Patent ID: 7307494
Filing Date: 2007-12-11
Classification: H04B

Abstract:
1. A signal separating device comprising: a first and a second circuit branch connected to an antenna port, the first circuit branch comprising a filter for passing signals in a first frequency band, and the second circuit branch comprising a filter for passing signals in a second frequency band, wherein, in the second frequency band, the first circuit branch provides a first capacitive impedance between the antenna port and electrical ground, and in the first frequency band, the second circuit branch provides a second capacitive impedance between the antenna port and electrical ground, and wherein the device further comprises an impedance matching circuit provided at the antenna port and provides, in the second frequency band, a first inductive impedance between the antenna port and ground which substantially cancels out the first capacitive impedance, and provides, in the first frequency band, a second inductive impedance between the antenna port and ground which substantially cancels out the second capacitive impedance.