Dielectric filter for duplexer in communications device has dielectric block with through holes for conductors extending from one end to the other with stepped rectangular cross-section

摘要

The dielectric filter has a dielectric block with a parallelepiped shape, through holes (2a, 2b) in the block extending from one end to the other, internal conductors in the holes and a conductor (4) on the outer surface of the block with one end open and the other acting as a short circuit, so that a number of dielectric resonators are formed. The holes are rectangular in cross-section with a depth between 10 and 50 per cent of their length forming a step. Independent claims are also included for a duplexer with a number of dielectric filters and for a communications arrangement.