On an Ultrabroad -Band Hybrid Tee

A hybrid tee is investigated which consists of two broad-band line transformers and a lumped branching point. The branching point forms a bridge circuit, the resistances of which are determined by six lines and their load resistors. The bandwidth is wider than three decades, extending from 2.4 MHz to 5 GHz, and is determined by the transformers. In a special version, the upper cutoff frequency can be shifted to about 12 GHz. The isolation between opposite lines is greater than 40 dB.