Application Note on Broadband Capacitors

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 +85 0C. 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.