VNA-Wheel Sensor - Multifunctional rf-wheel-sensor


Ref.-No. 4333

In today's passenger cars, a large number of sensors are installed which monitor the vehicle condition. For example, since 01.11.2014, all new cars have to be fitted with tire pressure sensors according to the EU regulation. The monitoring of the springs is another very important measuring parameter. This sensor electronics weighs about 40 g and is attached to the wheel housing.

The so-called VNA wheel sensor can be used for the following contactless measurements: tire pressure, tire moisture, wheel speed, spring depth, suspension speed, steering angle and foreign body detection.

The VNA wheel sensor consists of a permissible transmitter for a broadband microwave signal (in the microwave range), a vector network analyzer (VNA) and an evaluation unit.

The entire system operates autonomously and supplies the conditioned measurement points to the CAN bus. By means of a simple measuring structure, for example a rubber hose on the rim, the tire pressure can be determined via the reflected microwave signal.

In addition to the tire pressure, the spring depth and speed can also be measured without additional installations. A specially coated rubber hose also allows the measurement of the steering angle and the rotational frequency of the wheel (and thus also the speed). The detection of (metallic) foreign bodies in the tire is also possible.

Keywords: Hochfrequenz, Mikrowelle, Radsensor, Reifendruck, Federtiefe, Lenkeinschlag, Feuchtigkeit, Sensor, Automotive, Radio frequency, microwave, wheel sensor, tire pressure, spring depth, steering angle, moisture, sensor, automotive

Commercial Application

The VNA wheel sensor is mounted in the wheel housing and operates independently fom the tire or the rim. Only a simple and cost-effective measuring structure must be applied to the rim. Since the VNA wheel sensor fulfills several sensor functions, it can also replace several sensors in the motor vehicle. This saves on the one hand weight, on the other hand the costs for the sensors themselves and their installation are significantly reduced.

Current Status  

A German and an international patent application were filed, international applications are still possible.

In the name of the University of Applied Sciences Aachen, we offer interested companies the opportunity to license and further develop the Technology.


  • Simple construction
  • Robust
  • Durable
  • Not mounted on tire or rim
  • Measurement of several parameters possible
  • Can replace several other sensors


PROvendis GmbH · Schloßstr. 11 – 15
D – 45468 Mülheim an der Ruhr
T +49 (0)208 94105-0 ·