Silicon bipolar circuits for gigahertz communication systems mixers, multipliers, modulators

Key elements for digital communication systems have been built on the basis of integrated silicon bipolar circuits. Experimental results are presented on mixers and multipliers suitable for operation for DC up to 10 GHz and above, as well as PSK (phase shift keying) modulators for frequencies up to 5 GHz and the corresponding demodulators. These elements have been obtained by modifications of elementary logic circuits. These elementary logic and analog circuits are performance demonstrators included in test chips for the development of high-speed silicon bipolar technologies, which are now in production with 2-μm lithography and in preproduction with feature sizes less than 2 μm. These technologies are well suited for high complexities of about 50 K gates and beyond. Thus, complex communication systems can easily be integrated on a single chip