The Performance of Passive Lumped Element

Abstract

Lumped elements are the most widely used passive components in Radio Frequency (RF) circuits. The characteristics variation over change in frequency, however, limits their application. This limitation stems from the physical dimensions of lumped elements, which are, in general, 0603, 0402, and 0201 size in order to avoid the phase shift between the input and the output. By examining the Quality Factor (Q) and Self-Resonant Frequency (SRF), the performance of lumped elements can be determined. The quality factor contains the energy storing and dissipation terms, which vary according to frequency. This quality factor can be obtained using the S-parameters of lumped elements. It is difficult to obtain accurate measurement of a non-coaxial package device such as a lumped inductor, because it cannot be measured using a calibrated measurement system. A Print Circuit Board (PCB) fixture is thus considered to connect a Device Under Test (DUT) to 50 ohm connectors, and the effects of the fixture are then removed by performing a user fixture standards calibration. The combination of a port extension and calibration using a manufacturer’s calibration kit is employed to collect one-port S-parameters. The best result is achieved using a SubMiniature version A (SMA) fixture that has a short line and good impedance matching This thesis presents an extraction method to derive the quality factor of lumped elements, and the quality factor is obtained using one-port S-parameters.