Tunable transconductance-capacitance filter
AssigneeQUALCOMM Incorporated
InventorsMehran BAKHSHIANI, Youssef Osama HASSAN, Timothy Donald GATHMAN, Aleksandar Miodrag TASIC
Life of this patent
Estimating the term…
Abstract
In some aspects, a filter circuit may include an input stage comprising a resistor-capacitor (RC) circuit configured to receive an input voltage and convert the input voltage to an input current. The filter circuit may include a current mirror stage comprising a transistor network and one or more differential capacitors configured to receive the input current and apply a gain to the input current to generate an output current. The filter circuit may include an output stage comprising an output capacitor coupled between an output from the current mirror stage and an input to an analog-to-digital converter (ADC) to maintain the output current.
Claims20
A baseband filter, comprising:
- a transimpedance amplifier to receive a down-converted radio frequency (RF) signal and to filter and amplify the down-converted RF signal;
- a filter configured to receive the amplified down-converted RF signal and to filter the amplified down-converted RF signal to remove undesired frequency components from a desired baseband signal, wherein the filter comprises:
- a first stage, associated with a first pole, to convert an input voltage associated with the amplified down-converted RF signal to an input current;
- a second stage, associated with a second pole, to apply a gain to the input current to generate an output current;
- and
- a third stage, associated with a third pole, to maintain the output current and provide the desired baseband signal to an analog-to-digital converter (ADC);
- and
- a programming interface to receive one or more instructions to tune one or more of the first pole, the second pole, the third pole, or the gain applied to the input current based on a frequency associated with the down-converted RF signal.
A filter, comprising:
- an input stage comprising a resistor-capacitor (RC) circuit configured to receive an input voltage and convert the input voltage to an input current;
- a current mirror stage comprising a transistor network and one or more differential capacitors configured to receive the input current and apply a gain to the input current to generate an output current;
- and
- an output stage comprising an output capacitor coupled between an output from the current mirror stage and an input to an analog-to-digital converter (ADC) to maintain the output current.
A method, comprising:
- receiving a down-converted radio frequency (RF) signal at a circuit;
- programming a gain associated with the circuit according to a first frequency associated with the down-converted RF signal;
- and
- filtering, by the circuit, the down-converted RF signal to remove undesired frequency components from a desired baseband signal associated with a second frequency, wherein filtering the down-converted RF signal includes:
- converting, at a transconductance (gm) stage of the circuit, an input voltage associated with the down-converted RF signal to an input current;
- applying, at a current mirror (cm) stage of the circuit, the programmed gain to the input current to generate an output current;
- and
- providing, at a capacitance (c) stage of the circuit, capacitance to maintain the output current for the desired baseband signal;
- and
- providing, by the circuit, the desired baseband signal associated with the second frequency to an analog-to-digital converter (ADC).
Dependencies are inferred from the claim text.