Broadband Transconductance Amplifier
AssigneeFujitsu Semiconductor Limited
InventorsDong-Jun Yang, Mohammed Shah Alam
Life of this patent
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Abstract
A transconductance amplifier having an input terminal for receiving an input signal and an output terminal for communicating an output signal based on the input signal, the transconductance amplifier may include a gain transistor and a variable capacitance. The gain transistor may have a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the output terminal of the transconductance amplifier. The variable capacitance may be coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor.
Claims20
A transconductance amplifier having an input terminal for receiving an input signal and an output terminal for communicating an output signal based on the input signal, the transconductance amplifier comprising:
- a gain transistor having a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the output terminal of the transconductance amplifier;
- and
- a variable capacitance coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor.
A wireless communication element, comprising:
- a transmit path configured to convert a first digital signal into a first modulated wireless communication signal and transmit the first modulated wireless communication signal;
- and
- a receive path configured to receive a second modulated wireless communication signal and convert the second wireless communication signal into a second digital signal, the receive path comprising a transconductance amplifier having an input terminal for receiving an input signal and an output terminal for communicating an output signal based on the input signal, the transconductance amplifier comprising:
- a gain transistor having a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the output terminal of the transconductance amplifier;
- and
- a variable capacitance coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor.
A method comprising:
- determining an operating frequency of a transconductance amplifier comprising:
- a gain transistor having a gate terminal coupled to an input terminal of the transconductance amplifier, a first non-gate terminal, and a second non-gate terminal;
- and
- a variable capacitance coupled between the gate terminal of the gain transistor and the first non-gate terminal of the gain transistor;
- and
- selecting a capacitance of the variable capacitance based on the operating frequency such that at least one of a magnitude of the input impedance of the input terminal of the transconductance amplifier and a quality factor associated with the input impedance remains substantially constant over a plurality of operating frequencies of the transconductance amplifier.
Dependencies are inferred from the claim text.