Patent attributes
A dielectrically-loaded helical antenna has a ceramic cylindrical core and, formed on the cylindrical surface of the core, a plurality of conductive helical antenna elements. The antenna elements are coupled to a pair of feed connection conductors generally centrally located on an end surface of the core, the coupling between the antenna elements and the feed connection conductors being by way of a matching section comprising a laminate board having at least three conductive layers and insulative layers between the conductive layers arranged in an alternating manner. Each conductive layer has a first portion forming part of a respective shunt capacitance, the conductive layers and the insulative layers together acting to form a plurality of capacitors shunt-connected across the antenna elements. One of the conductive layers includes a second portion forming a series inductance between one of the feed connection conductors and at least one of the antenna elements.