There are a number of circuits that require coupling RF signals or bypassing them to ground while blocking DC over extraordinarily large RF bandwidths. The applications for which they are intended typically require small, surface-mountable (SMT) units with low insertion losses, reflections, and impedances across RF frequencies extending from the tens of KHz to the tens of GHz. and temperatures typically ranging from -55 to +85C. This note focuses on a particular implementation of these devices -- multilayer ceramic capacitors (MLCCs)- and how to obtain the best performance when they're used on various substrates.

Broadband capacitors are used in the "signal integrity" market -- optoelectronics/high-speed data; ROSA/TOSA (Transmit/Receive optical subassemblies); SONET (Synchronous Optical Networks); broadband test equipment - as well as in broadband microwave and millimeter wave amplifiers (MMICs, GaN transistors) and oscillators. The basic requirement in the former is to produce an output waveform that closely replicates an input waveform, typically a train of digital pulses.Product Features