Micromachined Antennas for Integration with Silicon Based Active Devices

In this thesis micromachined antennas suitable for on-chip integration with silicon based active devices are treated. The emphasis is put on compact 24 GHz antennas, capable of being integrated in commercial SiliconGermanium (SiGe) processes using low temperature post processing micromachining techniques. Antenna types covered are the slot loop antenna, wire loop antenna, meandered dipole and the inverted F antenna. The antennas have been implemented on surface and bulk micromachined low resistivity silicon substrates. It is found that the bulk micromachining method yields antennas with improved efficiency compared to antennas relying on thick dielectrics for reduction of substrate losses. Two patch antennas, suitable for wafer level integration with actice devices are covered. A 60 GHz micromachined aperture coupled patch antenna with a bandwidth of 59-64 GHz is presented. A novel 24 GHz differentially fed patch antenna, manufactured using a thick organic dielectric, is modelled with a modified transmission line method. Low Temperature Co-fired Ceramic (LTCC) and glob-top packaging for integrated antennas is evaluated. Epoxy based glob tops are found to have lower losses than silicone based ones. Finally, crosstalk between the integrated antenna and simple on-chip wire interconnects is analyzed by simulations for slot antennas manufactured in a SiGe process. It is noted that by proper connection of the antenna to the semiconductor substrate a high degree of isolation can be obtained.