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.