Patent ID: 9705170
Date: 2017-07-11
CPC Classifications: H01P,H03H

Claim:
1. A switchable band-pass filter for narrow band filtering over a large frequency band in a co-site filter application, said switchable band-pass filter comprising: a first filter element and a second filter element, which are directly coupled to one another via a switchable coupling device, wherein the first filter element includes a first connection and the second filter element includes a second connection, wherein the first connection is at least one of a band-pass filter input and a band-pass filter output and the second connection is at least a respective other one of the band-pass filter output and the band-pass filter input, wherein the first and the second filter elements each provide a conductor structure formed in a flat plane, which includes respectively at least two line portions, the first and the second filter elements being in direct electromagnetic interaction with one another in at least a part of the at least two line portions extending in a straight line, wherein the first and the second filter elements are microstrip lines and each is arranged on a different layer of at least one printed circuit board, wherein the at least two line portions of the first and the second filter elements are arranged parallel to one another, such that each line portion of the at least two line portions of the first filter element alternates with each line portion of the at least two line portions of the second filter element, wherein the at least two line portions of the first and the second filter elements respectively are each connected at one end in an electrically conductive manner, and wherein each of the line portions of the first and the second filter elements is connected at another end with a short circuit to earth and the short circuits are disposed on a straight line which is perpendicular to the line portions.