Development of wide-band push-pull amplifiers using coplanar waveguide and slot line

We report the development of completely uniplanar wide-band balanced push-pull FET amplifiers using slot line and coplanar waveguide. The amplifiers employ broadband uniplanar baluns to achieve the push-pull function over a wide bandwidth. One amplifier, designed in the unconditionally stable region, exhibits a gain of 3.5 to 5 dB over the frequency range of 5.4 to 10 GHz. The other amplifier was designed in the potentially unstable range and achieved a high gain between 10 and 11 dB from 2 to 4 GHz. These results show the feasibility of the push-pull FET amplifier configuration using uniplanar technology for microwave and millimeter-wave integrated circuits and systems.