Building on the designs from Andrew Anderson VK3CV using a duplexer cavity fitted over the 5x5mm TRA_120_002 radar chip, https://siliconradar.com/products/single-product/120-ghz-transceiver-tra_120_002/ but using threaded adjustment for best match. I'm working on a range of alternative fittings including UG-387/U anti-cocking flanges, reference horns, feedhorns and Chaparral-style choked horns. I'll extend the range of fittings to include WR-08 rectangular waveguide transitions and tapered sections to 1.8mm or smaller round guides as demand arises.The 122GHz band presents extreme challenges to long distance communication because of atmospheric resonances (2nd harmonic of the 60GHz Oxygen resonance) and water vapour absorption. Losses are in excess of 1dB per km. The world record distance for this band is around 60km