US Patent 7840104 Ultra-wide band AWG multiplexer

A multiplexing AWG device capable of producing an ultra-wideband, low ripple, flat-top signal is presented. The AWG device includes an AWG unit and a two-section waveguide coupled to the AWG unit. The two-section waveguide has a first section and a second section. The first section produces a signal having a double-peak field profile and has a first input end and a first output end. The second section reduces the phase variation of the signal having the double-peak field profile exiting the first section. The second section has a second input end that is coupled to the first output end. For example, the first section may be a parabolic tapered waveguide and the second section may be a rectangular waveguide.