I understand that certain antenna designs (particularly phased arrays) require feeding each radiating element with a certain number of degrees of phase separation in order to achieve a desired radiation pattern or beamwidth.
I found this 2-meter phased array [pdf] article which goes fairly in-depth into the design and theory but glances over the exact details involved in computing the coax lengths for the phasing harness:
The antenna design in the article proposes using a T-connector with a 22" length of coax going to one antenna and a 16" length of coax going to the other antenna to (supposedly) achieve 135-degrees of phase separation.
So my question is... is there a general method or formula for computing these phasing line lengths? (Are the values shown in the article even correct?)