Radar sensors for IoT

24 GHzvs.60 GHz

Detection range

Up to 100 m

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.

Up to 10 m

Range resolution

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.

Up to x28 related to 24 GHz

Integrated antennas

No

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.

Yes

System size

~625 mm ²

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.]

~125 mm ²

Power consumption

<1 mW possible

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.

<1 mW possible

Detection through obstacles

Good penetration

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.

Limited penetration

Enviromental robustness

Unsusceptible

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.

Vulnerable

Physical aspect

Regulatory aspect

Product aspect

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:

›Physical aspects:

The 24 GHz and 60 GHz radar sensors have different
   advantages and disadvantages for fundamental physical
   reasons.

›Regulatory aspects:
   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.

›Product aspects:

Infineon offers a wide variety of sensors for both families
   with different grade of integration and features, providing
   family specific advantages.