This project is now complete. The overall objective of this technology development project was to determine the suitability and applicability of polymer technology for satellite user terminals.
Phase 1 was completed successfully. We demonstrated fabrication of the transmitter bandpass filter at 30GHz without tuning using metallized, injection molded polymer technology. The geometric reproducibility (standard deviation) was a few micro-meters which was much better than the value required (i.e. 10μm) for good yield.
Phase 2 was partially successful. The major challenges encountered in this project were:
a) maintaining accurate circular symmetry (relevant to the horn and polarizer),
b) achieving good contact quality (relevant to the polarizer and OMT),
c) insufficient performance of the particular overmolding assembly design (relevant to the polarizer and OMT) and
d) insufficient mold tooling fabrication and measurement capabilities (in Phase 2 but not in Phase 1).
These areas could benefit from further work.
The major successes of the project were:
a) the selected polymer and metallization combination worked well together,
b) very good surface qualilty in the polymer parts was possible when the tooling was polished,
c) geometric reproducibility was very good (standard deviation typically 4μm for the polymer parts and 7μm for the metallized parts),
d) mold tuning was successful as demonstrated with the polarizer,
e) demonstration that reliable, reproducible low-cost production of wave-guide components is feasible when the tooling is correct and
f) the polarizer and feedhorn worked almost perfectly.
Prototype Ka band front-end assembled from overmolded polymer waveguide components using auxillary flanges and a transition block for connection to the rectangular waveguide ports.
Further work is needed in tooling fabrication, measurement and modification. The mechanical design of the parts and the joining method (overmolding) was adequate in some cases (polarizer) but not others (OMT) but can certainly be improved. There are some possibilities for further cost reduction. Overall we conclude that, with this additional work, the technology is suitable for low-cost, high-volume, precision fabrication of waveguide components.