Broad-band lumped-element 180-degree hybrids

摘要

A size reduction of passive devices is a key technology for a large-scale and cost-effective MMICs. From this point of view, the present paper treats 180-degree lumped-element hybrids systematically and analytically. We show various concrete circuit-constructions consisting of a phase inverter or symmetrical lattice networks, and their frequency properties. As a result, several interesting circuit structures arc suggested, i.e., a 180-degree hybrid with a phase inverter possesses about one octave bandwidth and the bandwidth ratio of a 180-degree hybrid constructed of lattice networks reaches 1.76 octaves. Next the validity of the design technique is demonstrated by an electromagnetic simulator (Sonnet). Finally we calculate the frequency characteristics of some 180-degree hybrids with regard to the conductor loss of those hybrids.