MULTI-STAGE AMPLIFIER
In a multi-stage amplifier, a plurality of amplifier circuits are connected in series, and the amplifier circuit has a 0 dB frequency at which magnitude of a normalized transfer function normalized at a low frequency gain becomes 1 at a frequency other than a direct current.
1 - 8 . (canceled)
9 . A multi-stage amplifier, comprising:
a plurality of amplifier circuits connected in series, each of the plurality of amplifier circuits having a 0 dB frequency at which magnitude of a normalized transfer function normalized at a low frequency gain becomes 1 at a frequency other than a direct current.
10 . The multi-stage amplifier according to claim 9 , wherein when a configuration of each of the plurality of amplifier circuits is expressed with a circuit model, each of the plurality of amplifier circuits includes:
an input capacitance connected between a signal input terminal and ground;
an amplifier configured to amplify a signal input to the signal input terminal;
an output resistor having a first end connected to an output terminal of the amplifier;
an output capacitance connected between a second end of the output resistor and ground; and
an inductor having a first end connected to a second end of the output resistor and having a second end connected to a signal output terminal.
11 . The multi-stage amplifier according to claim 10 , wherein:
when the output resistor is represented by R o , the output capacitance is represented by C o , the inductor is represented by L, an input capacitance of another one of the plurality of the amplifier circuits in a following stage connected to one of the plurality of amplifier circuits in each stage of the multi-stage amplifier is represented by C nx , Q=(L/C nx ) 1/2 /R o , and k c =C o /C nx , and ranges of Q and k c are expressed by:
max
(
7
3
2
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1
-
2
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2
7
2
8
)
4
+
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6
7
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k
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.
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)
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,
4
k
c
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k
c
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.
5
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1
2
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k
c
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k
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.
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3
8
.
12 . The multi-stage amplifier according to claim 11 , wherein when the 0 dB frequencies of each of the plurality of amplifier circuits is different, an average of the 0 dB frequencies of the plurality of amplifier circuits is F1.
13 . The multi-stage amplifier according to claim 11 , wherein when a resonance sharpness of each of the plurality of amplifier circuits is different, an average of the resonance sharpness of the plurality of amplifier circuits is Q.
14 . The multi-stage amplifier according to claim 9 , wherein:
when a configuration of the amplifier circuit in each stage is expressed with a circuit model, the amplifier circuit in each stage includes a first amplifier circuit and a second amplifier circuit connected at a stage subsequent to the first amplifier circuit,
wherein the first amplifier circuit includes:
a first input capacitance connected between a signal input terminal and a ground;
a first amplifier configured to amplify a signal input to the signal input terminal;
a first output resistor having a first end connected to an output terminal of the first amplifier;
a first output capacitance connected between a second end of the first output resistor and ground; and
a first inductor having a first end connected to a second end of the first output resistor, and
wherein the second amplifier circuit includes:
a second input capacitance connected between a second end of the first inductor and ground;
a second amplifier configured to amplify a signal input from the first amplifier circuit;
a second output resistor having a first end connected to an output terminal of the second amplifier;
a second inductor having a first end connected to a second end of the second output resistor and having a second end is connected to a signal output terminal; and
a second output capacitance connected between the signal output terminal and the ground.
15 . The multi-stage amplifier according to claim 14 , wherein a lower frequency among the 0 dB frequencies of the first amplifier circuit is equal to the 0 dB frequency of the second amplifier circuit, and a product of an extreme value of the magnitude of the normalized transfer function of the first amplifier circuit at the lower frequency and an extreme value of the magnitude of the normalized transfer function of the second amplifier circuit is 1.
16 . The multi-stage amplifier according to claim 15 , wherein when R o is the first output resistor, C o is the first output capacitance, L is the first inductor, C nx is the second input capacitance, |h(Ωa2)| is an extreme value of a normalized transfer function of the first amplifier circuit at a lower frequency of the 0 dB frequency of the first amplifier circuit, Q=(L/C nx ) 1/2 /R o , and k c =C o /C nx , ranges of Q and k c are expressed by:
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17 . The multi-stage amplifier according to claim 14 , wherein when R o is the first output resistor, C o is the first output capacitance, L is the first inductor, C nx is the second input capacitance, |h(Ωa2)| is an extreme value of a normalized transfer function of the first amplifier circuit at a lower frequency of the 0 dB frequency of the first amplifier circuit, Q=(L/C nx ) 1/2 /R o , and k c =C o /C nx , ranges of Q and k c are expressed by:
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.
18 . A multi-stage amplifier, comprising:
a plurality of amplifier circuits connected in series, each of the plurality of amplifier circuits having a 0 dB frequency at which magnitude of a normalized transfer function normalized at a low frequency gain becomes 1 at a frequency other than a direct current, wherein each of the plurality of amplifier circuits includes:
an amplifier configured to amplify a signal input to a signal input terminal;
an output resistor having a first end connected to an output terminal of the amplifier; and
an inductor having a first end connected to a second end of the output resistor and having a second end connected to a signal output terminal.
19 . The multi-stage amplifier according to claim 18 , wherein:
when the output resistor is represented by R o , an output capacitance of one of the plurality of amplifier circuits in each of the stages is represented by C o , the inductor is represented by L, an input capacitance of another one of the plurality of the amplifier circuits in a following stage connected to the one of the plurality of amplifier circuits in each stage of the multi-stage amplifier is represented by C nx , Q=(L/C nx ) 1/2 /R o , and k c =C o /C nx , and ranges of Q and k c are expressed by:
max
(
7
3
2
{
1
-
2
(
2
7
2
8
)
4
+
1
6
7
(
k
c
-
0
.
5
)
}
,
4
k
c
(
1
-
k
c
)
2
-
1
)
≤
(
Q
-
1
)
≤
0
.
5
-
1
2
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k
c
-
0
.
5
)
2
+
1
2
(
k
c
-
0
.
5
)
3
8
.
20 . The multi-stage amplifier according to claim 19 , wherein
when a resonance sharpness of each of the plurality of amplifier circuits is different, an average of the resonance sharpness of the plurality of amplifier circuits is Q.
21 . A multi-stage amplifier, comprising:
a plurality of amplifier circuits connected in series, each of the plurality of amplifier circuits having a 0 dB frequency at which magnitude of a normalized transfer function normalized at a low frequency gain becomes 1 at a frequency other than a direct current, wherein the amplifier circuit in each stage includes a first amplifier circuit and a second amplifier circuit connected at a stage subsequent to the first amplifier circuit,
wherein the first amplifier circuit includes:
a first amplifier configured to amplify a signal input to a signal input terminal;
a first output resistor having a first end connected to an output terminal of the first amplifier; and a first inductor having a first end connected to a second end of the first output resistor, and
wherein the second amplifier circuit includes:
a second amplifier configured to amplify a signal input from the first amplifier circuit;
a second output resistor having a first end connected to an output terminal of the second amplifier; and
a second inductor having a first end connected to a second end of the second output resistor and having a second end is connected to a signal output terminal.
22 . The multi-stage amplifier according to claim 21 , wherein a lower frequency among the 0 dB frequencies of the first amplifier circuit is equal to the 0 dB frequency of the second amplifier circuit, and a product of an extreme value of the magnitude of the normalized transfer function of the first amplifier circuit at the lower frequency and an extreme value of the magnitude of the normalized transfer function of the second amplifier circuit is 1.
23 . The multi-stage amplifier according to claim 21 , wherein when R o is the first output resistor, C o is a first output capacitance of the first amplifier circuit, L is the first inductor, C nx is a second input capacitance of the second amplifier circuit, |h(Ωa2)| is an extreme value of a normalized transfer function of the first amplifier circuit at a lower frequency of the 0 dB frequency of the first amplifier circuit, Q=(L/C nx ) 1/2 /R o , and k c =C o /C nx , ranges of Q and k c are expressed by:
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h
(
Ω
a
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)
❘
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-
2
=
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+
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3
3
+
4
3
3
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k
c
-
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)
-
4
+
4
3
9
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Q
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h
(
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a
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-
2
≤
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,
0
.
5
<
k
c
≤
1
.25
.