Ultra Wideband Power Detector for W-Band Applications Using a Novel Additively Manufactured Wave Mode Transducer

In this paper, a novel additively manufactured broadband end-launch wavemode transducer for WR-10 waveguide to microstrip line (MSL) is presented. Furthermore, a diode power-detector featuring this transition for the entire W-band (75 to 110 GHz) is introduced. This transition incorporates a cos2-shaped septum from the waveguide broad wall down to the MSL on the printed circuit board (PCB). To characterize the propagation properties of the transitions, the S-parameters of a back-to-back measurement setup are determined, achieving a return loss of less than −10 dB over the entire W-band and a maximum insertion loss of −9 dB for a MSL-line length of 50 mm. The detector, utilizing this transducer, exhibits a high linearity and a square-law behaviour to signal powers smaller than −10 dBm. Measurements suggest promising performance for applications in the field of measurement and demodulation, especially when multiple detectors are needed, e.g. in six-port assemblies.