Quasi-ideal multilayer two- and three-strip directional couplers for monolithic and hybrid MICs

Abstract

In this paper, the properties of multilayer two-and three-strip asymmetric coupled lines are described using their coupled-mode parameters. Examples of quasi-ideal, microstrip, and coplanar directional couplers designed in monolithic and hybrid microwave integrated-circuit technology, consisting of various layered structures of bilevel and trilevel coupled lines, are presented together with experimental results for two 3-dB couplers on ceramic-filled polytetrafluoroethylen and polyimide laminates.

Investigations into lightweight patch element for use in dual- or multi- polarized antenna arrays

“…Calculated isolations between ports are typically not worse than 30 dB ( Figure 3). The investigated patches uses minute directional couplers printed on a membrane substrate [3]. To ensure convenient measurements of subtle distributions of axial ratio within the main beam we used models in the S-band.…”

Ka-band surface-mount directional coupler fabricated using micro-rectangular coaxial transmission lines

“…A comprehensive study of both symmetric and asymmetric multilayer directional couplers at frequencies below 8GHz is given in [1].…”

Wideband multilayer directional coupler with tight coupling and high directivity

“…One group of such circuits consists of microstrip directional couplers with distributed coupling [1], which have gained significant interest in the literature for decades [2–17], even recently [18–21]. In this article, we consider microstrip structures, which are planar structures with a solid ground plane on the bottom face, are open on the top, have one or several dielectric layers whose permittivities may be different, and have strips, placed parallel to the ground, in any layer.…”