Second-order Transfer Functions

This chapter teaches how to apply the Extra Element Theorem (EET) technique to second-order systems known as the Two Extra Element Theorem (2EET). It first explore the raw expression of the 2EET. The Extra Element Theorem considers that any 1^st-order network transfer function can be broken into two terms: the leading term, or the reference gain, is obtained with the extra element Z put in its reference state. The idea behind the Two Extra Element Theorem (2EET) theory is to apply the EET twice to a network containing two energy-storing elements, Z1 and Z2. The EET is applied to a first energy-storing element while the second is set in its reference state. The EET is further run a second time over the second element with the first one back in place, leading to complex driving impedances. Assembling these factors leads to the transfer function of a 2nd-order network.