A Wide band Calorimeter for R.F. Power Measurements at 3 cm

The paper describes a calorimeter (consisting of a water load and thermocouple unit) designed for the measurement of r.f. power at 3 cm, where the mean power range involved is 5¿200 watts. The design and performance of a water load providing a good match to the guide over a wide frequency band (8% in the 3-cm range is given. Details are also given of a satisfactory thermocouple unit which can be used on both 10 and 3 cm, and relevant precautions in manufacture and operation discussed.