In a joint project with the Norwegian Polar Institute, we created a portable Vivaldi-style radar antenna. This project was shipped to Antarctica as a supplemental radar assembly.
This project was very interesting, and presented a unique challenge, based on its radar transparency. We normally work with fiberglass, as it is the strongest, most versatile material that is also radar transparent. The green structure seen in the photos below is an extruded, pre-made fiberglass material that we used for our radar mount. We tested this structure multiple times for radar transparency during our design phase.
On the day before shipment, about 10 minutes after close of business, we noticed that the fiberglass was causing some major radar interference. It turns out that this batch of fiberglass had other materials in it! we could not get our radar to function properly. With hours before shipment, we needed to come up with another design! Luckily, we were able to fix the mount with this fiberglass material by mounting only on the edges. While this was an all night project, we were able to ship on time the next morning.
Lesson learned! No matter how much you test your materials, test the final batch that you are using, and do so well in advance of your deadline!