Application Description

High-performance components are critical when developing faster and smaller electronic devices. A prime example is the capacitor, which is often called upon to ensure an extremely low equivalent series resistance (ESR). Capacitors with this property have a high quality factor Q or, equivalently, low loss or low dissipation D. As Q represents the efficiency of the capacitor, that is, the ratio of energy stored to energy dissipated per cycle, it is related to the ESR (R_ESR) as Q = 1/(ω C R_ESR), where ω is the angular frequency and C is the capacitance.

High-Q capacitors are required for RF power stages, demanding filter applications, and as bypass elements. Manufacturing high-Q capacitors requires high-temperature sintering with careful control of the dielectric layer thickness, the dielectric constant of the ceramic material, and the volumetric form factor defining the effective area. This process leads to a manufacturing variability such that even capacitors with the same part number can exhibit very different Q values. For this reason, optimal circuit design necessitates the ability to measure Q, D and the ESR over the full working frequency range of the component.