Grant: Research Tools and Instruments - Category 1 (<$150,000)

This research tools and instrumentations grant application aims at the extension of an existing facility for the fabrication of printed microwave circuits, antennas and wave processing surfaces. The proposed additions will enable the fabrication of large printed planar structures - up to 40 cm x 50 cm in size - with very good resolution, in order to fulfill the needs for accurately printed lines and slots in the microwave and lower millimeter wave ranges. One of the key elements in the requested equipment set is a computer controlled drilling and milling machine, on which the mechanical drilling head can be replaced by a UV laser head capable of drawing directly the pattern to be printed on the photosensitive film. This film can then be processed by standard chemical etching. There are several advantages in using such laser drawing/chemical etching process over the conventional mechanical milling process. The most important is the reduced substrate roughness which is a significant factor in the performance of the printed devices. Another advantage is the possibility to process the very thin flexible substrates, such as those used in spacecraft antenna applications. Finally, the optical direct imaging leads to more accurate circuits because it is not affected by tool wear that is occurring during the milling of large surfaces.This equipment will be used by the applicants and a large community of users to fabricate prototypes of surfaces that can spatially modulate the phase, the polarization of incident wave fronts, filter certain frequencies or polarizations, etc. Typically, these surfaces are used in reflectarray and transmitarray (lens) antennas, dichroic reflector surfaces and metasurfaces. The equipment can also be used to implement complex systems on a single large printed surface. A typical example would be a complete transceiver system including active circuits, a beamforming network and antenna elements.