Demonstration of a Broadband Quasi-Optical Power Distribution and Beam-Steering with Transmit Lens Arrays at 550 GHz

A novel transmit lens array is proposed to provide broadband quasi-optical power distribution and beam-steering capabilities for array architectures in future submillimeter-wave heterodyne instruments. The transmit array is composed of a double array layer of lens antenna elements with high aperture efficiency. To enable broadband and low loss quasi-optical (QO) power distribution, the transmit lens array is coupled with a high aperture efficiency single lens antenna. The high aperture efficiency is achieved by using a recently introduced multi-mode leaky wave feed. The top lens array can be used to achieve beam-steering capabilities when fed coherently and mechanically translated using a piezo-motor. In this contribution, we present the development of a prototype based on a transmit lens array of 7 elements at 450-650 GHz with measurements showing a good agreement with simulations. This prototype demonstrates a quasi-optical power coupling efficiency of nearly 60%. Moreover it also shows beam-steering of a 36dBi directivity beam to few discrete angles up to +/-25 degrees with less than 2dB scan loss.