Ozen Engineering co-authored with Averatek Corporation this technical paper on patch antenna structures within printed circuit boards with embedded air dielectrics for improved efficiency and directivity.
For this work, we selected two target carrier frequencies: (i) 2.4 GHz (Bluetooth and WiFi) and (ii) 5.5 GHz (WiFi). At each frequency we designed three models, for six total antennas. At a given frequency, one antenna was a baseline model with a PCB laminate dielectric between the patch and the ground plane, the same laminate used for overall construction.
For the two experimental antennas at a given frequency, we replaced the dielectric with an air pocket in the shape of a rectangular parallelepiped (box). We began with the constraint that the height of a cavity would be the same as the dielectric that it replaced in the baseline unit. Keeping the internal height as a constant, we arrived at patches and overall antenna lateral dimensions that targeted the two carrier frequencies. The difference between the two experimental antennas at a given frequency was this: for one of those antennas, the air cavity was the same lateral size as the patch, and for the other model the air cavity was larger in extent than the patch, roughly 18 – 40% greater in a particular direction.