Beam forming network design for cluster feeding of highly functional scanning antenna

Electric beam scanning reflector antennas provide beam scanning and pattern control, and can create narrow beams efficiently. However, they are not po pular because the beam control circuit is large and difficult to realize. T his paper proposes a new BFN configuration for cluster feeding of highly fu nctional scanning antenna. The Enhanced PAttern Control nonswiTch (EPACT) B FN simplifies the beam control circuit and its control algorithm by using a fast Fourier transform (FFT) circuit, phase shifters, and a power divider. Furthermore, this paper proposes a design technique that uses modules to i mplement the FFT circuit and a method that optimizes amplifier placement to improve antenna efficiency. The design technique facilitates the manufactu re of large-scale FFT circuits. The optimized amplifier location improves t he antenna efficiency by eliminating the partial concentration of signal po wer.