Temperature Dependence of the Subthreshold Characteristics of Dynamic Threshold Metal–Oxide–Semiconductor Field-Effect Transistors and Its Application to an Absolute-Temperature Sensing Scheme for Low-Voltage Operation

Abstract

Communicated by B. F. J. Schonland ; MS. received 5thJuly 1956 and in revised form 26th February 1957 satlonal Telecommunications Research Laboratory of the South African Council for,@styact. Radar observations, on a wavelength of 50 cm, of inter-stroke lightning processes provide the following information on the nature of the charged column and the manner in which it is discharged: (a) Inter-stroke junction streamer activity is most intense and most prolonged in the lower regions, that is, at heights ranging from 4-7 km. (b) Vertical development of the junction streamers may on occasion take place steadily to a height of about 10 kilometres. The velocities are in good agreement with those derived by Malan and Schonland. The junction streamer activity is somewhat less Intense in the upper regions and tends to disappear while activity still persists In the lower regions. (c) The lower height limit of junction streamer activity remains at a more or less constant height throughout the flash. ( d ) The horizontal extent of the junction streamer activity in the lower regions is frequently of the order of 14-2 kilometres. (e) The echoing properties of the junction streamers actually decrease during the latter part of the inter-stroke period and a further stroke does not occur until this decrease has taken place. (f) A stroke may take place from one or more regions in the charged column, without affecting appreciably the junction streamer process in another region which will nevertheless contribute to a later stroke in the same lightning discharge.Modifications to the tentative description of the inter-stroke processes given by Malan and Schonland are suggested which would explain these results.Some information has been gained on the nature and intensity of the noise radiated by lightning at 600 Mc/s. I n particular it appears that at this frequency the noise is radiated from comparatively localized sources and may possibly be associated with the stepped and dart leader processes.