60 GHz circularly-polarized smart antenna system for high throughput two-dimensional scan cognitive radio

Cognitive radio front-end design over 60 GHz frequency range is highly dependent on the performance of antenna front end. This work presents a novel technique to design fixed beam-forming smart antenna with four independent orthogonal beams. Vertical interconnect proposed in substrate integrated waveguide (SIW) technology is used to design the space saving beam-forming network. Analog phase shifter based on Butler matrix is used to drive the radiating aperture. The complete phased array system is fabricated by using low-cost PCB technology. For each input port, 60 GHz right hand circularly polarized (RHCP) smart antenna gain is measured as 13 dBc. The designed RHCP phased array system is able to form beams in two dimensional (2-D) scan space. The designed V-band smart antenna system with circularly polarized scanned patterns will satisfy today´s cognitive radio front-end requirements.