A 40 GHz/9 ps Sampling Head for Wideband Applications

The purpose of this research is the evaluation and the design of a 40 GHz/9 ps wideband sampling head with commercially available microwave components and without the use of digital compensation techniques or cryogenic cooling techniques. This paper discusses the considerable increase in bandwidth and the novel compensation techniques of the AC-blow-by and initial-charge blow-by of the traveling-wave trapped-charge sampling gate [1] since these are the current limitations of this most promising approach for wideband sampling. The actual circuit is realized on alumina substrate (ϵ
_r
= 9.9, h = 10 mil). The same method was employed on RT/duroid (ϵ
_r
= 10.8, h = 10 mil) which yields an impressive bandwidth of 21 GHz.