Band-pass filter circuit
First Claim
1. A band pass filter circuit, wherein said band pass filter passes a passband which is a frequency band between a first cutoff frequency and a second cutoff frequency with respect to an input frequency of an inputted input signal, said band pass filter circuit comprising:
- a first resonant circuit configured to be connected to a signal line in series and set a first resonant frequency as said first cutoff frequency;
a second resonant circuit configured to be connected to said signal line in series and set a second resonant frequency as said second cutoff frequency;
a third resonant circuit configured to be connected to said signal line in parallel at a connection node where said first resonant circuit and said second resonant circuit are connected, and set a third resonant frequency as a band-pass center frequency between said first cutoff frequency and said second cutoff frequency; and
at least one of a capacitive circuit configured to be installed between said first resonant circuit and said connection node and an inductive circuit configured to be installed between said second resonant circuit and said connection node.
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Accused Products
Abstract
A band pass filter circuit, wherein the band pass filter passes a frequency band between a first cutoff frequency and a second cutoff frequency with respect to an input frequency of an input signal, the band pass filter circuit includes: a first resonant circuit; a second resonant circuit; a third resonant circuit; at least one of a capacitive circuit and an inductive circuit. The first resonant circuit is connected to a signal line in series and sets a first resonant frequency as the first cutoff frequency. The second resonant circuit is connected to the signal line in series and sets a second resonant frequency as the second cutoff frequency. The third resonant circuit is connected to the signal line in parallel at a node where the first and second resonant circuits are connected, and sets a third resonant frequency as a band-pass center frequency between the first and second cutoff frequencies.
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Citations
17 Claims
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1. A band pass filter circuit, wherein said band pass filter passes a passband which is a frequency band between a first cutoff frequency and a second cutoff frequency with respect to an input frequency of an inputted input signal, said band pass filter circuit comprising:
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a first resonant circuit configured to be connected to a signal line in series and set a first resonant frequency as said first cutoff frequency; a second resonant circuit configured to be connected to said signal line in series and set a second resonant frequency as said second cutoff frequency; a third resonant circuit configured to be connected to said signal line in parallel at a connection node where said first resonant circuit and said second resonant circuit are connected, and set a third resonant frequency as a band-pass center frequency between said first cutoff frequency and said second cutoff frequency; and at least one of a capacitive circuit configured to be installed between said first resonant circuit and said connection node and an inductive circuit configured to be installed between said second resonant circuit and said connection node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A communication device comprising:
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a communication unit configured to includes; a band pass filter circuit configured to pass a passband which is a frequency band between a first cutoff frequency and a second cutoff frequency with respect to an input frequency of an inputted input signal, and include; a first resonant circuit configured to be connected to a signal line in series and set a first resonant frequency as said first cutoff frequency, a second resonant circuit configured to be connected to said signal line in series and set a second resonant frequency as said second cutoff frequency, a third resonant circuit configured to be connected to said signal line in parallel at a connection node where said first resonant circuit and said second resonant circuit are connected, and set a third resonant frequency as a band-pass center frequency between said first cutoff frequency and said second cutoff frequency, and at least one of a capacitive circuit configured to be installed between said first resonant circuit and said connection node and an inductive circuit configured to be installed between said second resonant circuit and said connection node, and an antenna, wherein said communication unit modulates a transmission data, converts into a transmission wireless signal and sends said transmission wireless signal from said antenna; and a control unit configured to output said transmission data to said communication unit, wherein said antenna receives a reception wireless signal as said input signal, said band pass filter circuit passes said passband with respect to said input frequency corresponding to said reception wireless signal, and said communication unit demodulates said reception wireless signal, converts into a reception data and outputs to said control unit. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification