Microwave Journal

Executive Interview: Lars Jacob Foged, MVG’s Scientific Director

October 30, 2016

What technical problems are antenna test and measurement engineers facing today

Today, the antenna test and measurement community is going through very interesting changes. The antenna, and associated tests were until recently, often perceived as a necessary evil to be completed in a final stage before a new wireless product launch. Testing has been oversimplified and reduced to simple performance parameters such as efficiency, using non-anechoic methods, thus neglecting to properly characterize the radiating properties of the antenna. The days in which software upgrades where acceptable solutions to antenna problems in the final product are over. 

Consumers are now fully aware of the antenna component of their wireless devices and they have grown accustomed to expect high performance while maintaining safety of use through limited user exposure. Future consumer and communication products will integrate more antennas. The awareness that the antenna performance is influenced by its local environment and must be tested as a system component is growing. We are noticing that test and measurements are becoming integral parts of the device development cycle. Other important changes are in antenna system test that was previously performed as conducted experiments, are now being done as OTA measurements.   

There are still some technical problems need to be overcome to complete this transformation. New requirements are put on test equipment that is no just longer “pass-fail” but provide sufficient information as part of performance trade-offs in all antenna design stages. A closer integration and data exchange of the antenna test system with external test equipment and standard computational software is also needed.         

As an expert in antenna test and measurement, how does MVG solve these technical problems?

The challenges in developing fast and reliable test and measurement solutions for the future can only be addressed through a continued R&D effort, strong collaboration with commercial clients and academic institutions, and a high level of activity in international standardization groups.

How do the emerging antenna technologies and applications such as antennas for 5G base stations and handsets, IoT devices, massive MIMO, commercial phased-arrays, 3D printing, metamaterials, etc., affect the methods and techniques of antenna test and measurement?

Emerging antenna technologies and materials have an impact on innovation and development in the antenna test and measurement field. However, the strongest driver for test and measurements are new applications. Technologies such as 3D printing, flexible, wearable antennas and antennas with metamaterials do not fundamentally change the testing and measurements in the same way as new applications based on these technologies.

One example is wearable antennas for body area networks that must be tested on a person or mannequin. MVG has a long experience on person/mannequin measurements based on fast multi-probe system technology. The possibility to test simultaneously for performance and safety parameters such a specific absorption rate (SAR) is being developed.

Antennas for 5G enabled devices such as base station and handset, antennas for IoT devices, massive MIMO antennas including phased arrays are likely to change the measurement scenario as used today. One example is on-wafer measurements of integrated antennas. Other likely test scenarios include OTA testing at millimeter wave bands for both user terminals and base-stations.

What test and measurement solutions can MVG provide for the these applications

The increasing demand for on-wafer measurements at millimeter frequencies has been anticipated by MVG with the release of MicroLab, a portable 20-110 GHz measurement system, designed also to meet the needs of integrated antennas not easily accessible by standard means.  MVG already performs OTA testing at millimeter wave bands for 5G applications with selected customers. The imminent needs for fast testing of 5G enabled antenna systems up to 42 GHz has been anticipated by MVG with the release of new products coming soon. Based on fast multi-probe technology, MVG has released its fast production line testing system for BTS antennas, capable of detecting production errors.

Which standards for antenna test and measurement are in development now? What’s the role of MVG in the international antenna test and measurement standards process?

MVG is very active in international standardization and fully support my activities as secretary of the IEEE antenna standards committee since 2004. Standardized testing of devices is equally important for development, verification and type approval activities. The scope of standardization is to guarantee that widely accepted and fully validated test methods are available so that test results can be reproduced independently for the test system implementation. In recent years, MVG has contributed to standardization activities such as IEEE std 145-2013 “Standard for Definitions of Terms for Antennas”, IEEE std 1720-2012 “Recommended Practice for Near-Field Antenna Measurements” and the ongoing revision of IEEE std 149 “Standard Test Procedures for Antennas”. MVG is also contributing to the continued development of the IEC 62209 standard(s) on human exposure to electromagnetic fields. Finally, MVG is active in 3GPP and CTIA standardization bodies. In 3GPPP, MVG is contributing to the “Active Antenna Stations” (AAS) Over-the-air (OTA) testing, “Over-The-Air MIMO” (MIMO-OTA) testing and “New Radio” (NR) 5G studies working groups while, MVG has been the key company for the release of the first 2x2 MIMO OTA test plan at CTIA. MVG is also active in CCSA (Chinese Communications Standard Association) for MIMO OTA testing and BS (Base Station) antenna measurement working groups.

What antenna test and measurement patents does MVG own? What competitive advantages can these patents bring to MVG?

MVG is protecting its unique knowledge with international patents and as such has a large portfolio of patents on key technologies. It is well known that patents are meant to give developer of new technology such as MVG a “grace-period” in which competitors cannot copy proprietary technology. Unfortunately, patents are not a guarantee that technology is not copied by others. MVG is increasing its spending to defend its patent rights, particularly in China. As an engineer, I find it unfortunate that even my peers do not respect engineering achievements. It is beneficial in some cases not to inform the community about achievements in form of a patent that disclose technological details. An alternative is to document achievements to establish parenthood and defend the technology against future patents by others. This is sometimes useful in areas in which the MVG technological edge is years in advancement of others.

What R&D projects for antenna test and measurement in progress in MVG?

MVG has a very active R&D program and spend close to 10% of its revenue on long and short term projects. Some of these projects are strategic and aim at using the MVG fast multi-probe technology in other fields such and medical and material testing. Some projects are public, such as developments of standards or projects with high degree of collaboration with universities and research institutions.

Can MVG’s existing antenna test products and solutions meet all the testing requirements of all existing antennas? Whatever the frequency, power, size and form factor of an antenna are, and what scenarios are: on-site, in a production line or in a laboratory.

MVG is in a unique position to respond to future antenna test challenges as the world’s leading provider of classical single-probe and multi-probe measurements solutions. This includes fast testing and OTA measurements but also classical NF and FF testing solutions at millimeter wave bands. A major effort is required by the entire industry and MVG in particular to define fast, reliable and very importantly, repeatable testing methodology for OTA testing at millimeter wave bands for both user terminals and base-stations.

Variable testing scenarios, different from the controlled laboratory environment is an important question that we will see (much) more in the future. MVG is unique in having standard test solutions today, for fast production testing of devices such as base-stations, radomes and up to full satellite testing systems. It is also unique, for the investment in standard on-site or in-situ measurement systems. MVG is collaborating with its clients to make sure we have solutions for the measurement needs of tomorrow.

What are some of the current trends in antenna test and measurement?

The trend we see today is towards increased use of near field scanning methodology for complete antenna characterization. Near-field methods are generally, considered more accurate and less expensive that traditional far-field methods. Recent advances in measurement post-processing give access to a wide spectrum of information on antenna performance that was not available before. There will be several significant developments in antenna test and measurements methodology in the near future. The trends regard: Development tools for antenna design and installation/positioning on structures using measurements, intelligent production testing of complex devices such as 5G enabled terminals / base-stations and increased use of in-situ testing.

An increased need for very fast production testing is expected for very complex devices, such as terminals and base-stations for the upcoming 5G. Measurement speed and intelligent post-processing pinpointing errors for recovery action will be the drivers in this development.

While the development of black box electrical representation of microwave components by S-parameters have revolutionized the design of integrated circuits several years ago, the development of an equivalent box representation of devices radiating into 3D space, such as antennas, has just recently been completed. This development is expected to have a profound impact on industrial antenna development cycles. MVG is working closely with leaders in numerical simulation community to this end. A direct link from MVG measurements software has been developed that allow to import the measured antenna into the numerical simulation tools to evaluate integrated performances such as antennas on structures, phased array performance from measurements on the single antenna element.

A further development is to use measurements and simulation in conjunction with rapid prototyping tools, such as 3D machining, to create very efficient, closed loop, antenna prototyping environment with design, prototyping and measurement in one integrated environment.

Exciting moments for MVG - based on our heritage, we are fully committed to defining the test and measurement equipment of tomorrow and satisfying the new needs of the emerging antenna technologies and applications.