Patent ID: 8648666
Filing Date: 2014-02-11
Classification: H01P,H03H

Abstract:
1. A multimode frontend circuit comprising first, second and third ports, a first transmission path between the first and second ports, and a second transmission path between the first and third ports, each of the transmission paths comprising: two input/output lines; a first transmission line having one end connected to one of the input/output lines and the other end connected to the other input/output line; a second transmission line having one end connected to the one of the input/output lines and the other end connected to the other input/output line; and one or a plurality of termination switch circuits; wherein: the electrical length of the first transmission line is equal to the electrical length of the second transmission line; a characteristic impedance for an even mode and a characteristic impedance for an odd mode of the first transmission line are constant along the length of the first transmission line; a characteristic impedance for an even mode and a characteristic impedance for an odd mode of the second transmission line are constant along the length of the second transmission line; the characteristic impedance for the even mode of the first transmission line is equal to the characteristic impedance for the even mode of the second transmission line; the characteristic impedance for the odd mode of the first transmission line is equal to the characteristic impedance for the odd mode of the second transmission line; and