A reactance filter can be use branching technology. A series circuit contains a first filter element, a second filter element and a third filter element. Each filter element includes a first impedance element that is connected in series with an impedance element of an adjacent element. Each filter element also includes a second element connected to the first impedance element of that filter. The first and/or second impedance element of each filter element comprises a includes a resonator. Each impedance element has a bandwidth that is expressed by its pole zero distance and each filter element comprises a means for setting the bandwidths of the impedance elements.