Microwave Technology:
Directions and Measurement Requirements for the 21st Century

Dennis Friday
Boulder, CO

The Electromagnetic Fields Division of the National Institute of Standards and Technology’s (NIST) Electronics and Electrical Engineering Laboratory is hosting a workshop that will review NIST support for the RF/microwave industry. This workshop is a unique opportunity for industry to provide guidance for NIST program planning activities.

The primary purpose of this gathering is to create a forum wherein members of a broad cross section of the RF and microwave industry can present their visions of the future of microwave technology and the corresponding measurement needs in the context of the rapid technological advances and global economic changes currently taking place. The product will be a prioritized list of the measurement requirements that will best enhance industry competitiveness over the next five to 10 years.

The workshop’s secondary purpose is to critically assess NIST’s role in supporting present and future measurement traceability requirements for this technology and to explore new and potentially more efficient alternatives for establishing national measurement compatibility for microwave products and systems in the 21st century. Participants will evaluate the effectiveness of current measurement services, explore alternative methods for ensuring measurement traceability and new modes for technical support to industry, and receive the opportunity to communicate special needs and concerns. The results of this workshop will provide guidance for planning and, if necessary, restructuring microwave measurement service programs.

The benefit to NIST is timely information from our customers that will enable us to enhance national competitiveness by implementing the most efficient processes for national measurement compliance, allocating limited resources to address the highest priority industry needs and broadening the traditional scope of measurement support to industry. Possible examples of broader measurement support include the development of recommended test and measurement methods, and guidelines for industrial uncertainty analyses.

Technology Focus

The workshop will focus on metrology that supports the characterization of guided-wave components, devices and systems (active as well as passive), including the traditional coaxial and waveguide transmission line-based NIST programs relating to impedance, scattering parameters, power, thermal noise, attenuation and RF voltage. The future of this technology is of special interest. Also included are NIST programs for MMICs and on-wafer measurements and standards, and other measurement issues related to integrated microwave technology. The measurement of the electromagnetic properties of thin-film and bulk materials at microwave frequencies is also relevant, as are newer NIST programs in broadband and nonlinear circuit analysis, measurement of passive intermodulation products and measurements for wireless systems performance. Among the topics not included in the scope of this workshop are NIST programs in antenna characterization, standard electromagnetic (EM) fields and EM compatibility. NIST also is open to suggestions for new services and programs that are not presently provided but fall within these broad boundaries.


In recent years, systematic efforts to forecast the future of microwave technology and its long-term measurement needs have not been made while major technology roadmaps for other technology crosscuts have been developed. The immediate challenges and new measurement requirements of integrated technologies are receiving substantial attention in technical symposia, but forward-looking technology forecasts do not exist. Coaxial and waveguide technologies, which have experienced only incremental advances in recent years, remain critical to the commercial infrastructure and also suffer from a lack of systematic planning.

The major shift in the primary microwave customer base from defense and aerospace companies to commercial applications companies has effectively ended the primary oversight role that the Department of Defense (DoD) assumed with respect to long-term planning for future microwave metrology needs. The DoD role ultimately served the commercial microwave community by ensuring (through planning and funding) that basic NIST measurement standards were developed and measurement services were available when needed by the applications technology. While this process did not address every need, it had a significant impact.

Historically, when industrial needs were not being met, task forces were formed to address the issue and lobby for NIST support. The Committee to Promote National Microwave Standards and subcommittees of the National Conference of Standards Laboratories are examples of organizations that have formed task forces to identify deficiencies in microwave measurement capabilities at NIST. These efforts have addressed existing gaps in NIST measurement capabilities as compared to the prediction of future needs. The deficiencies often resulted from a lack of sufficient prior knowledge of an approaching need. A forward-looking process that anticipates needs is required.

Workshop Tasks

Forecasting Technology
Workshop participants will be asked to provide assessments of the most likely directions that the microwave technology underpinning their business or applications area will take during the trans-millennium period — the next five to 10 years. Of particular interest are the trends and emerging requirements for conventional coaxial lines; waveguides; and general components, devices and systems with connector or flange interfaces. Integrated microwave technology also will be addressed as well as its effects on the more traditional technologies. NIST intends to reach beyond traditional calibration laboratory customers to include component, device and applications engineers and managers to develop a more comprehensive vision of the future.

Prioritizing Measurement Needs
The technology forecasts will provide a basis for predicting future measurement needs. The workshop participants, including NIST staff, will evaluate the technologies and determine measurement requirements. Lists of these requirements will be produced and industrial participants will be asked to vote on their priorities. These requirements may include new NIST measurement capabilities (parameters, ranges and/or uncertainties), standard reference artifacts, NIST-approved test methods or any innovative new mode of support determined by industry. The results of the voting process will be presented and discussed, adjusted if necessary and endorsed by the participants. It then will be determined how NIST can best support these requirements.

Assessing Measurement Services
A fundamental review of existing practices directed toward national measurement assurance for microwave parameters is required. Workshop participants will be asked to think outside the boundaries to propose new and innovative alternatives to the present process. The dynamics of the evolution of the microwave measurement process from its inception during World War II into the next century may be changing. Industry and NIST may have similar capabilities in some cases, yet the requirement for measurement verification and several questions remain. Are we approaching fundamental practical or physical limits to this technology that will require a fundamental paradigm change in the role NIST plays in supporting industry? If NIST was to make significant improvements in measurement uncertainties or in measurement techniques for key microwave parameters, would these improvements facilitate advances in industry or would such efforts be wasted due to lack of impact? Is there a fundamental difference between the way the traditional defense and aerospace industries and other microwave industries (such as communications, wireless, medical, manufacturing and nonmilitary radar) meet their traceability requirements? If so, is there something that can be learned from the two processes? If NIST was just created today and given the charter of providing for national measurement support, what role would the microwave industry like it to play? Are there parameters that NIST does not support for which it should be providing measurement support? These questions are catalysts for the major question: Can a new and better paradigm be developed? We look forward to your participation.