S-Parameter Analysis of Age Testing Effects on FR4-Based Printed Circuit Boards up to 10 GHz

To allow fast deployment of new communication technologies all over the world, devices compliant with these standards must be able to operate over a wide range of temperatures and humidity conditions. Considering that these devices are usually implemented on Printed Circuit Boards (PCBs), knowing how the PCB substrate is influenced by extreme humidity and temperature or by their fluctuations is fundamental. This paper aims to investigate the impact of these environmental effects on a Flame Retardant 4 (FR4)-based evaluation PCB suitably designed for this scope. Preliminary results of tests carried out by both the National Physical Laboratory (NPL) and the Institute of Metrology of Bosnia and Herzegovina (IMBiH) will allow the designer to optimize their choice of the substrate by balancing cost with performance with life expectancy in its intended environment of operation.