A passive-type even harmonic quadrature mixer using simple filter configuration for direct conversion receiver

A passive-type even harmonic quadrature mixer using simple filter configuration for direct conversion receiver is presented. All circuits in the mixer are composed of passive elements. Diplexers of this mixer consist of simple high pass and low pass filters enough to realize a mixer with small size. This mixer is suitable for a mobile handset, because no DC consumption is required and it is easy to design and manufacture from its simple configuration. A developed mixer achieved good RF characteristics for direct conversion receivers.