A new type of traveling wave antenna is presented. Key features of the antenna are planar, low mass and wide bandwidth of operation. One such antenna was designed for terahertz radiation detection and realized in standard IBM CMOS-SOI process with subsequent MEMS post processing. Measurements performed at 655GHz showed very good agreement with the theoretical predictions based on full wave simulations. The present article describes the antenna physics, design, fabrication and measurement results. © 2013 IEEE.