is parallel connections of L-R-C-G series resonant circuits [12]. \1.4.2   Brune’s equivalent circuit
The Brune’s equivalent circuit synthesis [13] is based on the propriety of P.R.
function. Let’s set the P.R rational function as W(s) =
either Z(s) or Y(s). The main idea of the Brune’s synthesis is that we separate a small part
of the function and obtain a new reduced P.R  function W’. By doing this in iteration, the
function reduces to one constant number which represents a resistor or a conductor.
Investigation of Lumped Element Equivalent Circuit for Distributed Microwave Circuit(4):http://www.751com.cn/yingyu/lunwen_1765.html