Bandpass amplifier
View Patent ↗The present invention discloses a bandpass amplifier having gain and bandpass performance. The bandpass amplifier includes an input match unit for matching the gain of the amplifier and having a first filter response; a first bias unit electrically connected to the input match unit for driving the first terminal of the amplifier and having a first high pass filter response; a gain stage electrically connected to the first bias unit for providing the flat gain of the amplifier; a second bias unit electrically connected to the gain stage for driving the second terminal of the amplifier and having a second high pass filter response; and an output match unit electrically connected to the second bias unit for matching the gain of the amplifier and having a second filter response.
1. An amplifier with three terminals, fabricated on a single chip and having gain and filter performance in a microwave to millimeter-wave range, comprising:
an input match unit, used for matching the gain of the amplifier and having a first low pass filter response;
a first bias unit, electrically connected to the input match unit, used for driving a first terminal of the amplifier and having a first high pass filter response;
a gain stage, electrically connected to the first bias unit, a resistor, a fifth inductor and a first capacitor in series connected between two terminals of the gain stage, used for providing a flat gain of the amplifier;
a second bias unit, electrically connected to the gain stage, used for driving a second terminal of the amplifier and having a second high pass filter response; and
an output match unit, electrically connected to the second bias unit, used for matching the gain of the amplifier and having a second low pass filter response;
where both the input match unit and the output match unit comprise two first inductors with an inductance L 1 , one second inductor with an inductance L 2 and two second capacitors with a capacitance C 2 for determining a cutoff frequency ω cT and a transmission-zero frequency ω zT of the low pass filter response, and
wherein both the first bias unit and the second bias unit comprise a fourth inductor with an inductance L 4 , a third capacitor with an inductance C 3 and a fourth capacitor with a capacitance C 4 , for determining a cutoff frequency ω cL and a transmission-zero frequency ω zL of the high pass filter response.
2. An amplifier as claimed in claim 1 , wherein the gain stage is a PHEMT, which is implemented on a semiconductor substrate of AlGaAs/InGaAs/GaAs compound.
3. A filter circuit, fabricated on a single chip to have gain and filter performance in a microwave to millimeter-wave range, comprising:
an amplifier having three terminals;
an input match unit, used for matching a gain of an amplifier, having a low pass filter response;
a first bias unit, electrically connected to the input match unit, used for driving a first terminal of the amplifier and having a high pass filter response;
a gain stage, electrically connected to the first bias unit, a resistor, a fifth inductor and a first capacitor in series connected between two terminals of the gain stage, for providing a flat gain of the amplifier;
a second bias unit, electrically connected to the gain stage, used for driving a second terminal of the amplifier and having a second high pass filter response; and
an output match unit, electrically connected to the second bias unit, used for matching the gain of the amplifier and having a second low pass filter response;
where both the input match unit and the output match unit comprise two first inductors with an inductance L 1 , one second inductor with an inductance L 2 and two second capacitors with a capacitance C 2 , for determining a cutoff frequency ω cT and a transmission-zero frequency ω zT of the low pass filter response, and
wherein both the first bias unit and the second bias unit comprise a fourth inductor with an inductance L 4 , a third capacitor with an inductance C 3 and a fourth capacitor with a capacitance C 4 , for determining a cutoff frequency ω cL and a transmission-zero frequency ω zL of the high pass filter response.
4. A receiver comprising an antenna, a first bandpass amplifier, a mixer having an associated local oscillator, a second bandpass amplifier, and a detector means for determining whether a particular signal has been received,
wherein the first and second bandpass amplifiers are fabricated on a single chip to have gain and filter performance in the microwave to millimeter-wave range, each comprises
an input match unit, used for matching a gain of the amplifier and having a low pass filter response;
a first bias unit, electrically connected to the input match unit, used for driving a first terminal of the amplifier and having a high pass filter response;
a gain stage, electrically connected to the first bias unit, a resistor, a fifth inductor and a first capacitor in series connected between two terminals of the gain stage, for providing the flat gain of the amplifier;
a second bias unit, electrically connected to the gain stage, for driving a second terminal of the amplifier and having the high pass filter response; and
an output match unit, electrically connected to the second bias unit, used for matching the gain of the amplifier and having the low pass filter response;
where both the input match unit and the output match unit comprise two first inductors with an inductance L 1 , one second inductor with an inductance L 2 and two second capacitors with a capacitance C 2 for determining a cutoff frequency ω cT and a transmission-zero frequency ω zT of the low pass filter response, and
wherein both the first bias unit and the second bias unit comprise a fourth inductor with an inductance L 4 , a third capacitor with an inductance C 3 and a fourth capacitor with a capacitance C 4 , for determining a cutoff frequency ω cL and a transmission-zero frequency ω zL of the high pass filter response.
5. An amplifier as claimed in claim 1 , wherein the cutoff frequency ω cT and a transmission-zero frequency ω zT of the low pass filter response are expressed as:
ω
cT
=
1
(
L
1
+
L
2
)
C
2
,
and
ω
zT
=
1
L
2
C
2
.
6. An amplifier as claimed in claim 1 , wherein the cutoff frequency ω cL and a transmission-zero frequency ω zL of the high pass filter response are expressed as:
ω
cL
=
1
L
4
(
1
C
3
+
1
C
4
)
,
and
ω
zL
=
1
L
4
C
4
.
7. An amplifier as claimed in claim 1 , wherein the resistor, the fifth inductor and the first capacitor in series connected between the two terminals of the gain stage is an external shunt feedback path of the gain stage.
8. An amplifier as claimed in claim 1 , wherein the flat gain of the amplifier is conducted by using a spiral inductor.
9. An amplifier as claimed in claim 1 , wherein the first capacitor is one of an inter-digital capacitor and metal-insulator-metal insulator (MIM) capacitor.
10. An amplifier as claimed in claim 1 , wherein the flat gain of the amplifier is a ripple less than 1 dB from 20 to 40 GHz.
11. A filter circuit as claimed in claim 3 , wherein the cutoff frequency ω zT and the transmission zero frequency ω zL of the low pass filter response are expressed as:
ω
cT
=
1
(
L
1
+
L
2
)
C
2
,
and
ω
zT
=
1
L
2
C
2
.
12. A filter circuit as claimed in claim 3 , wherein the cutoff frequency ω cL and the transmission zero frequency ω zL of the high pass filter response are expressed as:
ω
cL
=
1
L
4
(
1
C
3
+
1
C
4
)
,
and
ω
zL
=
1
L
4
C
4
.
13. A filter circuit as claimed in claim 3 , wherein the fifth inductor is a spiral inductor.
14. A filter circuit as claimed in claim 3 , wherein the first capacitor is one of an inter-digital capacitor and metal-insulator-metal insulator (MIM) capacitor.
15. A filter circuit as claimed in claim 3 , wherein the amplifier has the flat gain with a ripple less than 1 dB from 20 to 40 GHz.
16. A filter circuit as claimed in claim 3 , wherein the gate stage is a PHEMT, implemented on a semiconductor substrate of AlGaAs/InGaAs/GaAs compound.
17. A receiver as claimed in claim 4 , wherein the cutoff frequency ω zT and the transmission zero frequency ω zL of the low pass filter response are expressed as:
ω
cT
=
1
(
L
1
+
L
2
)
C
2
,
and
ω
zT
=
1
L
2
C
2
.
18. A receiver as claimed in claim 4 , wherein the cutoff frequency ω cT and a transmission-zero frequency ω zT of the low pass filter response are expressed as:
ω
cT
=
1
(
L
1
+
L
2
)
C
2
ω
zT
=
1
L
2
C
2
.
19. A receiver as claimed in claim 4 , wherein the cutoff frequency ω cL and a transmission-zero frequency ω zL of the high pass filter response are expressed as:
ω
cL
=
1
L
4
(
1
C
3
+
1
C
4
)
ω
zL
=
1
L
4
C
4
.
20. A receiver as claimed in claim 4 , wherein the gain stage is a PHEMT, implemented on a semiconductor substrate of AlGaAs/InGaAs/GaAs compound.