement of v.s.w.r. values close to unity, the accuracy attainable being of the same order as that of a good-quality slotted-section standing-wave indicator. The only specialized microwave component used is the multiple-detector section, a relatively simple and inexpensive unit. Any one detector section may be used over a ±20% range of guide wavelength and the display unit does not require modification.