Modern multistage depressed collectors—A review

Well performing multistage depressed collectors (MDC's) have been developed for traveling-wave tubes (TWT) in an sizes fitting the requirements of wide-band countermeasures, radars, and ground and space communications. In the case of NASA-type symmetric collectors, rigorous analytical tools were developed that permit accurate a priori designs of MDC's for any given helix-type tube. Although only few verified cases of MDC's augmenting communications klystrons are known, the resulting performance and available theories indicate significant gains in reducing power consumption by TV and other klystron amplifiers without the deleterious effects of backstreaming.