Port Reduction of Multiport Cauer Ladder Network

The multiport Cauer ladder network (CLN) method is an efficient and accurate model order reduction (MOR) method for multi-input/multi-output (MIMO) systems. This manuscript discusses a theoretical aspect of port reduction in multiport CLN to generate a further reduced system. An intuitively derived method is found to be inaccurate. A recurrence formula and its practical implementation are presented to generate an accurate reduced system, which is proven by computational examples.