Co-simulation tuning methods for lumped element filters

With the advent of higher speed communication links comes the requirement for ever wider link bandwidths. Channel filtering provides a critical part of any up-converter or down-converter. A typical down-converter encapsulates an Image Filter, a mixer, several Amplifiers, and baseband channel filtering, typically at frequencies less than 500MHz. Traditional high-loss transversal SAW filters are typically used, but can now be replaced with an alternative approach using lumped element technology. These offer many advantages to SAW filters, including low loss, excellent thermal stability, improved stopband rejection, and wideband filtering at low centre frequencies (>;30%). This paper discusses the constraints on complex lumped element filter design and realisation, and demonstrates how these difficulties can be overcome with a novel co-simulation technique with a practical example using PCB technology.