Step 1: Harebrained idea
I thought if one director was good, maybe more would be better. So I used the dimensions from the patch antenna to determine an aperture for a conical wave-guide, this so that I could use my fire-extinguisher based cantenna as a wave-guide feed. The patch directions recommend going to a store like a dollar store for a lid. I happened to find some cutting boards that were just big enough and bought one to test in the microwave. Passing that test, I purchased more and decided to use 3/4" pvc tubing as a frame.
This is the page where you can find the latest version of the waveguide calculator, which I used to find the right length for this cone, based on the diameter of my existing cantenna waveguide, and on the 242mm diameter directors. This software indicated a possible gain of 13 Db. If it came close to that is still unknown as I still need to learn how to measure that. This is also where I can learn how to measure my results, if I would just spend more time there!
Seeing as I'm throwing in software links - Delta Cad is what I use to draw my designs. However, I took several years of drafting classes and what little of that I can still remember is not included in the help section that comes with Delta Cad, sorry.