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US 7,466,193 B2Granted
Device and method of eliminating DC offset
AssigneeSamsung Electronics Co., Ltd.
InventorJae-Wan Kim
Life of this patent
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Abstract
A DC offset elimination device includes a first signal path that delivers a differential input signal pair from an input node to an output node and a second signal path that delivers a differential output signal pair from the output node to the input node. The second signal path includes a first transconductor having an input terminal coupled to the output node, an amplifier having an input terminal coupled to an output terminal of the first transconductor, a capacitor coupled in parallel to the amplifier, and a second transconductor coupled to the output terminal of the amplifier and to the input node.
Claims34
A device for eliminating a DC offset, comprising:
- a first signal path for delivering a differential input signal pair from an input node to an output node;
- and
- a second signal path for feeding back a differential output signal pair from the output node to the input node, the second signal path including:
- a first transconductor having an input terminal coupled to the output node;
- an amplifier having an input terminal coupled to an output terminal of the first transconductor;
- a capacitor coupled in parallel to the amplifier;
- and
- a second transconductor coupled to the output terminal of the amplifier and to the input node,
- wherein the first transconductor comprises a differential operational transconductance amplifier (OTA).
6 more elements
A direct conversion receiver comprising:
- an RF module configured to receive an RF signal;
- a mixer configured to convert the RF signal into a baseband signal pair;
- and
- a DC offset elimination device configured to eliminate a DC offset of the baseband signal pair, the DC offset elimination device including:
- a first signal path configured to deliver the baseband signal pair from an input node to an output node;
- and
- a second signal path for feeding back a differential output signal pair from the output node to the input node, the second signal path including:
- a first transconductor having an input terminal coupled to the output node;
- an amplifier having an input terminal coupled to an output terminal of the first transconductor;
- a capacitor coupled in parallel to the amplifier;
- and
- a second transconductor coupled to the output terminal of the amplifier and to the input node,
- wherein the first transconductor comprises a differential operational transconductance amplifier (OTA).
10 more elements
A method of eliminating a DC offset, comprising:
- providing a differential output signal pair by delivering a differential input signal pair from an input node to an output node through a first signal path;
- converting the differential output signal pair to a current pair;
- integrating the current pair into a voltage pair;
- converting the voltage pair into a feedback current pair;
- and
- providing the feedback current pair to the input node,
- wherein converting the differential output signal pair to the current pair comprises:
- providing a bias current:
- providing a first current pair corresponding to a first portion of the bias current in response to the differential output signal pair;
- bypassing a second portion of the bias current in response to the differential output signal pair, a sum of the first portion and the second portion being equal to the bias current;
- and
- mirroring the first current pair to output the mirrored current pair as the current pair.
9 more elements
The method of c1 aim 23, wherein converting the differential output signal pair to the current pair comprises:
- providing a bias current, a magnitude of the bias current being varied in response to a control signal;
- providing a first current pair corresponding to a first portion of the bias current in response to the differential output signal pair;
- bypassing a second portion of the bias current in response to the differential output signal pair;
- and
- mirroring the first current pair to output the mirrored current pair as the current pair.
2 more elements
A method of eliminating a DC offset, comprising:
- providing a differential output signal pair by delivering a differential input signal pair from an input node to an output node through a first signal path;
- converting the differential output signal pair to a current pair;
- integrating the current pair into a voltage pair;
- converting the voltage pair into a feedback current pair;
- and
- providing the feedback current pair to the input node,
- wherein converting the differential output signal pair to the current pair comprises:
- providing a bias current;
- providing a first current pair corresponding to a first portion of the bias current pair in response to the differential output signal pair;
- providing a second current pair corresponding to a second portion of the bias current pair in response to the differential output signal pair, a sum of the first portion and the second portion being equal to the bias current;
- selecting one of bypassing the second current pair or summing the first and the second current pairs;
- and
- mirroring one of the first current pair and the sum of the first and second current pairs to output the current pair.
10 more elements
A direct conversion method comprising:
- down-converting a received RF signal to provide a baseband signal pair;
- providing a differential output signal pair by delivering the baseband signal pair from an input node to an output node through a first signal path;
- converting the differential output signal pair to a current pair;
- integrating the current pair into a voltage pair;
- converting the voltage pair into a feedback current pair;
- and
- providing the feedback current pair to the input node to eliminate a DC offset in the baseband signal pair,
- wherein converting the differential output signal pair to the current pair comprises:
- providing a bias current;
- providing a first current pair corresponding to a first portion of the bias current in response to the differential output signal pair;
- bypassing a second portion of the bias current in response to the differential output signal pair, a sum of the first portion and the second portion being equal to the bias current;
- and
- mirroring the first current pair to output the mirrored current pair as the current pair.
10 more elements
A direct conversion method comprising:
- down-converting a received RF signal to provide a baseband signal pair;
- providing a differential output signal pair by delivering the baseband signal pair from an input node to an output node through a first signal path;
- converting the differential output signal pair to a current pair;
- integrating the current pair into a voltage pair;
- converting the voltage pair into a feedback current pair;
- and
- providing the feedback current pair to the input node to eliminate a DC offset in the baseband signal pair,
- wherein converting the differential output signal pair to the current pair comprises:
- providing a bias current;
- providing a first current pair corresponding to a first portion of the bias current in response to the differential output signal pair;
- providing a second current pair corresponding to a second portion of the bias current in response to the differential output signal pair, a sum of the first portion and the second portion being equal to the bias current;
- selecting one of bypassing the second current pair or summing the first and the second current pairs;
- and
- mirroring one of the first current pair and the sum of the first and second current pairs to output the current pair.
11 more elements
Dependencies are inferred from the claim text.