Radio frequency low noise amplifier with automatic gain control
First Claim
1. A low noise amplifier comprising:
- a first transconductance device having a control electrode for receiving a first input signal, and a first current electrode;
a first load device having a first terminal coupled to a first power supply voltage terminal and a second terminal coupled to said first current electrode of said first transconductance device and forming a first output voltage signal thereon;
a second transconductance device having a control electrode for receiving a second input signal, and a first current electrode;
a second load device having a first terminal coupled to said first power supply voltage terminal and a second terminal coupled to said first current electrode of said second transconductance device and forming a second output voltage signal thereon; and
an attenuation device coupled between said first current electrode of said first transconductance device and said first current electrode of said second transconductance device, and having a control input terminal for receiving a control voltage thereon;
wherein said attenuation device comprises a plurality of exponentially-weighted attenuation devices.
1 Assignment
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Accused Products
Abstract
A low noise amplifier (500) includes a first transconductance device (326) having a control electrode for receiving a first input signal, and a first current electrode; a first load device (322) having a first terminal coupled to a first power supply voltage terminal and a second terminal coupled to the first current electrode of the first transconductance device (326) and forming a first output voltage signal; a second transconductance device (336) having a control electrode for receiving a second input signal, and a second current electrode; a second load device (332) having a first terminal coupled to the first power supply voltage terminal and a second terminal coupled to the first current electrode of the second transconductance device (336) and forming a second output voltage signal; and an attenuation device (340) coupled between the first current electrodes of the first (326) and second (336) transconductance devices and having a control input terminal for receiving a control voltage thereon.
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Citations
31 Claims
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1. A low noise amplifier comprising:
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a first transconductance device having a control electrode for receiving a first input signal, and a first current electrode; a first load device having a first terminal coupled to a first power supply voltage terminal and a second terminal coupled to said first current electrode of said first transconductance device and forming a first output voltage signal thereon; a second transconductance device having a control electrode for receiving a second input signal, and a first current electrode; a second load device having a first terminal coupled to said first power supply voltage terminal and a second terminal coupled to said first current electrode of said second transconductance device and forming a second output voltage signal thereon; and an attenuation device coupled between said first current electrode of said first transconductance device and said first current electrode of said second transconductance device, and having a control input terminal for receiving a control voltage thereon; wherein said attenuation device comprises a plurality of exponentially-weighted attenuation devices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A low noise amplifier comprising:
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a first inductor having a first terminal coupled to a first power supply voltage terminal, and a second terminal forming a first output voltage signal thereon; a first transistor having a first current electrode coupled to said second terminal of said first inductor, a control electrode coupled to said first power supply voltage terminal, and a second current electrode; a second transistor having a first current electrode coupled to said second current electrode of said first transistor, a control electrode for receiving a first input signal, and a second current electrode; a second inductor having a first terminal coupled to said second current electrode of said second transistor, and a second terminal coupled to a second power supply voltage terminal; a third inductor having a first terminal coupled to said first power supply voltage terminal, and a second terminal forming a second output voltage signal thereon; a third transistor having a first current electrode coupled to said second terminal of said third inductor, a control electrode coupled to said first power supply voltage terminal, and a second current electrode; a fourth transistor having a first current electrode coupled to said second current electrode of said third transistor, a control electrode for receiving a second input signal, and a second current electrode; a fourth inductor having a first terminal coupled to said second current electrode of said fourth transistor, and a second terminal coupled to said second power supply voltage terminal; and an attenuation device coupled between said first current electrode of said first transistor and said first current electrode of said third transistor, and having a control input terminal for receiving a control voltage thereon. - View Dependent Claims (16, 17, 18)
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19. A low noise amplifier comprising:
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an amplifier having a first input terminal for receiving a first input signal, a first output terminal for providing a first output signal, and a feedback input terminal for receiving a control voltage, wherein said control voltage determines a gain of said amplifier; and a bias circuit having an input terminal for receiving a control signal, and an output terminal coupled to said first input terminal of said amplifier for providing a bias voltage thereto, wherein said bias circuit is responsive to said control signal to operate in one of first and second modes, wherein in said first mode said bias circuit biases said amplifier to operate in a substantially constant transconductance mode, and in said second mode said bias circuit biases said amplifier to operate in a substantially constant saturation voltage mode. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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28. A method for operating a low noise amplifier with automatic gain control comprising the steps of:
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determining a power level of an output signal of the low noise amplifier; providing a control voltage in response to said power level; biasing the low noise amplifier to operate in a constant transconductance mode in response to said control voltage being less than a predetermined voltage; and biasing the low noise amplifier to operate in a constant saturation voltage mode in response to said control voltage being greater than said predetermined voltage. - View Dependent Claims (29, 30)
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31. A low noise amplifier comprising:
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a first transconductance device having a control electrode for receiving a first input signal, and a first current electrode; a first load device having a first terminal coupled to a first power supply voltage terminal and a second terminal coupled to said first current electrode of said first transconductance device and forming a first output voltage signal thereon; a second transconductance device having a control electrode for receiving a second input signal, and a first current electrode; a second load device having a first terminal coupled to said first power supply voltage terminal and a second terminal coupled to said first current electrode of said second transconductance device and forming a second output voltage signal thereon; an attenuation device coupled between said first current electrode of said first transconductance device and said first current electrode of said second transconductance device, and having a control input terminal for receiving a control voltage thereon; and a biasing network coupled between said control electrodes of said first and second transconductance devices, said biasing network comprising; a first resistor having a first terminal coupled to said control electrode of said first transconductance device, and a second terminal; a second resistor having a first terminal coupled to said control electrode of said second transconductance device, and a second terminal coupled to said second terminal of said first resistor; a current source having a first terminal coupled to said first power supply voltage terminal, and a second terminal; and a transistor having a first current electrode coupled to said second terminal of said current source, a control electrode coupled to said first current electrode thereof, and a second current electrode coupled to a second power supply voltage terminal.
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Specification