What is the Vehicular Antenna Test Methodology?

The increased demand for connected vehicles as well as the ongoing deployment of vehicle-to-vehicle communication has revealed that a unified measurement technique for the communication subsystem antenna can bring benefits to the development of vehicular communication systems. A common measurement technique for vehicular antennas (antennas permanently installed on cars) will help ensure that the various regional standards' compliance evaluations are conducted transparently.

5GAA has created a technique to test vehicular antennas for communication and related elements (like GNSS) as an alliance connecting the automotive and telecom industries. A methodology like this could serve as a standard test procedure for antenna communication subsystems. It is also intended to improve the precision of conformity certification methods for these types of vehicles. 5GAA has published these techniques in a white paper titled 'Vehicular Antenna Test Methodology' that can be read here.

The techniques established by 5GAA are to be viewed as a tool for optimizing testing efforts and providing methods to validate antennas based on vehicle form factors and unique characteristics. 5GAA has defined a standardized test method and metrics for external vehicular antennas for different wireless technologies like:

• Vehicular antennas for telecommunications [2G, 3G, 4G, 5G (< 7.125 GHz)]
• Vehicular antennas for direct communication between vehicles and vehicles to road infrastructure (operation in designated ITS frequency spectrum (5.9 GHz range))
• GNSS-Antennas

The defined methodology contains all kinds of principles of measurement setups including the definition of environment/ground materials, type/configuration of measurement equipment and other calibration requirements. It has clearly defined applicable elevation and azimuth ranges and data processing configurations for different types of   measurements like: 

• Passive at the component level (antenna element at its installation location at the vehicle) measured values, for e.g. - realized gain
• Active at the system level (antenna element at its installation location at the vehicle + cabling + onboard control unit) measured values, for e.g. - radiated power, isotropic sensitivity
• Combinations of passive and active resulting values, for e.g. - radiated power, isotropic sensitivity

This established methodology also provides detailed test procedures & processing of measurement results (e.g. grouping, averaging, integral quantities). It also considers uncertainties in measurement results.

5GAA carefully created this test methodology by reviewing existing antenna test procedures/specifications and applied/adopted them wherever possible.

The methods and setups described in 5GAA’s defined test methodology also consider the whole vehicle as the device under test (DUT) for radiated measurements (i.e. passive antenna pattern and active over-the-air (OTA) systems).

Click here to read the Vehicular Antenna Test Methodology defined by 5GAA.