RF Circuit Performance Optimization in Microcontroller Based Circuits in Road Vehicles

Any circuit system employing RF signals emit EM waves which might interfere with adjoining active circuits. A printed circuit board contains metallic strips known as PCB traces carrying signals for circuit functioning. PCB traces can turn into antennae (transmitting or receiving) depending upon the PCB design and the type of signal which they carry. RF systems used in automotive domain ranges from 300MHz to several GHz depending upon the application requirements. Due to space constrains, most the time it is required to design a mixed signal (analog and RF) circuits on single PCB, this constraint leads to crosstalk and other interferences. This paper explains the common pitfalls encountered in designing analog circuit along with RF circuit on the same PCB also this paper gives insight of RF circuits used in automotive remote keyless entry systems coupled with body control module ECU. Finally this paper sums up with methods implemented to minimize the interference between Analog and RF circuits.