A note on the design of broad-band impedance matching networks

Formulas are given which are intended to assist in the design of simple low-pass networks to match a resistive source to a complex load impedance when the desired type of frequency response does not coincide with one for which explicit formulas for the element values have been published to date. Third-order elliptic is one such response, and its adoption in a matching network allows some compromise to be achieved between matching and filtering performance. The formulas are applicable to the design of matching networks whose response, when connected to the load, is of second or third-order polynomial form or, alternatively, third-order elliptic (or similar). All the networks are suitable for parallel (or series) load impedances and, in the case of the polynomial networks, for certain (or ) loads also.