A balun comprises a one-to-two, equal-power, matched power divider having branch transmission lines whose lengths differ by 1/2 wavelength at a design frequency. The shorter of these two branch transmission lines has two 1/4 wavelength long, shorted stub transmission lines branching therefrom 1/4 wavelength...http://www.google.es/patents/US4725792?utm_source=gb-gplus-sharePatente US4725792 - Wideband balun realized by equal-power divider and short circuit stubs
Wideband balun realized by equal-power divider and short circuit stubs
