Spherical Near-Field Scanner – Characterization of Complex Antenna Structures

Precise Antenna Measurements at Millimeter-Wave Frequencies

Fraunhofer FHR's Spherical Near-Field mmWave Measurement System (SNF-FIX-1.0) provides high-precision measurement capabilities for the characterization of antennas and antenna systems at millimeter-wave frequencies. During spherical near-field measurements, the antenna under test (AUT) remains stationary while a measurement probe scans a defined spherical grid around the AUT.

The system covers a scan range of 360° in phi and 270° in theta with an angular resolution of 0.01°. This enables detailed measurement and experimental characterization of the electromagnetic properties of a wide range of antenna concepts. The infrastructure thus supports the development, optimization, and qualification of advanced antenna and RF systems.

Flexible Positioning and Frequencies up to 500 GHz

A key feature of the system is its extended AUT positioning capability. The stationary AUT mount has been equipped with three additional axes, allowing different devices under test to be precisely aligned at the center of the measurement sphere. This provides reproducible measurement conditions for different antenna geometries and test configurations.

The facility is also prepared for on-chip antenna measurements and can be flexibly adapted to different requirements using interchangeable frequency-band modules. At Fraunhofer FHR, this enables measurements at frequencies of up to 500 GHz. As a result, both conventional antenna structures and highly integrated components relevant to millimeter-wave, terahertz, and RF applications can be characterized.

From Development to Experimental Validation

The spherical near-field scanner supports research and development throughout the entire development process. One of its key applications is the prototyping of antennas and radomes. Even geometrically complex antenna concepts can be developed, simulated, manufactured using technologies such as additive manufacturing, and subsequently validated through measurements.

The close integration of development, simulation, manufacturing, and experimental characterization enables novel concepts to be systematically evaluated and refined. Antenna designs, radiation characteristics, and electromagnetic properties can be assessed, with the measurement results subsequently informing the optimization and further development of future designs. Thanks to its modular architecture, the measurement system can also be adapted to different research questions and future requirements.

Fraunhofer FHR thus provides a versatile research infrastructure for antenna measurements, antenna development, radome characterization, and the development and characterization of highly integrated RF and millimeter-wave systems.