This thesis focuses on two main subjects; mm-wave and THz on-chip antennas
for imaging, signal generation and radiometry applications and tunable high performance
circuits for cellular communications.
First, three on-chip antennas designed at 360 GHz for imaging, designed at 375
GHz for THz signal generation and designed at 160 GHz for radiometry are presented.
The antennas are implemented in commercially available integrated circuit (IC) processes
following an approach which does not required post processing on the silicon
chip after fabrication. For all three antennas the radiating structures are isolated from
the lossy silicon by a ground and loaded by a superstrate for enhanced gain and efficiency.
In commercial IC processes metal fill structures are included in the designs to comply with the strict fabrication rules and a new approach has been proposed on
placing the metal fills to enhance the gain and efficiency further.
Second, two different tunable circuits have been designed for cellular systems.
First circuit is a tunable phase shifter designed incorporating a tunable coupler which
allows operation over a wide frequency range to meet the requirements of future communication
systems. Second circuit is a tunable notch filter designed to be planar for
small volume and very low-loss for high performance. RF MEMS devices are used
as tuning elements in both circuits to get the low-loss performance and high linearity
required by modern communication systems.