GB1450118A - Hybrid structures - Google Patents

Abstract

1450118 Hybrid-T structures THOMSONCSF 12 Dec 1973 [12 Dec 1972] 57637/73 Heading H1W Hybrid-T structures, having the same properties as those normally provided by known waveguide 4-port junctions, are formed on a ceramic substrate from symmetric and asymmetric transmissions lines forming shunt and series T-junctions. In particular, a symmetric or asymmetric line forms the common arms of two T-junctions whose stems are formed by lines of opposite kinds, whereby one T-junction is a series junction and the other a shunt junction. Thus, the upper, metallized surface of ceramic substrate 6, Fig. 5, is formed with a slotted (asymmetric) line 140 forming, on the one hand, a series junction with slotted (asymmetric) line 14 and, on the other hand, a shunt junction with the microstrip (symmetric) line 5. The latter is printed on the lower surface of the substrate 6 and overlaps the junction by a quarter wavelength at the mid-band frequency. Ports 1, 4 are mutually decoupled, an input at port 1 provides phase-opposed outputs at ports 2, 3 and an input at port 5 provides co-phasal outputs at ports 2, 3, when the ports are properly terminated. In the modification of Fig. 6, a slotted line 21 forms a series junction with slotted line 20 and a shunt junction with coplanar line 10, 11. The latter consists of an elongated planar conductor 11 arranged on the central axis of a non-conductive slot 10; it is electrically symmetrical. In a modification (Fig. 7, not shown), ports 2, 3 are provided by a microstrip line, port 1 by a further microstrip line, and port 4 by a slotted line. In a further modification (Fig. 8, not shown), ports 2, 3 are provided by a co-planar line, port 1 by a further co-planar line, and port 4 by a slotted line.