Two:stage bandpass filter with circular waveguide resonator - has angle between coupling points minimum of 5 degrees different from right angle

摘要

A H 111 2-stage bandpass filter has a point of attenuation above and below the passband. It is suitable for passing the very short waves and consists of a Hill circular waveguide resonator. The orthogonal modes are coupled by thread shaped coupling bolts. There are two coupling points for feeding and picking off electromagnetic energy. The angles between the coupling points (1, 2) are at least 5 degrees different from a right angle. The coupling bolts (3) in the region between the coupling points is at an angle of 45 degrees to anyone of the coupling points. The distance between the point of attenuation from the mid frequency of the passband is only a few parts in a thousand.