A toolbox to compute matching filters

PUMA toolbox solves the problem of broadband matching. This problem consist on the computation of a rational 2-port filtering function presenting a reference impedance (i.e. 50 Ohm) at the first port, and the conjugate of the load impedance within a frequency band at the second port.

Broadband Matching Problem

The objective of the matching problem is to find the matching filter F of degree N, that minimises, in a given frequency band, the reflection of the system S, composed of the filter cascaded with the load L

Selectivity constraints can be added to the matching filters to suppress a given frequency band as it is customary in classical filter synthesis.

Additionally, prescribed transmission zeros can be added, for instance, next to the passband to increase selectivity or as conjugate pairs in the complex plane to control the group delay.

With the previous specifications, this toolbox computes:

• The lower limit for the matching level that can be obtained with a filter of degree N
• The required filtering function of the same degree to approach the limit.