A 220–330-GHz Broadband Subharmonic Mixer With Linear Gradient Probes

This letter introduces the design of a novel broadband subharmonic mixer operating at 220–330 GHz, which can be applied in the fields of spectrum analysis and wireless communication systems. The device achieves frequency mixing through a pair of Schottky diodes and adopts a linear gradient probe structure, which has the remarkable feature of a wide operating band in the terahertz band, providing a new way of thinking for the design of ultrawideband terahertz mixers. The measured results show that the typical single sideband (SSB) conversion loss of the broadband subharmonic mixer is 11 dB in the RF frequency range of 220–330 GHz and the minimum conversion loss is 8.7 dB at 300 GHz.