Cold-Test of The W-Band Nonperiodic Concentric Arc FW-SWS Based on The Beam-Wave Resynchronization Method

Cold-test of the W-band nonperiodic concentric arc folded-waveguide slow-wave structure (FW-SWS) based on the beam-wave resynchronization method is presented in this paper. The scanning electron microscope result shows that the edge of the concentric arc FW-SWS is clear, where almost no cutting burr can be observed. Moreover, the measured |S
11
| is below −19.5 dB from 90 GHz to 104 GHz, and |S
21
| is in the range of −9.2 dB to −5.3 dB. Furthermore, the cold-test result demonstrates that when the bulk conductivity of copper is set as 4.2×10
⁷
S/m higher than the common value (2.25×10
⁷
S/m) in W-band, the simulated result can be the most consistent with the measured one, which indicates that surface roughness and finish of the fabricated FW-SWS is better than expectation.