A novel structure of single-side-band mixer with adopting dual-band quadrature coupler

This paper presents a novel structure of single-side-band (SSB) mixer with adopting the dual-band quadrature coupler, which is designed to appropriately operate at both RF and IF bands, for reducing the required components of the mixer and minimize the size of circuit. The method of constructing the quadrature coupler with dual band characteristics is proposed. An experimental SSB mixer, which consists of the proposed dual-band coupler, lump-element divider and mixing diodes, was designed and constructed by using conventional PCB technology and SMT devices. The measurement result show conversion losses, which include the loss caused by the coupler, is less than 14dB and the side-band suppression is greater than 33dB while the SSB mixer was operated at IF=120MHz and LO=5.65GHz. The measurement results also show the effectiveness of the proposed SSB mixer structure.