A Wide-Band Balun

Experimental results are given for a transformer from an unbalanced 50-ohm coaxial line to a balanced pair of 50-ohm coaxial lines. The design is one proposed by Marchand. The balance, standing wave ratio, and insertion loss are nearly constant over a 13 to 1 frequency range from 650 mc to 8500 mc. The standing wave ratio is less than 2.1 to one and the insertion loss is about 0.5 db over this band of frequencies.