As more digital circuits are being implemented into car radios, the adverse impact of digital noise to a RF circuit becomes more evident. There are ways to minimize the impact by using proper shields, right conductors/components layouts, and software strategy, etc. In this paper, we will discuss how to identify noise sources, and how to use the keypad and display control software and other techniques such as a suitable power/ground system, and double-shielding of the digital and the RF circuits to tackle the noise problem in a DSP (Digital Signal Processing) radio.
