Automotive radar transmitter architecture

• US 8,791,854 B2
• Filed: 10/10/2011
• Issued: 07/29/2014
• Est. Priority Date: 10/10/2011
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Forstner, Johann Peter, Gerlach, Udo
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US13/269,690
• Publication Number:
  US 20130088383A1
• Time in Patent Office: 1,023 Days
• Field of Search: 342/175, 342/81, 342/154, 342157-158, 342/368, 342371-374
• US Class Current: 342/81
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 7/02 of systems according to group G01S13/00
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems
• CPC Class Codes: G01S 7/358 using I/Q processing
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/0617 for beam forming

Abstract

One embodiment of the present invention relates to a radar transmitter comprised within a single integrated chip substrate, which is capable of continuous beam steering of a transmitted radar beam as well as an option to change the physical position of the origin of the transmit radar beam. The radar transmitter has a signal generator that generates an RF signal. The RF signal is provided to a plurality of independent transmission chains, which contain independently operated vector modulators configured to introduce an individual phase adjustment to the high frequency input signal to generate separate RF output signals. A control unit is configured to selectively activate a subset of (e.g., two or more) the independent transmission chains. By activating the subset of independent transmission chains to generate RF output signals with separate phases, a beam steering functionality is enabled. Furthermore, the subset defines a changeable position of the transmitted radar beam.

Claims

1. A digital beam forming (DBF) radar transmitter, comprising:

a signal generator configured to generate a radio frequency (RF) input signal at an output node;

a plurality of independent transmission chains coupled to the output node and configured to receive the RF input signal, wherein respective independent transmission chains comprise a vector modulator configured to independently introduce an amplitude adjustment or a phase adjustment to the RF input signal; and

a control unit configured to independently activate and deactivate the plurality of independent transmission chains, such that a subset of the plurality of transmission chains is activated to concurrently operate to generate a transmitted radar beam.

2. The radar transmitter of claim 1, wherein the DBF radar transmitter is comprised within a single integrated chip substrate.

3. The radar transmitter of claim 2, wherein the single integrated chip substrate comprises a silicon substrate.

4. The radar transmitter of claim 1, wherein the subset of the plurality of independent transmission chains comprises two or more of the plurality of independent transmission chains.

5. The radar transmitter of claim 1, further comprising:

a plurality of switching elements configured to selectively active and deactivate the plurality of transmission chains, based upon a control signal received from the control unit, in a manner that moves a location of the origin of the transmitted radar beam.

6. The radar transmitter of claim 1, wherein the vector modulator comprises:

a controller configured to generate one or more control signals; and

one or more IQ mixers configured to introduce the amplitude adjustment or the phase adjustment to the RF input signal based upon the one or more control signals.

7. The radar transmitter of claim 1, wherein the plurality of independent transmission chains comprise:

a first transmission chain comprising a first vector modulator configured to introduce a first amplitude adjustment or a first phase adjustment into the RF input signal; and

a second transmission chain comprising a second vector modulator configured to introduce a second amplitude adjustment, different than the first amplitude adjustment, or a second phase adjustment, different than the first phase adjustment, into the RF input signal.

8. The radar transmitter of claim 7, wherein the first and second vector modulators respectively comprise:

a signal splitter configured to separate the RF input signal into an in-phase RF input signal and a quadrature phase RF input signal;

a controller configured to generate an in-phase control signal and a quadrature phase control signal having a 90°

phase shift therebetween;

a first IQ mixer configured to mix the in-phase RF input signal with the in-phase control signal to generate a modulated in-phase signal;

a second mixer configured to mix the quadrature phase RF input signal with the quadrature phase control signal to generate a modulated quadrature phase signal; and

an adder configured to combine the modulated in-phase signal and the modulated quadrature phase signal to generate an RF output signal.

9. The radar transmitter of claim 1, wherein the plurality of independent transmission chains respectively comprise:

a power amplifier configured to adjust the amplitude of an RF output signal generated by the vector modulator.

10. The radar transmitter of claim 9, further comprising:

a power supply configured to selectively provide a bias voltage to the power amplifier, wherein each independent transmission chain is activated or deactivated by controlling the bias to voltage provided to the power amplifier.

11. A digital beam forming (DBF) radar transmitter, comprising:

a single integrated chip comprising;

a signal generator configured to generate a radio frequency (RF) input signal;

a plurality of independent transmission chains configured to receive the RF input signal, wherein respective independent transmission chains comprise;

one or more IQ mixers configured to introduce an amplitude adjustment or a phase adjustment to the RF input signal;

a power amplifier configured to adjust the amplitude of an RF output signal generated by the vector modulator;

a power supply configured to selectively provide a bias voltage to the power amplifier, wherein each independent transmission chain is activated or deactivated by controlling the bias to voltage provided to the power amplifier; and

a control unit configured to independently activate and deactivate the plurality of independent transmission chains, such that a subset of the plurality of independent transmission chains are concurrently activated to generate a transmitted radar beam having a beam steering functionality;

wherein the subset of the plurality of independent transmission chains define a location of an origin of the transmitted radar beam.

12. The DBF radar transmitter of claim 11, further comprising:

a plurality of switching elements configured to selectively active and deactivate the plurality of transmission chains, based upon a control signal received from the control unit, in a manner that moves a location of the origin of the transmitted radar beam.

13. The DBF radar transmitter of claim 11, wherein the plurality of independent transmission chains comprise:

a first transmission chain comprising a first vector modulator configured to introduce a first amplitude adjustment or a first phase adjustment into the RF input signal; and

a second transmission chain comprising a second vector modulator configured to introduce a second amplitude adjustment, different than the first amplitude adjustment, or a second phase adjustment, different than the first phase adjustment, into the RF input signal.

14. The DBF radar transmitter of claim 13, wherein the first vector modulator and the second vector modulator, respectively comprise:

a signal splitter configured to separate the RF input signal into an in-phase RF input signal and a quadrature phase RF input signal;

a controller configured to generate an in-phase control signal and a quadrature phase control signal having a 90°

phase offset therebetween;

a first IQ mixer configured to mix the in-phase RF input signal with the in-phase control signal to generate a modulated in-phase signal;

a second mixer configured to mix the quadrature phase RF input signal with the quadrature phase control signal to generate a modulated quadrature phase signal; and

an adder configured to combine the modulated in-phase signal and the modulated quadrature phase signal to generate an RF output signal.

15. A method for generating a transmitted radar beam, comprising:

generating a radio frequency (RF) input signal;

providing the RF input signal to plurality of transmission chains, wherein respective transmission chains have a vector modulator;

activating a subset of the plurality of transmission chains to define a location of a transmitted radar beam,

introducing separate phase adjustments to the RF input signal provided to the subset of the plurality of transmission chains to generate a plurality of RF output signals by;

operating a first activated transmission chain to introduce a first amplitude adjustment or a first phase adjustment into the RF input signal; and

operating a second activated transmission chain to introduce a second amplitude adjustment, different than the first amplitude adjustment, or a second phase adjustment, different than the first phase adjustment, into the RF input signal; and

transmitting the plurality of RF output signals from antennas corresponding to the subset of the plurality of transmission chains.

16. The method of claim 15, wherein introducing separate phase adjustments, comprises

separating the RF input signal into an in-phase RF input signal and a quadrature phase RF input signal;

generating an in-phase control signal and a quadrature phase control signal having a 90°

phase offset therebetween;

mixing the in-phase RF input signal with the in-phase control signal to generate a modulated in-phase signal;

mixing the quadrature phase RF input signal with the quadrature phase control signal to generate a modulated quadrature phase signal; and

combining the modulated in-phase signal and the modulated quadrature phase signal to generate an RF output signal.

17. The method of claim 15, wherein activating a subset of the plurality of transmission chains, comprises:

selectively providing a bias voltage to power amplifiers located within respective transmission chains.