Compact microwave/millimeter wave filter and method of manufacturing and designing thereof

摘要

A filter has suspended metal structures which are surrounded by a metal shield on all sides, except at the input and output ports. The shape of the metal determines the type of filter. The signal can be coupled into and out of the filter either by coplanar waveguide ports, stripline ports, or through a waveguide connection. The metals making up the filters are suspended, and only come into contact with air or with an extremely thin dielectric. This minimizes both dielectric losses and ohmic losses in the metal, and allows filters to be made without separately mounted dielectric resonators. The low losses allows, in the cause of a bandpass filter, high Q resonators to be achieved, thus providing a high quality filter with low insertion loss in the passband.