Antenna duplexer
AssigneeMurata Manufacturing Co., Ltd.
InventorMasayuki Atokawa
Life of this patent
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Abstract
A transmitting circuit 25 is provided with a frequency variable bandwidth blocking filter circuit 27 and a phase shifter 29. A series circuit of variable bandwidth capacitors C3, C4 and PIN diodes D1, D2 is electrically connected in parallel to resonators 2,3 of the frequency variable bandwidth blocking filter circuit 27. The transmitting circuit 25 can have two different passing bands by grounding or opening the variable bandwidth capacitors C3,C4 by controlling the voltage to be applied to an electric control terminal CONT1. A receiving circuit 26 is provided with a frequency variable trap circuit 28, the phase shifter 29, and a surface acoustic wave filter circuit 30. The surface acoustic wave filter circuit 30 comprises two surface acoustic wave filter elements 11,12 whose passing band is different from each other.
Claims5
An antenna duplexer, comprising:
- a transmitting terminal;
- a receiving terminal;
- an antenna terminal;
- a transmitting circuit electrically connected between said transmitting terminal and said antenna terminal, said transmitting circuit comprising at least one first resonator and a first element electrically connected to said first resonator and electrically changing a capacitance thereof by a control voltage, said first element switching at least two different passing bands of the transmitting circuit by the control voltage;
- and
- a receiving circuit electrically connected between said receiving terminal and said antenna terminal, said receiving circuit comprising at least one second resonator, a second element electrically connected to said second resonator and electrically changing a capacitance thereof by a control voltage, said second element switching at least two different passing bands of the receiving circuit by the control voltage, and at least one surface acoustic wave filter element coupled thereto.
Dependencies are inferred from the claim text.