Patent ID: 6674340
Filing Date: 2004-01-06
Classification: H01P,H01Q

Abstract:
A switched loop RF radiator circuit, comprising:a radiator element; a circuit RF input/output (I/O) port; a balun coupled between the radiator element and the I/O port, the balun including a 180Â° switched loop circuit having first and second transmission line legs coupled to a balun transition to provide a selectable 180Â° phase shift, and a microelectromechanically machined (MEM) switch circuit to select one of said transmission line legs, wherein said switch circuit includes first and second single-pole-single-throw (SPST) MEM switch circuits; wherein a first pole of said first MEM switch circuit is connected to a first transmission line, a second pole of said first MEM switch circuit is connected to the first transmission line leg, a first pole of said second MEM switch is connected to a second transmission line, and a second pole of the second MEM switch circuit is connected to the second transmission line leg, the first and second transmission lines connected together at a junction and coupled to the I/O port; wherein in a first circuit phase state, the first MEM switch is set to a closed state, and the second MEM switch is set to an open state, and in a second phase state mode the first MEM switch is set to an open state and the second MEM switch is set to a closed state to provide a 180Â° phase difference from the first phase state; and wherein in a reflective state, the first and second MEM switches are both set to the closed state to reflect incident RF energy.