Calibration and Performance of Two New Ultra-Wideband Four-Port-Based Systems

This paper presents two new structures for four-port-based systems with ultrawide operating bandwidth, using a combination of power dividers and delay lines. The prototype circuits, initially conceived to operate in the frequency band from 1 to 4 GHz, are fabricated to validate these new architectures by means of a hybrid integrated-circuit technology. Associated with these systems, a new explicit calibration solution is developed to extend the frequency band of use up to 10 GHz. Comparison between the results obtained from the new structures with those given by a conventional network analyzer show the validity of the systems proposed.