Filter device, antenna apparatus, and antenna module
AssigneeMurata Manufacturing Co., Ltd.
InventorShinya Tachibana
Life of this patent
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Abstract
A filter device includes a first LC series resonator to resonate in series at a first series resonant frequency with a first inductor and a first capacitor, and a second LC series resonator to resonate in series at a second series resonant frequency with a second inductor and a second capacitor. The first and second LC series resonators are connected in parallel and resonate in parallel at a parallel resonant frequency. The second series resonant frequency is lower than the first series resonant frequency. The parallel resonant frequency is between the first and second series resonant frequencies.
Claims20
A filter device comprising:
- a first series resonator to resonate in series at a first resonant frequency with a first inductor and a first capacitor connected in series to the first inductor;
- and
- a second series resonator to resonate in series at a second resonant frequency with a second inductor and a second capacitor connected in series to the second inductor;
- wherein
- the first series resonator and the second series resonator are connected in parallel to each other and resonate in parallel at a third resonant frequency;
- the second resonant frequency is lower than the first resonant frequency;
- and
- the third resonant frequency is between the first resonant frequency and the second resonant frequency.
An antenna module comprising:
- a first antenna apparatus;
- and
- a second antenna apparatus;
- the first antenna apparatus including:
- a first feed circuit to receive/output a radio frequency signal;
- a first antenna to radiate a first resonant frequency and a second resonant frequency as resonant frequencies;
- and
- a filter device between the first feed circuit and the first antenna;
- the filter device having a passband in a first frequency band, a passband in a second frequency band lower than the first frequency band, and an attenuation band in a third band between the first frequency band and the second frequency band;
- the filter device including:
- a first series resonator to resonate in series at the first resonant frequency in the first frequency band with a first inductor and a first capacitor connected in series to the first inductor;
- and
- a second series resonator to resonate in series at the second resonant frequency in the second frequency band with a second inductor and a second capacitor connected in series to the second inductor;
- the first series resonator and the second series resonator being connected in parallel and resonating in parallel at a third resonant frequency in the third frequency band;
- the second antenna apparatus including:
- a second feed circuit to receive/output a radio frequency signal;
- and
- a second antenna to radiate the third resonant frequency as a resonant frequency;
- the first antenna apparatus and the second antenna apparatus being adjacent to or in a vicinity of each other.
Dependencies are inferred from the claim text.