A Ka-band planar compatible traveling-wave spatial power combining amplifier based on Riblet coupler

This paper presents planar compatible traveling - wave waveguide spatial power combining amplifier in which narrow wall short slot coupler or Riblet coupler is utilized. The divider/combiner are designed on substrate integrated waveguide (SIW) and the coupler is integrated with microstrip circuit. Eigen-reflection method is introduced to simplify the design of short-slot hybrid coupler for improving port matching and expanding bandwidth. TE
_n0
mode conversion at curving tapper section determining the Riblet coupler frequency response are reviewed. A Ka-band (35-40 GHz) two-channel power combining amplifier based on the Riblet coupler is implemented. Linear operation of the amplifier is demonstrated and digital predistortion (DPD) is also introduced to enhance linear output power of the amplifier.