Fixturing impacts on high-frequency low-resistance, low-inductance impedance measurements

Multiple off-the-shelf test-fixtures are available to interface a device-under-test (DUT) to an impedance analyser to characterise its electrical properties. The impact of three available fixtures on the measured impedance of a low-resistance, low-inductance DUT requiring high-frequency (≥100 MHz) characterisation are compared with a custom fixture. The custom fixture is shown to provide a higher accuracy than the off-the-shelf fixtures, highlighting that low-resistance, low-inductance devices require carefully constructed fixtures for characterisation. The experimental results collected using the fixtures are validated against a finite-element-analysis model of the DUT.