Radar sensors for IoT
XENSIV™ 24GHz and 60GHz radar sensing solutions for industrial and consumer applications – small, accurate, precise
Radar sensors for IoT subcategories
As market leader in radar chips, Infineon offers a wide portfolio of mmWave radar sensors as part of the XENSIV™ sensor family – including Doppler radar as well as FMCW radar systems. This portfolio includes the smallest 24GHz MMIC in the market, as well as the largest and most integrated 24GHz radar transceiver family currently available.
These industrial radar sensors serve industrial and consumer as well as smart home applications. For example, Infineon’s 60GHz radar sensor BGT60TR13C is implemented in the Google Pixel 4 smartphone.
Motion detection with radar sensors offers significant advantages over PIR and other motion sensing technologies
With Infineon’s 24GHz and 60GHz radar portfolio a wide range of application can be covered. For instance, motion detection triggering systems such lighting solutions, automatic doors, camera and security systems, or smart home devices can be developed with Infineon’s radar sensor solutions.
In contrast to other motion detection technologies like PIR, radar technology offers significant advantages. These include smaller system sizes, greater accuracy, and more precise measurements of detected objects. For example, using 24GHz radar sensors for drones improves soft landing and obstacle avoidance. Additionally, IoT radar sensors can also determine the direction of a moving object, speed of an object, distance and, depending on the antenna configuration, even the position of a moving object.
When to use 24GHz or 60GHz radar technology
In the radar 24GHz range, the bandwidth for FMCW radar operations covers 250MHz within the regulated ISM band. In the radar 60GHz regime, an unlicensed ultra-wideband of up to 7GHz can be used for short-range applications. Consequently, 60GHz FMCW IoT radar systems can offer a better resolution and therefore allow additional use cases such as human tracking and segmentation. Even gesture sensing, material classification, or the monitoring of various vital functions (respiration, heartbeat, or even blood pressure) is possible with IoT radar technology due to micro motion detection.
The detection range of radar sensors is larger for lower
operating frequencies as the attenuation of the signal
in free space propagation is lower. Thus, for wide range
target detection 24 GHz sensors perform better than
60 GHz radar sensors.
The range resolution of radar sensors is independent of the
operating frequency itself, however, depends on the avail-
able bandwidth. For both frequency bands EU regulations
limit the available bandwidth. The available ISM bandwidth
for 60 GHz is twice as large as for 24 GHz (500 MHz vs.
250 MHz). Furthermore, there is an ultra-wideband (UWB;
up to 7 GHz) only for 60 GHz radar systems.
Thus, the 60 GHz radar sensor family is able to provide
higher range resolution and ultimately offers higher target resolution.
Infineon provides a variety of 24 GHz as well as 60 GHz radar
sensors. In the IoT family of 60 GHz radar sensors, Infineon
offers sensors with already integrated antennas providing
a less complex system to the user. This much more space-
saving solution is possible due to the inverse linear relation-
ship between frequency and required antenna size.
Our 24 GHz radar family requires external antennas, which
provide more flexibility to the user.
The antenna design is one of the main factors limiting the smallest achievable system size of the radar sensor. Since the space required for the antenna design is indirectly pro-
portional to the operating frequency, 60 GHz radar sensors
minimize the overall system size.
[The system includes the radar transceiver, antennas and supporting circuitry. The numbers given are examples from two of our systems showing the size ratio and might vary for different radar systems.]
With the 24 GHz and 60 GHz radar sensor families,
Infineon offers low power radar solutions to meet the
demands of energy efficiency in the market.
Hidden mounting is a key characteristic of radar sensors because of their ability to sense targets through obstacles like dry walls or plastic cases. However, higher frequency signals of 60 GHz radar sensors suffer more attenuation compared to the lower frequency signals of 24 GHz radar sensors while penetrating a medium. For a better detection through obstacles the use of 24 GHz radars is recommended.
Higher frequency signals of 60 GHz radar sensors suffer more attenuation compared to the lower frequency signals of 24 GHz radar sensors by a penetrated medium. This also applies to the penetration of atmospheric air and is called atmospheric attenuation. Increasing air humidity or even rain increases the atmospheric attenuation significantly. The atmospheric attenuation for 24 GHz radar sensors is lower than for 60 GHz radar sensors, which makes 24 GHz sensors more suitable for use in humid environments.
Both 24 GHz and 60 GHz radar sensors have different advan-
tages and disadvantages when compared to each other.
Thereby, different aspects play a role:
advantages and disadvantages for fundamental physical
reasons.
For the two different frequency families of 24 GHz and
60 GHz there are different regulatory restrictions that
need to be considered in our radar products.
with different grade of integration and features, providing
family specific advantages.
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