A two dimensional lens stack design for 94 GHz

The development of phased array systems is one of the most ambitious research areas for the millimeter wave frequency range. Different approaches have been made in the past to realize phased array antennas for this frequency range. Unfortunately until now no cost effective solutions could be realized. Rotman lenses can be useful as multiple beam forming networks for linear antennas providing the advantage of broadband performance and low production costs. Lens designs like the Rotman lens offer one great disadvantage; they could only realize a linear scan in one dimension. For many applications a two dimensional scan in azimuth and elevation at the same time is necessary. To solve this problem a two dimensional lens stack was realized. This work presents the design and development of a Rotman lens stack at 94 GHz. The construction is completely realized in waveguide technology. Experimental results are compared with theoretical considerations and electromagnetic simulations.