Instruments for use in the microwave band

The paper describes the instruments used in the microwave band for the measurement of power, frequency and impedance; the majority of them use waveguide methods of transmission, but coaxial systems at the longer wavelengths and free-space semi-optical systems at the shorter wavelengths are also described. Emphasis is laid upon more recent instruments and on those for the millimetre-wavelength region. Methods of manufacture and their influence on behaviour and design are also discussed.