| Popis: |
For applications at submillimetre wavelengths, an increasing emphasis is being made on more integrated front-end circuits, in which semiconductor devices plus components of the embedding structures in which they are mounted are formed as part of the same fabrication process. The work reported here concerns the development of micromachined Schottky barrier diode devices, photolithographically formed waveguide cavities and their potential for integration. Micromachined millimetre wave rectangular waveguide components have been fabricated in the negative epoxy based photoresist SU-8. Inductive iris and E-plane septa band-pass filters (centre frequency 135GHz) with respective bandwidths of 5% and 10% were formed using this low-cost method. Using dual layer SU8 processing, accurate positioning of all micromachined waveguide components within standard two-port and three-port RF test fixtures was achieved. A 6dB branch-line coupler operating at 220GHz has also been realised and similar techniques are currently being applied to micromachined rectangular waveguide tuning structures. The methods employed are suitable for sub-millimetre wave application and waveguide components operating at frequencies approaching 1THz have been fabricated. |
