US 7,480,343 B2Granted

Transceiver architecture with reduced VCO-pulling sensitivity

AssigneeEricsson Technology Licensing AB

InventorsJohannes Wilhelmus Eikenbroek, Paulus Thomas Maria Van Zeijl

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Abstract

An output signal is generated for transmission in a telecommunications systems. This may involve generating an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal; and generating an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal. An output signal for transmission is generated by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF. The first and second radio frequency mixer signals are generated by generating a voltage controlled oscillator (VCO) output signal having a frequency, fVCO, such that f VCO = ( n + 1 2 ) · f RF , wherein n=1, 2, 3, . . . ; and generating one or more fractional frequency divided signals from the VCO output signal, wherein each of the one or more fractional frequency divided signals has a frequency equal to fRF.

Claims28

Dependent claims

A transmitter for use in a telecommunications system, comprising:

a first mixer that generates an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal;
a second mixer that generates an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal, wherein a relative phase-difference between the in-phase and alternative-phase baseband signals is α radians, wherein |α|≠π/2;
combining circuitry that generates an output signal for transmission by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF;
and
a synthesizer that generates the first and second radio frequency mixer signals, the synthesizer comprising:
a voltage controlled oscillator (VCO) that generates a VCO output signal having a frequency, fVCO, such that
f
VCO
=
(
n
+
1
2
)
·
f
RF
,
wherein n=1,2,3, . . . ;
and
circuitry, including a fractional frequency divider that generates the first and second radio frequency mixer signals from the VCO output signal, wherein each of the first and second radio frequency mixer signals has a frequency equal to fRF, and wherein a relative phase difference between the first and second radio frequency mixer signals is α radians,
wherein:
n=1;
the fractional frequency divider is a divide-by-N fractional frequency divider with N=3/2, and
the fractional frequency divider comprises:
logic that, for every three successive transitions of the VCO output signal, generates a first fractional frequency divider output signal such that the first fractional frequency divider output signal transitions in response to each of first and second transitions of the three successive transitions of the VCO output signal, and the first fractional frequency divider output signal remains steady in response to a third transition of the three successive transitions of the VCO output signal;
and
logic that, for said every three successive transitions of the VCO output signal, generates a second fractional frequency divider output signal such that the second fractional frequency divider output signal transitions in response to each of the second and third transitions of the three successive transitions of the VCO output signal, and the second fractional frequency divider output signal remains steady in response to the first transition of the three successive transitions of the VCO output signal.

26 more elements

A transceiver comprising:

a transmitter for use in a telecommunications system, comprising:
a first mixer that generates an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal;
a second mixer that generates an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal, wherein a relative phase-difference between the in-phase and alternative-phase baseband signals is α radians, wherein |α|≠π/2;
combining circuitry that generates an output signal for transmission by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF;
and
a synthesizer that generates the first and second radio frequency mixer signals, the synthesizer comprising:
a voltage controlled oscillator (VCO) that generates a VCO output signal having a frequency, fVCO, such that
f
VCO
=
(
n
+
1
2
)
·
f
RF
,
wherein n=1,2,3, . . . ;
and
circuitry, including a fractional frequency divider that generates the first and second radio frequency mixer signals from the VCO output signal, wherein each of the first and second radio frequency mixer signals has a frequency equal to fRF, and wherein a relative phase difference between the first and second radio frequency mixer signals is α radians;
and
a receiver comprising:
a first mixer that generates a first mixed signal by mixing a received radio frequency signal with a third radio frequency mixer signal;
a second mixer that generates a second mixed signal by mixing the received radio frequency signal with a fourth radio frequency mixer signal, wherein a relative phase difference between the third and fourth radio frequency mixer signals is α radians;
and
processing circuitry that receives the first and second mixed signals and generates therefrom an in-phase receiver signal and a quadrature-phase receiver signal, wherein a relative phase difference between the in-phase receiver signal and the quadrature-phase receiver signal is π/2 radians,
wherein:
α=2π/3;
and
the processing circuitry generates the in-phase receiver signal, i(t), and the quadrature-phase receiver signal, q(t), from the first mixed signal, x(t), and the second mixed signal, y(t), in accordance with:
i(t)=x(t)
⁢
q
⁡
(
t
)
=
1
3
⁢
x
⁡
(
t
)
+
2
3
⁢
y
⁡
(
t
)
.

56 more elements

A transceiver comprising:

a transmitter for use in a telecommunications system, comprising:
a first mixer that generates an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal;
a second mixer that generates an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal, wherein a relative phase-difference between the in-phase and alternative-phase baseband signals is α radians, wherein |α|≠π/2;
combining circuitry that generates an output signal for transmission by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF;
and
a synthesizer that generates the first and second radio frequency mixer signals, the synthesizer comprising:
a voltage controlled oscillator (VCO) that generates a VCO output signal having a frequency, fVCO, such that
f
VCO
=
(
n
+
1
2
)
·
f
RF
,
wherein n=1,2,3, . . . ;
and
circuitry, including a fractional frequency divider that generates the first and second radio frequency mixer signals from the VCO output signal, wherein each of the first and second radio frequency mixer signals has a frequency equal to fRF, and wherein a relative phase difference between the first and second radio frequency mixer signals is α radians;
and
a receiver comprising:
a first mixer that generates a first mixed signal by mixing a received radio frequency signal with a third radio frequency mixer signal;
a second mixer that generates a second mixed signal by mixing the received radio frequency signal with a fourth radio frequency mixer signal, wherein a relative phase difference between the third and fourth radio frequency mixer signals is α radians;
and
processing circuitry that receives the first and second mixed signals and generates therefrom an in-phase receiver signal and a quadrature-phase receiver signal, wherein a relative phase difference between the in-phase receiver signal and the quadrature-phase receiver signal is π/2 radians,
wherein:
the processing circuitry generates the in-phase receiver signal, i(t), in accordance with a first function that includes adding the first mixed signal, x(t), and the second mixed signal, y(t);
and
the processing circuitry generates the quadrature-phase receiver signal, q(t), in accordance with a second function that includes determining a difference between the first mixed signal, x(t), and the second mixed signal, y(t).

30 more elements

A method of generating an output signal for transmission in a telecommunications system, the method comprising:

generating an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal;
generating an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal, wherein a relative phase difference between the in-phase and alternative-phase baseband signals is α radians, wherein |α|≠π/2;
generating an output signal for transmission by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF;
and
generating the first and second radio frequency mixer signals by performing:
generating a voltage controlled oscillator (VCO) output signal having a frequency, fVCO, such that
f
VCO
=
(
n
+
1
2
)
·
f
RF
,
wherein n=1,2,3, . . . ;
and
generating the first and second radio frequency mixer signals from the VCO output signal, wherein each of the first and second radio frequency mixer signals has a frequency equal to fRF,
wherein:
n=1;
generating the first and second radio frequency mixer signals includes dividing the VCO output signal by an amount N, where N=3/2;
generating the first radio frequency mixer signal comprises, for every three successive transitions of the VCO output signal, generating a first fractional frequency divided signal such that the first fractional frequency divided signal transitions in response to each of first and second transitions of the three successive transitions of the VCO output signal, and the first fractional frequency divided signal remains steady in response to a third transition of the three successive transitions of the VCO output signal;
and
generating the second radio frequency mixer signal comprises, for said every three successive transitions of the VCO output signal, generating a second fractional frequency divided signal such that the second fractional frequency divided signal transitions in response to each of the second and third transitions of the three successive transitions of the VCO output signal, and the second fractional frequency divided signal remains steady in response to the first transition of the three successive transitions of the VCO output signal.

25 more elements

A method of generating an output signal for transmission in a telecommunications system, the method comprising:

generating an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal;
generating an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal, wherein a relative phase difference between the in-phase and alternative-phase baseband signals is α radians, wherein |α|≠π/2;
generating an output signal for transmission by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF;
and
generating the first and second radio frequency mixer signals by performing:
generating a voltage controlled oscillator (VCO) output signal having a frequency, fVCO, such that
f
VCO
=
(
n
+
1
2
)
·
f
RF
,
wherein n=1,2,3, . . . ;
and
generating the first and second radio frequency mixer signals from the VCO output signal, wherein each of the first and second radio frequency mixer signals has a frequency equal to fRF,
wherein n=1,
the method further comprises a receiver process that comprises:
generating a first mixed signal by mixing a received radio frequency signal with a third radio frequency mixer signal;
generating a second mixed signal by mixing the received radio frequency signal with a fourth radio frequency mixer signal, wherein a relative phase difference between the third and fourth radio frequency mixer signals is α radians;
and
generating, from the first and second mixed signals, an in-phase receiver signal and a quadrature-phase receiver signal, wherein a relative phase difference between the in-phase receiver signal and the quadrature-phase receiver signal is π/2 radians,
and wherein:
α=2π/3;
and
the method comprises generating the in-phase receiver signal, i(t), and the quadrature-phase receiver signal, q(t), from the first mixed signal, x(t), and the second mixed signal, y(t), in accordance with:
i(t)=x(t)
q
⁡
(
t
)
=
1
3
⁢
x
⁡
(
t
)
+
2
3
⁢
y
⁡
(
t
)
.

54 more elements

A method of generating an output signal for transmission in a telecommunications system, the method comprising:

generating an in-phase radio frequency signal by mixing an in-phase baseband signal with a first radio frequency mixer signal;
generating an alternative-phase radio frequency signal by mixing an alternative-phase baseband signal with a second radio frequency mixer signal, wherein a relative phase difference between the in-phase and alternative-phase baseband signals is α radians, wherein |α|≠π/2;
generating an output signal for transmission by combining the in-phase radio frequency signal with the alternative-phase radio frequency signal, wherein the output signal has a frequency, fRF;
and
generating the first and second radio frequency mixer signals by performing:
generating a voltage controlled oscillator (VCO) output signal having a frequency, fVCO, such that
f
VCO
=
(
n
+
1
2
)
·
f
RF
,
wherein n=1,2,3, . . . ;
and
generating the first and second radio frequency mixer signals from the VCO output signal, wherein each of the first and second radio frequency mixer signals has a frequency equal to fRF,
wherein n=1,
the method further comprises a receiver process that comprises:
generating a first mixed signal by mixing a received radio frequency signal with a third radio frequency mixer signal;
generating a second mixed signal by mixing the received radio frequency signal with a fourth radio frequency mixer signal, wherein a relative phase difference between the third and fourth radio frequency mixer signals is α radians;
and
generating, from the first and second mixed signals, an in-phase receiver signal and a quadrature-phase receiver signal, wherein a relative phase difference between the in-phase receiver signal and the quadrature-phase receiver signal is π/2 radians,
and wherein the method further comprises:
generating the in-phase receiver signal, i(t), in accordance with a first function that includes adding the first mixed signal, x(t), and the second mixed signal, y(t);
and
generating the quadrature-phase receiver signal, q(t), in accordance with a second function that includes determining a difference between the first mixed signal, x(t), and the second mixed signal, y(t).

29 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/884,970Filed 7 Jul 2004 · us provisional application
Priority: 16 Jul 2003
Published: US 2005/0036566 A117 Feb 2005
Granted: 20 Jan 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H03K 23/68
With a base or radix other than a power of two: with a base which is a non-integer
H03D 7/165
Multiple-frequency-changing: at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature
H04B 1/30
Circuits: for homodyne or synchrodyne receivers
H03L 7/18
Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop:…