Microwave filter having means for capacitive interstage coupling between transmission lines

摘要

A microwave filter comprising within a conductive casing, a plurality of resonant transmission lines (10-12) arranged parallel between opposed end walls (23, 24) of the casing, a plurality of shielding members (16,17) each located between adjacent transmission lines, and a capacitive interstage coupling member disposed transverse to the transmission line. The interstage coupling member comprises a dielectric member (30) and a plurality of conductive regions (31-33) arranged successively thereon so as to establish capacitive coupling between adjacent conductive regions. Each transmission line is connected at one end to a side wall (21) of the casing and supported at the other end by the dielectric member (30) in electrical contact with a respective one of the conductive regions (31-33), whereby the interstage coupling between the transmission lines is provided by the capacitively coupled conductive regions.