This thesis deals with design and optimization of monolithically integrated circuits for applications at microwave frequencies fabricated in a state-of-the-art low-cost silicon germanium (SiGe) bipolar technology. Monolithic integration of analog building blocks is demonstrated on the basis of three representative circuits for different microwave applications.
The first circuit presented in this work is a broadband amplifier. The main application of this amplifier is as a preamplifier of high data rate signals. A flat frequency response and a high 3-dB bandwidth are the main design targets. By careful optimization of the circuit, outstanding measurement results up to 100 Gbit/s are achieved. This is the highest bit rate for analog high-frequency circuits published so far for silicon-based as well as GaAs and InP technologies.
The second example of a fully monolithically integrated microwave circuit is a down-conversion mixer in the frequency range from 76 GHz to 81 GHz. This frequency band is intended for automotive distance sensors.
With this design, a monolithically integrated active down-conversion mixer for microwave frequencies around 77 GHz is demonstrated for the first time in silicon-based technologies.
Finally, a voltage-controlled oscillator is shown. The main design target is to reach an output frequency as high as possible at reasonable values of phase noise and output power. By application of innovative circuit concepts like a quarter-wave transformer at the output of the circuit an operation frequency up to 98 GHz is reached.