Abstract :
The paper is a survey of some problems and techniques involved in radio communication at wavelengths below 30 cms. and is concerned largely with the methods by which continuous oscillations may be generated in this region. Consideration of the difficulties attending the use of conventional methods in the hyperfrequency range is followed by a discussion of the ways in which triodes may be employed at short wavelength, by suitable modifications in the design of valves and circuits. A section on the magnetron is followed by descriptions of valves using resonant cavities as circuit elements, and after reference to the propagation and reception of hyper-frequency signals, the paper concludes with some speculations as to the future developments in the centimetre-wave region.