US 4413242 A abstract an improved magic tee constructed to maximize the power that can be transferred from the h plane arm to the collinear side arms and vice versa the matching post is designed to maximize the breakdown voltage between the post tip and the walls of the e plane arm this is accomplished by selecting the post diameter to produce a ratio of the e plane arm height to post diameter which develops a characteristic impedance corresponding to that of a coaxial transmission line constructed to withstand the maximum breakdown voltage between the transmission line center conductor and conductive shielding for a given shield separation application_number US 29822581 A description referring to the drawings fig1 shows a waveguide magic tee which is comprised of four waveguide segments producing a four port device each waveguide segment has a height h a width w and a length l the h plane arm 2 forms a first waveguide section attached to two collinear side arms 6 and 8 the e plane arm 4 forms the fourth waveguide section of the magic tee in the illustrated embodiment of the invention the e plane arm is shown with a step 14 such steps are used to adapt the section output to the input of a waveguide section to which the tee may be connected for example the magic tee may be constructed of waveguide sections having a height of 0 670 inches and width of 2 840 if the e plane arm has to be coupled to.