Patent ID: 8843098
Filing Date: 2014-09-23
Classification: H03F,H03H

Abstract:
1. A filter, comprising: first and second input nodes for receiving balanced signals; an inductive-capacitive (LC) circuit coupled between the first and second input nodes and first and second intermediate nodes, wherein the LC circuit comprises a first shunt LC resonator coupled between the first and second input nodes, a second shunt LC resonator coupled between the first and second intermediate nodes, and a plurality of capacitors and inductors between the first and second shunt LC resonators; and a coupling circuit that couples the first and second intermediate nodes to an output node, wherein balanced signals within a filter bandwidth are transmitted from the first and second input nodes to the output node and balanced radiofrequency signals outside the filter bandwidth are substantially shorted to ground; wherein the coupling circuit comprises at least one of shunt or series inductors and a coupling element between the output node and an effective ground; and wherein said at least one of the plurality of shunt inductors and said at least one coupling element are formed using metal traces that are separated from each other by a selected distance.