High-Power Copper Gratings for a Sheet-Beam Traveling-Wave Amplifier at G-band

The design, fabrication, and electromagnetic cold testing results of an all-copper grating circuit intended for a G-band sheet-beam traveling-wave amplifier are presented. Fabrication was carried out via ultraviolet photolithography (UV-LIGA) using the SU-8 photoresists. Two cold test methods used to characterize the microfabricated circuits are reported and reveal excellent agreement with simulations. This type of all-copper grating also shows potential for use as a high-average-power sharp-cutoff filter.