What is the purpose of a ground plane in PCB design?

The purpose of a ground plane in PCB design is to provide a common ground. A ground plane serves as a reference point for all voltages in the circuit, ensuring that all components have a uniform electrical reference. This is crucial for maintaining signal integrity, as it reduces the potential for noise and interference in the circuit. By offering a low-resistance return path for electrical currents, ground planes help to stabilize voltages and minimize the effects of crosstalk between traces.

Moreover, a well-designed ground plane can facilitate efficient thermal management and improve electromagnetic compatibility, leading to better overall performance of the electronic device. The ground plane plays a significant role in defining the electrical characteristics of the circuit, making it a fundamental aspect of PCB design for reliable functionality.