Radio-frequency filter device and communication apparatus
AssigneeMurata Manufacturing Co., Ltd.
InventorKoji Nosaka
Life of this patent
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Abstract
A filter module (20) includes a filter circuit (22) that includes switches (221SW and 224SW), a pass band of the filter circuit (22) being switched in accordance with switching between ON and OFF of the switches (221SW and 224SW); and an impedance matching circuit (21) that is disposed in at least one of a preceding stage and a subsequent stage of the filter circuit (22) and that includes a switch (212SW), an element value for achieving impedance matching being switched in the impedance matching circuit (21) in accordance with switching between ON and OFF of the switch (212SW). The switches (221SW and 224SW) and the switch (212SW) synchronize with each other regarding timing of switching between ON and OFF.
Claims15
A radio-frequency filter device comprising:
- a radio-frequency filter circuit comprising a first switch configured to selectively switch frequencies of a pass band or a frequency of at least one attenuation pole of the radio-frequency filter circuit in accordance with a state of the first switch;
- and
- an impedance matching circuit comprising a second switch configured to selectively adjust an impedance value for achieving impedance matching with the impedance matching circuit in accordance with a state of the second switch, wherein
- the states of the first switch and the second switch are selectively switched in synchronization with each other.
Dependencies are inferred from the claim text.