US 10,581,406 B2Granted

Digital filtering for analog gain/phase errors

AssigneeTexas Instruments Incorporated

InventorsJawaharlal Tangudu, Karthik Khanna S, Chandrasekhar Sriram, Rajendrakumar Joish, Viswanathan Nagarajan

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Abstract

A circuit for digital filtering an analog signal converted to digital, including an analog circuit to generate an analog signal, the analog signal including phase and/or gain errors. An analog-to-digital converter (ADC) to convert the analog signal to a digital signal output to a digital signal path. A frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with at least one complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.

Claims20

Dependent claims

A circuit for use in a system for radio frequency (RF) communication including a transmit (TX) end, and a receive (RX) end to receive an RF RX signal at an RF frequency within a target frequency band, the circuit comprising:

an input port to receive the RF RX signal;
an analog-to-digital converter (ADC) with an input coupled through an analog signal path to the input port, and with an output coupled through a digital signal path to an output port;
a digital step attenuator (DSA) coupled to the analog signal path, and configured to attenuate the RF RX signal with selectable DSA attenuation steps based on a DSA control signal, and generate a DSA output that includes, for at least some of the DSA attenuation steps, DSA phase errors and/or DSA gain errors;
the ADC configured to convert an input signal corresponding to the DSA output to a digital ADC output provided to the digital signal path;
downconverter circuitry included in at least one of the analog signal path and the digital signal path, and configured to downconvert a signal at the RF frequency to a signal at a baseband frequency;
a DSA frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with a complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.

3 more elements

A circuit for correcting frequency-dependent errors in a digital step attenuator (DSA), comprising:

analog circuitry to provide an analog signal in an analog signal path;
DSA circuitry configured to attenuate the analog signal with selectable DSA attenuation steps based on a DSA control signal, and generate a DSA output that includes, for at least some of the DSA attenuation steps, DSA phase errors and/or DSA gain errors;
an analog-to-digital converter (ADC) to convert the analog signal to a digital signal output to a digital signal path;
the ADC configured to convert an input signal corresponding to the DSA output to a digital ADC output provided to the digital signal path;
a DSA frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with a complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.

2 more elements

Dependencies are inferred from the claim text.