A mechanically simple Foster scanner

This paper describes the design, construction, and testing of a Foster scanner that is much simpler to build than the conventional Foster scanner. The simplifications result from the use of a choke groove and a solid barrier to replace the conventional inter-leaving finger barriers. The choke groove and solid barrier are very simple to construct, give excellent electrical performance, and permit very high scan rates. A scanner has been built and tested at 35 kmc, where the tolerance problems are very severe, and found to perform extremely well over at least a 10 per cent frequency bandwidth.