Patent ID: 6864743
Filing Date: 2005-03-08
Classification: H03F

Abstract:
1. A device for amplifying communication signals in a predetermined microwave frequency band above 500 MHz, comprising a printed circuit board, PCB, with transmission line segments arranged between an input port and an output port, an amplifier unit with at least one low noise amplifier, LNA, a bypass segment extending in parallel to said amplifier unit, and switching elements for activating said bypass segment in a bypass mode of the device, in case said amplifier unit becomes inoperable, and for effectively blocking the bypass segment in an active mode of the device, said bypass segment comprising a series of at least two segment sections having at least one junction point connected to an associated one of said switching elements, characterized in that said bypass segment comprises at least one section of coupled transmission lines disposed adjacent to each other so as to provide a strong electromagnetic coupling therebetween, whereby the isolation against feedback through the bypass segment is improved.