Case Study: Supply and Installation of a Millimetre-Wave Measurement Facility at the University of Birmingham

Measurements for 1 GHz to 330 GHz, Far-Field, SNF and Bistatic Scattering Research

Introduction

Located in the Midlands, the University of Birmingham (UoB) is a leading research institution with a strong focus on science and engineering. Recently obtaining funding from the UK Research and Innovation's Engineering and Physical Sciences Research Council (EPSRC), the University of Birmingham contacted APC Technology Group to develop a 3-in-1 state-of-the-art millimetre-wave measurement facility.

This facility provides advanced measurement capabilities for researchers working on cutting-edge technologies such as 5G/6G wireless communications and high-frequency circuit design.

In this case study, we will examine the scope of the project and what APC were able to deliver with close collaboration with Antenna Systems Solutions (ASYSOL).

Challenge

The UoB recently completed construction of a new building for the School of Engineering which includes an Anechoic Chamber located on the third floor for use by the Communication and Sensing Research Group.

The chamber lacked the hardware (e.g. mechanical stages, RF cables, rotary joints, masts/pedestals etc) and control software required to carry out antenna measurements.

The measurement facility was required to support three primary modes of measurement across the frequency range 1 GHz to 330 GHz:

• Far-field (FF) measurement
• Spherical near-field (SNF) measurement
• Monostatic and bistatic electromagnetic scattering measurement

Solution

Working closely with UoB and ASYSOL, APC Technology Group provided a customised antenna measurement solution to meet the research requirements. Leveraging ASYSOL’s expertise in antenna measurement system design and equipment integration, we supplied a range of mechanical positioners, control components, antennas and RF equipment that enabled the university to perform the following measurements:

• Direct FF measurements of all main antenna parameters across a broad frequency range (1 GHz - 330 GHz). This included a 4-axis positioner for an antenna under test (AUT) and a stationary probe mast with polarisation positioner, corresponding control and RF components, and system operation computer university’s with data acquisition and processing software. Most of the provided components were customised to ensure compatibility with the existing anechoic chamber and providing the precision and automation necessary for the research carried by the university.

• The above setup can easily be reconfigured to perform SNF measurements, by adjusting the distance between the AUT and probe, and using specially designed SNF probes, ASYSOL series ASY-CWG-S/D Corrugated Waveguide Feeds covering 1-18 GHz, and series ASY-CHA-S Conical Horn Antennas covering 18-330 GHz. SNF-FF transformation module was also provided as part of the data processing software.

• Electromagnetic Bistatic Scattering Measurement setup included a custom-designed high-accuracy curved circular track with 190 degrees travel range and 4m radius, which carried another probe mast with polarization positioner. An accurate azimuth positioner holding a foam column for the device under test (DUT), and the stationary probe mast from the FF/SNF setup complement the setup, which also includes a set of pyramidal horn pairs covering 1-330 GHz.

Software solution provided

The university's measurement processes were streamlined with ASYSOL's user-friendly software.

Featuring an intuitive Graphical User Interface, this software package includes all main functionalities required for antenna tests and scattering tests defining various measurement configurations, parameter specification, data acquisition, and advanced processing (including near-field to far-field transformations), while offering data export in several formats and integration with other data processing software packages.

Results

All equipment was integrated with the university's existing anechoic chamber, providing a comprehensive and efficient testing environment. As a result, the university now possesses a 3-in-1 state-of-the-art integrated measurement environment enabling:

All equipment was integrated with the university's existing anechoic chamber, providing a comprehensive and efficient testing environment.

As a result, the university now possesses a 3-in-1state-of-the-art integrated measurement environment enabling:

• Fully automated antenna characterisation through far-field and spherical near-field measurements.
•  Characterisation of bistatic scattering from EM structures (metasurfaces, drones, etc.) and materials.
•  Simultaneous measurement of antennas and intelligent reflecting surfaces, where meaningful de-embedding is not feasible.

The expanded frequency range now allows the university to test antennas up to 330 GHz, opening up new research opportunities in areas such as 5G/6G and satellite communications.

This comprehensive solution fully addressed Birmingham University's need for enhancing its ability to provide an advanced versatile Electromagnetic Characterisation Suite used in industrial and academic research, as well as in development projects, focusing on the issues of accuracy, stability, repeatability and reproducibility of measurements.

• mm-Wave and THz antennas
• Components such as filters, amplifiers, mixers, and diplexers
• Internet of Things (IoT) applications
• Conventional and quantum radar
• Metamaterials, metasurfaces, reconfigurable intelligent surfaces and low-RCS stealth materials
• Materials and device characterisation
• Electromagnetic sensing across domains ranging from materials science to healthcare research
• Terahertz Imaging:  for security (object inspection, weapons and contraband) and medical (oral healthcare, skin cancers);
• Telecommunications (short range exceptionally broad bandwidth communications);​
• Synthetic Aperture Radar sub-THz measurements
• High-resolution multi-dimensional radar for ground, airborne and space-borne applications
• Monostatic, bistatic, multistatic radar operating at multiple frequencies, multiple polarization
• MIMO and Doppler-capable set-up with motion positioners