Radar device with phase noise estimation

Patent metadata

Field	Value
Publication number	US-10670698-B2
Application number	US-201615358363-A
Country	US
Kind code	B2
Filing date	Nov 22, 2016
Priority date	Nov 30, 2015
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A method for estimating phase noise of an RF oscillator signal in a frequency-modulated continuous-wave (FMCW) radar system and related radar devices are provided. The method includes applying the RF oscillator signal to an artificial radar target composed of circuitry, which applies a delay and a gain to the RF oscillator signal, to generate an RF radar signal. Furthermore, the method includes down-converting the RF radar signal received from the artificial radar target from an RF frequency band to a base band, digitizing the down-converted RF radar signal to generate a digital radar signal, and calculating a decorrelated phase noise signal from the digital radar signal. A power spectral density of the decorrelated phase noise is then calculated from the decorrelated phase noise signal, and the power spectral density of the decorrelated phase noise is converted into a power spectral density of the phase noise of an RF oscillator signal.

First claim

What is claimed is:

1. A method for estimating phase noise of radio frequency (RF) oscillator signal in a frequency-modulated continuous-wave (FMCW) radar system, the method comprising:
applying the RF oscillator signal to an artificial radar target composed of circuitry, which applies a delay and a gain to the RF oscillator signal, to generate a RF radar signal;
down-converting the RF radar signal received from the artificial radar target from a RF frequency band to a base band;
digitizing the down-converted RF radar signal to generate a digital radar signal;
calculating a decorrelated phase noise signal from the digital radar signal;
calculating a power spectral density of the decorrelated phase noise from the decorrelated phase noise signal; and
converting the power spectral density of the decorrelated phase noise into a power spectral density of the phase noise of the RF oscillator signal.

2. The method of claim 1 , wherein calculating the decorrelated phase noise signal from the digital radar signal is done in accordance with the equation:

Δφ
O

⁡

[
n
]

≈

A
O

2

·

cos
⁡

(

2
⁢
π
⁢

⁢

f
BO

⁢

nT
A

+

Φ
O

)

-

y
O

⁡

[
n
]

A
2

A
O

2

·

sin
⁡

(

2
⁢
π
⁢

⁢

f
BO

⁢

nT
A

+

Φ
O

)

,

wherein n is a time index, T A is a sampling period, Δφ O is the decorrelated phase noise signal, y O [n] is digital radar signal, A is the amplitude of the RF oscillator signal, A O is the gain of the artificial radar target, f BO is a beat frequency and Φ O is a phase offset.

3. The method of claim 1 , wherein converting power spectral density of the decorrelated phase noise into the power spectral density of the phase noise of an RF oscillator signal is done in accordance with the equation:

S

φ
,
φ

⁡

(
f
)

=

S

Δφ
O

,

Δφ
O

⁡

(
f
)

2
⁢

(

1
-

cos
⁡

(

2
⁢
π
⁢

⁢
f
⁢

⁢

τ
O

)

)

,

wherein S φ,φ (f) is the power spectral density of the phase noise, S Δφ O ,Δφ O (f) is the power spectral density of the decorrelated phase noise and T O is the delay of the artificial radar target.

4. The method of claim 1 , wherein the RF oscillator signal is supplied to at least one antenna to be radiated as electromagnetic radar signal.

5. The method of claim 1 , wherein the RF oscillator signal is a sequence of chi

Assignees

• Infineon Technologies Ag

Inventors

• Melzer Alexander
• Huemer Mario
• Onic Alexander
• Starzer Florian
• Stuhlberger Rainer

Classifications

• G01S2007/4065

  Physics · mapped topic

• G01S13/931

  of land vehicles · CPC title

• G01S13/343

  using sawtooth modulation · CPC title

• G01S7/038

  Feedthrough nulling circuits · CPC title

• G01S7/4008

  of transmitters · CPC title