Probe Measurement System for Surface Mount Devices at Radio Frequencies

This paper presents a new probe system for measuring the scattering parameters of surface mount devices in radio frequency range in response to the demand for operating power devices at higher frequencies. Two ground-source probes with 3.7 mm pitch and a probe station for controlling these probes were designed as original components of the proposed system. When used with a commercially available vector network analyzer, a de source supply, two bias-Ts, and cables, the scattering parameters with the de bias voltage supplied can be measured. This is a pioneer probe measurement system for surface mount devices in the power electronics operated at the radio frequencies. Because the probes can be used in direct contact with a surface mount device under test, precise measurement results can be obtained. The evaluation results for the stability of the developed system and contact reproducibility are also presented. Around the low reflection area, the stability of the system and the contact reproducibility of the magnitude of S11 were less than 0.00007 from 50 kHz to 300 MHz. However, these values increased at the frequencies over 1 GHz. It is confirmed that probe control is important in probe measurements especially at high frequency range.