The combiner matrix balun, a transistor based differential to single-ended module for broadband applications

In this paper a new active combing balun, i.e. differential input to single-ended output, with broadband performance, the combiner matrix balun, is presented. Measured results show an amplitude and phase difference of less than 1 dB and 20 degrees from 5 to 40 GHz together with a gain of 2 dB with less than 1 dB ripple. The topology is easily scaled up in frequency and gain and also technology independent making it an interesting choice for future broadband differential applications.