Apparatus and a method for handling a received signal, and a mixer unit

Patent metadata

Field	Value
Publication number	US-9312898-B2
Application number	US-201414261960-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	May 2, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

An apparatus for handling a received signal comprises a reception device, a mixer unit and a compensating unit. The reception unit can receive a received signal. The received signal has at least one signal component at a first frequency. Furthermore, the mixer unit can combine the received signal and a compensating signal using at least one active element in order to obtain a compensated received signal. In addition, the mixer unit can produce a mixer output signal on the basis of the compensated received signal and a local oscillator signal. In this case, the mixer output signal has a signal component, corresponding to the at least one signal component of the received signal, at a second frequency. The first frequency is higher than the second frequency. Furthermore, the compensating unit can produce the compensating signal on the basis of an analysis of the mixer output signal, as a result of which it is possible for noise components that the mixer output signal contains to be reduced on the basis of the compensating signal.

First claim

The invention claimed is:

1. An apparatus for handling a received signal, comprising:
a reception device configured to receive a received signal, wherein the received signal has at least one signal component at a first frequency;
a mixer unit configured to combine the received signal and a compensating signal using at least one active element in order to obtain a compensated received signal, and to produce a mixer output signal on the basis of the compensated received signal and a local oscillator signal,
wherein the mixer output signal has a signal component, corresponding to the at least one signal component of the received signal, at a second frequency, the first frequency being higher than the second frequency;
a compensating unit configured to produce the compensating signal on the basis of an analysis of the mixer output signal, as a result of which noise components in the mixer output signal can be reduced based on the compensating signal,
wherein the mixer unit comprises a mixer to mix the compensated received signal with the local oscillator signal to produce the mixer output signal; and
a phase shifter configured to provide the local oscillator signal in temporally successive periods for the mixer unit with different phase shifts, as a result of which the mixer output signal has temporally successive portions with different phase shifts, wherein the compensating unit is configured to produce the compensating signal based on at least two portions of the mixer output signal with different phase shifts.

2. The apparatus as claimed in claim 1 , wherein the compensating unit is configured to produce a control signal for the phase shifter, as a result of which a chronology of different phase shifts can be controlled by the control signal.

3. The apparatus as claimed in claim 1 , wherein the phase shift is alternately +90° and −90°.

4. The apparatus as claimed in claim 1 , wherein the phase shift is effected at a frequency that is lower than one thousandth of a local oscillator frequency of the local oscillator signal.

5. The apparatus as claimed in claim 1 , wherein the mixer unit comprises a second mixer configured to produce a second mixer output signal on the basis of the received signal, a local oscillator signal that is phase-shifted with respect to the local oscillator signal used by the first mixer and the compensating signal, wherein the second mixer output signal has a signal component corresponding to the at least one signal component of the received signal, at the second frequency, wherein the compensating unit is configured to produce the compensating signal based on the first and second mixer output signals.

6. An apparatus for handling a received signal, comprising:
a reception device configured to receive a received signal, wherein the received signal has at least one signal component at a first frequency;
a mixer unit configured to combine the received signal and a compensating signal using at least one active element in order to obtain a compensated received signal, and to produce a mixer output signal on the basis of the compensated received signal and a local oscillator signal,
wherein the mixer output signal has a signal component, corresponding to the at least one signal component of the received signal, at a second frequency, the first frequency being higher than the second frequency;
a compensating unit configured to produce the compensating signal on the basis of an analysis of the mixer output signal, as a result of which noise components in the mixer output signal can be reduced based on the compensating signal,
wherein the mixer unit comprises a mixer to mix the compensated received signal with the local oscillator signal to produce the mixer output signal, and
wherein the compensating unit is configured to calculate an absolute value for a complex number during the analysis of the mixer output signal, wherein the complex number has a real portion based on a first phase shift for the local oscillator signal, and an imaginary portion based on a second phase shift for the local oscillator signal, wherein the compensating unit is configured to produce the compensating signal, as a result of which the absolute value of the complex number can be reduced.

7. The apparatus as claimed in claim 6 , wherein the real portion is based on a DC voltage component of the mixer output signal in the case of the first phase shift for the local oscillator signal and the imaginary portion is based on a DC voltage component of the mixer output signal in the case of the second phase shift for the local oscillator signal.

8. An apparatus for handling a received signal, comprising:
a reception device configured to receive a received signal, wherein the received signal has at least one signal component at a first frequency;
a mixer unit configured to combine the received signal and a compensating signal using at least one active element in order to obtain a compensated received signal, and to produce a mixer output signal on the basis of the compensated received signal and a local oscillator signal,
wherein the mixer output signal has a signal component, corresponding to the at least one signal component of the received signal, at a second frequency, the first frequency being higher than the second frequency; and
a compensating unit configured to produce the compensating signal on the basis of an analysis of the mixer output signal, as a result of which noise components in the mixer output signal can be reduced based on the compensating signal,
wherein the received signal and the compensating signal are voltage signals,
wherein the mixer unit comprises a mixer, a first transconductance stage and a second transconductance stage,
wherein the first transconductance stage is configured to convert the received signal into a first current signal,
wherein the second transconductance stage is configured to convert the compensating signal into a second current signal,
wherein the mixer unit is configured to sum the first current signal and the second current signal to obtain a summed current signal, and
wherein the mixer is configured to mix the summed current signal with the local oscillator signal to obtain the mixer output signal.

9. The apparatus as claimed in claim 8 , wherein the at least one active element is a transistor.

10. The apparatus as claimed in claim 8 , wherein the compensating unit is configured to provide the compensating signal iteratively based on repeated analysis of the mixer output signal.

11. The apparatus as claimed in claim 8 , wherein the compensating unit is configured to produce the compensating signal based on a local oscillator signal that is modified based on the analysis of the mixer output signal.

12. The apparatus as claimed in claim 11 , wherein the compensating unit has an in-phase/quadrature phase modulator configured to modify the local oscillator signal based on the analysis of the mixer output signal to obtain the compensating signal.

13. The apparatus claimed in claim 8 , wherein each of the two transconductance stages has a current source configured to be switched by a transistor to produce the relevant current signal when the received signal or the compensating signal is applied to a control connection of the transistor.

14. The apparatus as claimed in claim 8 , wherein the mixer unit is a differential mixer unit.

15. A homodyne receiver comprising the apparatus claimed in claim 8 .

16. A radar system comprising a transmission unit and an apparatus as claimed in claim 8 , wherein the transmission unit is configured to send a transmission si

Assignees

• Infineon Technologies Ag

Inventors

• Wagner Christoph

Classifications

• H04B15/04

  the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder · CPC title

• G01S7/03

  Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver · CPC title

• H04B1/12 Primary

  Neutralising, balancing, or compensation arrangements · CPC title

• G01S7/023 Primary

  Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36) · CPC title