68 are connected to the balanced output ports 31 33 fig3 respectively the benefits of using the above described printed circuit as opposed to the twisted twin leads of the prior art are twofold for one the uniformity of the transmission lines is closely controllable and for another printed transmission lines can be made physically smaller than twin leads and can be fabricated easily at relatively low cost because of its size and uniformity the printed circuit approach of this invention allows the guanella balun concept to be extended from the previously possible less than 100 mhz range into microwave frequencies up to the 10 ghz range specifically as shown in fig6 a and 6b the voltage standing wave ratio vswr at the 50 u03c9 input of a prototype embodiment of the invention was measured at no more than 1 5 1 up to about 4 ghz and remained below 2 1 all the way to about 10 ghz fig7 shows that the prototype of fig6 a and b also has excellent amplitude tracking properties with about a 1 db loss at 1 ghz and about a 2 db loss at 2 ghz the amplitudes of each output were within 1 db of each other over all of that range likewise as shown in fig8 the relative phase difference between the two outputs was 180 u00b0 u00b1 4 u00b0 over the entire 0 3 ghz to 2 5 ghz range thus the prototype balun of this invention demonstrated a usable frequency range of at least vhf through l band frequencies the small size of the inventive balun the prototype described herein was about 6 6 cm u00d7 0 75 cm u00d7 2 3 cm the largest dimension being much.