The rapid growth of telecommunication applications requires support from reliable millimeter-wave power measurement standards and systems. A highly accurate and precise measurement system is essential not only for validating the performance of telecommunication devices but also for ensuring safety, meeting regulatory requirements, and improving system efficiency. Currently, microcalorimeters, which serve as the primary measurement standard for radio frequency (RF) power at National Metrology Institutes (NMIs), are limited at frequencies up to 170 GHz. However, there is a growing demand for measurement standards at higher frequencies, such as those required for the sixth-generation (6G) technology for wireless communications. This dissertation focuses on developing a millimeter-wave power measurement standard and system for the frequency range of 140 GHz to 220 GHz to support telecommunications infrastructure.

Millimeter-wave technology applications, whose frequency range is not covered by existing standards, have encouraged research to find solutions. The development of microcalorimeters for the millimeter-wave range is challenging, primarily due to significant losses in the transmission lines. Since a microcalorimeter is a heat-measuring instrument, fluctuations in ambient temperature further complicate its implementation. In this work, a microcalorimeter was designed with a twin-line structure, featuring a symmetrically arranged transfer standard and a dummy load. The dummy load serves as the temperature reference, while the transfer standard is connected to a feeding line, and the dummy load to a dummy line. Both lines were constructed from dielectric waveguides, rather than metal waveguides as used in many conventional microcalorimeters. The feeding line utilizes metal waveguides as a transition section to connect the dielectric waveguide with rectangular waveguide (WR) devices, particularly WR-5 standardized devices.

A dielectric waveguide microcalorimeter was fabricated as the primary measurement standard for millimeter-wave power, demonstrating good performance. Effective transmission line matching has been achieved by tapering the ends of the dielectric rod waveguide and shaping the hollow metal waveguide into a trumpet structure. Enclosing the microcalorimeter in thermal jackets maintains a stable temperature. The twin-line structure minimizes the effects of temperature variations. The dielectric waveguide microcalorimeter is utilized to calibrate power sensors, establishing measurement traceability for millimeter-wave devices. This microcalorimeter represents a novel application of dielectric waveguides in the WR-5 band, contributing to quality assurance in the development of telecommunications systems.