Planar printed circuit antenna

Abstract

A planar printed circuit antenna ( ) comprises a printed circuit board (PCB) ( ) mounted on an insulative substrate ( ), a plurality of electronic dipole units ( ) and a coaxial feeder element ( ). The PCB comprises an upper layer ( ), and a lower layer ( ) opposite the upper layer and fixed on the insulative substrate. The coaxial feeder element includes an RF cable ( ), and a neck ( ) securely attached around the RF cable for engaging the coaxial feeder element with the substrate. The RF cable has a conducting core wire ( ) connected to the upper layer via a jumper wire ( ), and an outer conductor ( ) around the conducting core wire directly connected to the lower layer. The electronic dipole units are respectively arranged on the upper and lower layers of the PCB, and are respectively coupled to the conducting core wire and the outer conductor. The PCB has space available for accommodating the jumper wire of varying length. The jumper wire has an insulative coating. In cooperation with the available space of the PCB the jumper wire is adapted to be easily substituted by the other jumper wire having different length, thereby changing an effective frequency band of the antenna.