Dr. Joel Dunsmore

On Thursday, May 21, 2026, the IEEE MTT-S Japan/Kansai/Nagoya Chapters DML (Distinguished Microwave Lectures) lecture was successfully held at the Ookayama Campus of the Institute of Science Tokyo.

We welcomed Dr. Joel Dunsmore of Keysight Technologies as the speaker. Dr. Dunsmore is one of the world-leading researchers specializing in the research and development of vector network analyzers (VNAs) and VNA-based measurements. In recent years, he has been particularly active in the fields of nonlinear measurements, including differential device and mixer measurements, as well as modulation and spectrum measurements.

Speaker: Dr. Joel Dunsmore (Keysight Technologies)

Title: Modern Methods for Component Measurements using Vector Network Analyzers

Abstract: Modern Vector Network Analyzers (VNA) have flexible hardware and software with much higher performance than VNAs of even a few years ago. There are a wide range of measurement applications, beyond simple S-parameters, that a VNA can address, and with precision that cannot be achieved by other test methods. VNAs now act as a multi-functional test system, providing an extremely wide range of device- and signal-characterization capabilities including noise figure, gain-compression, true-mode differential device characterization, two-tone Inter-Modulation Distortion (IMD), phase-noise, mixer and frequency converter gain/phase/delay measurements. Very recently Vector Spectrum Analysis (VSA) capabilities have been added, including measurements of complex modulated signals such as Error Vector Magnitude (EVM), Adjacent Channel Power Ratio (ACPR) and characteristics of Digital Pre-Distortion (DPD). These capabilities, when properly configured, provide the most precise measurements of high-frequency mm-wave and sub-THz modulated signals, beyond the capabilities of stand-alone measurement instruments, as was demonstrated using 20 GHz bandwidth modulated signals at 250 GHz. This lecture illuminated the methods and capabilities for these advanced measurement methods for characterizing microwave components.

Following the lecture, a reception was held with Dr. Dunsmore, providing an opportunity for friendly conversation and a lively exchange of technical insights.