A Wide-Band Strip-Line Balun

A new wide-band strip-line balun that uses a pair of dual coupled-strip-line band-pass filters is described. It can operate over bandwidths up to about 8:1 in the frequency range of about 100 to 10,000 mc. Design data and theoretical performance curves for typical wide-band baluns of this type are presented. The measured performance of an experimental balun operating over a 3:1 frequency range centered at 3000 mc is compared with the theoretical performance, and the effects of discontinuities and dissymmetries in the experimental balun are discussed.