Software-defined radio (SDR) requires complex circuitry on printed circuit boards (PCBs) that defines the functionality of the device as well as the performance of these microwave and RF systems. This article discusses the factors that arise when designing PCBs for SDRs that need to maintain signal integrity.
An SDR includes what’s commonly termed a radio front-end (RFE) and digital backend. The RFE boards contain the functionality of the radio over a very wide tuning range and incorporate various analog components such as LNAs, mixers, filters, frequency synthesizers, gain/attenuation blocks, and other devices needed for receiving (Rx) and transmitting (Tx) functionality.