Radio frequency energy launcher

Abstract

A radio frequency energy launcher providing efficient energy transfer between a coaxial transmission line having spaced inner and outer conductors and a microstrip transmission line comprising a first relatively thin strip conductor and second wider ground plane conductor separated by a dielectric substrate. The launcher includes a conductive housing providing a passageway forming an outer conductor and a spaced inner conductor angled with respect to the passageway outer conductor forming wall and a surface of the substrate. Such angled inner conductor having an end region connected to the coaxial transmission line and having the other end interconnected to the thin strip conductor of the microstrip transmission line. The inner conductor is angled acutely and/or obliquely to such housing wall and a surface of dielectric substrate. The launcher structure is mounted on an extension of the wider ground plane conductor of the microstrip transmission line thus permitting the utilization of a substantially thinner ground plane conductor member while assuring firm mechanical contact with the thin strip conductor microstrip transmission line. The angularly orientated launcher provides for maintaining constant impedance in the transformation of electromagnetic energy fields from a concentric coaxial line distribution to a concentrated eccentric configuration for microstrip line transmission.