Patent ID: 8315577
Filing Date: 2012-11-20
Classification: H04B

Abstract:
1. A multiband high-frequency circuit used between an antenna capable of conducting transmission and reception in at least three communications systems, and transmitting and receiving circuits of at least three communications systems, comprising: a high-frequency switch circuit which switches the three-way connection of said antenna to a first path, to a second path, and to a third path, a first diplexer circuit disposed in said first path, and a second diplexer circuit disposed in said second path; each of said first and second diplexer circuits comprising a lower-frequency-side filter circuit and a higher-frequency-side filter circuit; a path connected to the lower-frequency-side filter circuit of said first diplexer circuit being provided with a bandpass filter circuit, and said third path being provided with a bandpass filter circuit; the bandpass filter circuit in a path connected to the lower-frequency-side filter circuit of said first diplexer circuit being connected to a receiving circuit of the first communications system; a path connected to the higher-frequency-side filter circuit of said first diplexer circuit being connected to a receiving circuit of the second communications system; a path connected to the lower-frequency-side filter circuit of said second diplexer circuit being connected to a transmitting circuit of the first communications system; a path connected to the higher-frequency-side filter circuit of said second diplexer circuit being connected to a transmitting circuit of the second communications system; and the bandpass filter circuit in said third path being connected to a transmitting and receiving circuit of the third communications system, wherein said high-frequency switch circuit comprises a first high-frequency switch circuit which switches the connection of said antenna to said second path and to a common path of said first path and said third path, and a second high-frequency switch circuit which switches the connection of said common path to said first path and to said third path.