Patent ID: 7564321
Filing Date: 2009-07-21
Classification: H01Q,H03H

Abstract:
1. A dual-frequency matching circuit comprising: first and second input terminals that receive a first RF signal with a frequency of 0.88 GHz and a second RF signal with a frequency of 1.86 GHz, respectively, from an RF circuit with an impedance of 50 Ω; first and second output terminals that are connected to an antenna; and a group of circuit elements that are connected between the input terminals and the output terminals, wherein the group of circuit elements includes first, second, third and fourth elements, and wherein the first and fourth elements are connected in series between the first and second input terminals and the second input terminal is short-circuited with the second output terminal, and wherein the second element is connected between the first input terminal and the first output terminal, and wherein the third element is connected between a connection node of the first and fourth elements and the first output terminal, and wherein the group of circuit elements is one of the four sets consisting of first, second, third and fourth ones, where the first set includes an inductor with an inductance of 5.168 nH, an inductor with an inductance of 3.633 nH, a capacitor with a capacitance of 1.779 pF, and a capacitor with a capacitance of 1.207 pF as the first, second, third and fourth elements, respectively, the second set includes an inductor with an inductance of 1.951 nH, a capacitor with a capacitance of 7.335 pF, a capacitor with a capacitance of 14.190 pF, and an inductor with an inductance of 15.834 nH as the first, second, third and fourth elements, respectively, the third set includes an inductor with an inductance of 15.059 nH, a capacitor with a capacitance of 1.286 pF, an inductor with an inductance of 12.071 nH, and a capacitor with a capacitance of 5.602 pF as the first, second, third and fourth elements, respectively, and the fourth set includes an inductor with an inductance of 4.355 nH, a capacitor with a capacitance of 1.005 pF, an inductor with an inductance of 6.195 nH, and a capacitor with a capacitance of 5.308 pF as the first, second, third and fourth elements, respectively.