Innovations
in Automotive Radar Testing
Dr. Sherif Ahmed
Director of Innovation Lab
Automotive Solutions
Rohde & Schwarz Automotive at a Glance
Automotive Radar
Supporting chip suppliers,
TIER1s & OEMs for radar
developments from R&D,
quality assurance to
production
Connecting the car to
consumer electronics, the
cloud, infrastructure and
other road users
Guaranteeing compliance
and performing analysis
from physical to
application layer e.g. boot
timing, sleep & wake up
Testing coexistence of
high frequency signals
such as 4G, 5G,
mmWave radar, Wi-Fi and
performing EMC
measurements
Connectivity Automotive Ethernet EMC and EMI
Ensuring radar fitness,
providing target
simulation and testing
signal quality incl.
interference
Testing conformance and
performance of eCall,
V2X, LTE-V, 5G, WLAN
and Bluetooth®
Debugging of bus
systems such as
Automotive Ethernet and
CAN-FD
Providing turnkey
solutions, including RF
chambers, test receivers
and broadband amplifiers
Mar. 2019
Automotive Radar Use Cases
4
Source: http://www.iet.unipi.it/m.greco/esami_lab/Radar/automotive_radar.pdf
Range Resolution vs. Bandwidth
5
Low bandwidth (250 MHz) Wide bandwidth (4 GHz)
75 cm
or
30 in
1 cm
or
0.4 in
Poor range resolution.Am I looking at one or two cars?
Good range resolutionThere are two bikes adjacent to one
another and I can see both of them!
Better Range Resolution Means Better Target Identification
6
Too low of a bandwidth
can make two targets look
like one.
Wide enough bandwidth
clearly shows the right
number of targets
77/79 GHz too high?
7
Source: www.everythingrf.com
High level progress in automotive radars
ı Higher bandwidth
ı Higher pulse rate
ı Wider FOV for close ranges
ı Elevation coverage
ı MIMO/Multistatic
ı Channel coding
ı Complex object tracking
ı .
ı ..
ı …
ı and last but not least: More radars
8
Radar testing
is
crucial
9
How radar function is tested today?
Step 1 simulation
Step 2 table setup
Step 3 target simulator
Step 4 HiL inside vehicle
Step 5 drive test
Step 6 more drive test
Step 7 even more drive tests….
Crucial for testing…Functional Analysis
Signal integrity
FOV Alignment
Enclosure compatibility
10
Crucial for testing…Functional Analysis
Signal integrity
FOV Alignment
Enclosure compatibility
Material Integration Test with R&S®QAR
Technical data
Frequency range 77/79 GHz Band
Spatial resolution 2 mm
Spatial accuracy 1 mm
Dynamic range > 25 dB
Measurement time:
Radome Measurement using the QAR
13
ı Spatially measurement
ı Accuracy less than 1mm
ı Fast measurement
But it is not just the radar, it is the integration too!
14
Source: https://de.wikipedia.org/wiki/Mercedes-Benz_E-
Klasse#/media/File:Mercedes_E-
Klasse_Cabrio_2013_(11210591725).jpgRadome
Radar angular measurement technology
15
𝜑1𝜑2𝜑3𝜑4𝜑5
𝛼
Sampling points
Estimate azimuth / elevation angles from
phase differences / amplitudes at the
receive antennas of the phased array
𝛼 = sin−1𝜆 ∙ ∆𝜑
2𝜋𝑑
∆𝜑
𝑑
𝑑
∆𝜑
𝛼
𝜆
Physical distance between antennas
Phase difference
Angle of arrival
wavelength
Radar angular measurement technology
16
𝜑1𝜑2𝜑3𝜑4𝜑5
𝛼
Phase fronts traveling
towards the radar.
∆𝜑
𝑑
𝑑
∆𝜑
𝛼
𝜆
Physical distance between antennas
Phase difference
Angle of arrival
wavelength
𝛼 = sin−1𝜆 ∙ ∆𝜑
2𝜋𝑑
∆𝜑1 ≠ ∆𝜑2 ≠ ∆𝜑3 ≠ ∆𝜑4 ≠ ∆𝜑5
Phase estimation is wrong
Radar angular measurement technology
17
𝛼
Phase fronts traveling
towards the radar.
∆𝜑l The radar is slightly moved.
l The distance between the antennas is
changed.
l Another algorithm is used for angle of
arrival estimation during post processing.
Or, more general, if:
l Another radar / radome combination is
used.
𝜑1𝜑2𝜑3𝜑4𝜑5
𝑑
Measuring the angle error does not lead
to useful results, if:
An alternative method has to be used.
Rain Wet
Environmental conditions
Dry
Car bumper
Signal path and
FOV cross the
same surface of the
bumper
Radar FOV
Reference reflector
21
Diffuse reflectors
Absorber Backplane
Example for reference reflector
Car bumper
In production
Crucial for testing…Functional Analysis
Signal integrity
FOV Alignment
Enclosure compatibility
23
Radar positioning (Einbaulage)
24
Video
Radar FOV clearance
25
Source: LINK
www.bosch-mobility-solutions.de
Example
for
illustration
purpose
only
Sensor orientation is critical, especially when
mounted separately behind emblem.
https://www.bosch-mobility-solutions.de/de/produkte-und-services/pkw-und-leichte-nutzfahrzeuge/fahrerassistenzsysteme/vorausschauendes-notbremssystem/mittelbereichsradarsensor-(mrr)/
Radar FOV clearance
26
Sensor orientation is critical, especially when
mounted separately behind emblem.
End-of-line testing
Examination of Radar alignement
27
Q
A
R
Car on floor
05-Apr-19 28
Phase interferometry is
used for precise detection
of surface orientation.
QAR measurement
3D Beam Overlay
29
Example Side View Example 3D View
Crucial for testing…Functional Analysis
Signal integrity
FOV Alignment
Enclosure compatibility
30
Interference Tests of RADAR Signals
radar echos interfering signal
present
no interferenceSNR
Crucial for testing…Functional Analysis
Signal integrity
FOV Alignment
Enclosure compatibility
32
Functional test with target simulation
R&S©ATS1500
Shielded RF Chamber
R&S©AREG
Thanks
for
your
attention!