Propagation Studies at Microwave Frequencies by Means of Very Short Pulses

This experiment was set up with two main purposes in view: First, as a means of studying microwave propagation, especially with regard to multi-path transmission effects and second, to determine the effect, of a transmission path upon the shapes of very short pulses, particularly to learn what restrictions might be imposed upon minimum pulse length or sparing between pulses by distortions produced in the transmission medium. In regard to multi-path transmission the pulse method seems to be the most straightforward way of studying such effects. For example, if there is transmission by more than one path, and if the pulses are sufficiently short in comparison to the path length differences involved, then there will be received a separate pulse for each path. Under these conditions the number of paths involved, path length differences and other information become directly evident. If pulse duration is too great with respect to the path differences involved, the pulses received via the various paths will overlap in time and the resultant multi-path effect will be pulse distortion rather than reception of individual pulses. This situation is much more difficult to analyze. TRANSMISSION PATH