The design of W-band folded waveguide TWT was completed. Two numbers of leak tight gun stacks, one collector assembly and one rectangular block with 600-micron beam hole were fabricated. One beam stick tube with electron gun stack, rectangular block and collector were integrated to optimise the process of axially aligned integration within 5 micron with leak tight joints (Fig. 1). One W-band RF block was fabricated and characterised for S parameters. One Pill-box type RF window was fabricated (Fig. 2). W-band folded waveguide RF structure was fabricated with SU-8 based X-ray lithography (Fig. 3) from RRCAT, Indore. Removal of SU-8 is under progress at CSIR-CEERI. Development of W-band BWO is also in progress.

Fig. 1: Integrated beak stick TWT

Fig. 2: Pill box Window

Fig. 3: 4 W-band folded waveguide RF structure fabricated at RR_CAT through X-ray lithography