US 2013/0155748 A1 · Conversion Circuit

Abstract

A conversion circuit (20) for converting a complex analog input signal having an in-phase, I, component and a quadrature-phase, Q, component resulting from frequency down conversion of a radio-frequency, RF, signal (XRF) to a frequency band covering 0 Hz into a digital representation is disclosed. It comprises a channel-selection filter unit (40) arranged to filter the complex analog input signal, thereby generating a channel-filtered I and Q components, and one or more processing units (53, 53a-b). Each processing unit comprises four mixers (60-75) for generating a first and a second frequency-translated I component and a first and a second channel-filtered Q component based on two LO signals with equal LO frequency and a 90° mutual phase shift. Furthermore, each processing unit comprises a combiner unit (85, 120) for generating a first, a second, a third, and a fourth combined signal proportional to sums and differences between said frequency translated I and Q components. The first and the fourth combined signals form a first complex signal, and the second and the third combined signals form a second complex signal. Each processing unit further comprises four ADCs (110a-d, 115a-d) for providing digital representations of the first complex signal and the second complex signal for forming said digital representation of the analog complex input signal. A related radio receiver circuit and a related electronic apparatus are also disclosed.

Claims19

Dependent claims

1-19. (canceled)

A conversion circuit for converting a complex analog input signal having an in-phase (I) component and a quadrature-phase (Q) component resulting from frequency down conversion of a radio frequency (RF) signal to a frequency band covering 0 Hz into a digital representation, the conversion circuit comprising:

a channel selection filter unit configured to filter the complex analog input signal, thereby generating a channel-filtered I component and a channel-filtered Q component, wherein the channel selection filter unit has a passband that covers 0 Hz;
and
one or more processing units, each comprising:
a first mixer arranged to mix the channel-filtered I component with a first local-oscillator (LO) signal to generate a first frequency-translated I component;
a second mixer arranged to mix the channel-filtered I component with a second LO signal to generate a second frequency-translated I component;
a third mixer arranged to mix the channel-filtered Q component with the first LO signal to generate a first frequency-translated Q component;
a fourth mixer arranged to mix the channel-filtered Q component with the second LO signal to generate a second frequency-translated Q component;
a combiner unit configured to generate:
a first combined signal proportional to a sum of the first frequency translated I component and the second frequency-translated Q component;
a second combined signal proportional to a difference between the first frequency translated I component and the second frequency-translated Q component;
a third combined signal proportional to a sum of the second frequency-translated I component and the first frequency-translated Q-component;
and
a fourth combined signal proportional to a difference between the first frequency-translated Q component and the second frequency-translated I component;
wherein the first and the fourth combined signals form a first complex signal;
wherein the second and the third combined signals form a second complex signal;
a first analog-to-digital converter (ADC), a second ADC, a third ADC, and a fourth ADC configured to provide digital representations of the first complex signal and the second complex signal for forming the digital representation of the analog complex input signal;
wherein the first and the second LO signal of a given processing unit have a common LO frequency associated with the processing unit and a mutual 90° phase shift.

14 more elements

A radio receiver circuit comprising:

a conversion circuit for converting a complex analog input signal having an in-phase (I) component and a quadrature-phase (Q) component resulting from frequency down conversion of a radio frequency (RF) signal to a frequency band covering 0 Hz into a digital representation, comprising:
a channel selection filter unit configured to filter the complex analog input signal, thereby generating a channel-filtered I component and a channel-filtered Q component, wherein the channel selection filter unit has a passband that covers 0 Hz;
and
one or more processing units, each comprising:
a first mixer arranged to mix the channel-filtered I component with a first local-oscillator (LO) signal to generate a first frequency-translated I component;
a second mixer arranged to mix the channel-filtered I component with a second LO signal to generate a second frequency-translated I component;
a third mixer arranged to mix the channel-filtered Q component with the first LO signal to generate a first frequency-translated Q component;
a fourth mixer arranged to mix the channel-filtered Q component with the second LO signal to generate a second frequency-translated Q component;
a combiner unit configured to generate:
a first combined signal proportional to a sum of the first frequency translated I component and the second frequency-translated Q component;
a second combined signal proportional to a difference between the first frequency translated I component and the second frequency-translated Q component;
a third combined signal proportional to a sum of the second frequency-translated I component and the first frequency-translated Q-component;
and
a fourth combined signal proportional to a difference between the first frequency-translated Q component and the second frequency-translated I component;
wherein the first and the fourth combined signals form a first complex signal;
wherein the second and the third combined signals form a second complex signal;
a first analog-to-digital converter (ADC), a second ADC, a third ADC, and a fourth ADC configured to provide digital representations of the first complex signal and the second complex signal for forming the digital representation of the analog complex input signal;
wherein the first and the second LO signal of a processing unit have a common LO frequency associated with the processing unit and a mutual 90° phase shift;
a quadrature mixer for generating the complex analog input signal of the conversion circuit by frequency down-conversion of a RF signal.

16 more elements

Dependencies are inferred from the claim text.

Conversion Circuit

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Conversion Circuit

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Abstract

Claims19