Decoupling high frequency signals from a DC supply

Not only for developers—the latest release ANP101: RF Gain Block Amplifier with Integrated Multilayer Ferrite Bead for Broadband Operation addresses how the transmission characteristics of an RF amplifier can be enhanced and improved by the right choice of components and an optimal layout.

From 5G systems to radio and antenna applications, wireless communication accompanies us throughout our daily lives. So the demand for universal high-frequency amplifiers is correspondingly high. By selecting the optimal passive components, the transmission characteristics of the amplifier can be improved during development. A well-designed layout further improves RF performance. The aim is to transmit both RF signals and the DC supply on a single line without interference or cross-talk. A key component is the inductor for decoupling the RF and DC supplies.

Measurement setup for evaluating circuit alternatives Besides standard inductors, multilayer ferrites are also used. To compare and evaluate the two alternatives, Würth Elektronik specialists designed and tested a RF amplifier evaluation board. The setup and measurement results are documented in the application note. ANP101 also includes circuit design recommendations for setting the optimum parameters using two RF amplifier examples. It also describes how to select components specifically with the online simulation tool REDEXPERT from Würth Elektronik or how to dimension the DC block capacitor correctly.