A double folded-slot antenna at 94 GHz

We have designed, fabricated and tested a double folded-slot (DFS) antenna at 94 GHz. This antenna is easily fed using a coplanar-waveguide (CPW) transmission line and is therefore a candidate for uniplanar circuit implementations. The DFS exhibits a very wideband input impedance of 20 /spl Omega/ based on moment method computations. Placing the antenna on a dielectric lens eliminates substrate mode problems and results in high gain beam patterns. Measured patterns at 94 GHz show a symmetrical main beam and low side-lobe levels. The application areas for the double folded-slot are wideband transistor-based receivers, transmitters, and imaging arrays for millimeter-wave sensors such as active seekers, automobile collision-avoidance radars and aircraft landing systems.