CoupleFil is a synthesis tool for designing cross-coupled bandpass filters, and will complement and extend CST's workflows for simulating and optimizing filters. Cross-coupled filters are commonly used for high-frequency, high-performance applications where narrow passbands and steep roll-off are required, for example in telecom base stations and satellites. Cross-couplings (couplings between non-adjacent resonators) can be used to modify the filter transfer function. They are mostly employed for improving the filter selectivity by producing transmission zeroes. Depending on their sign, they can also be employed for improving filter phase linearity.

More Information: cst.com/couplefil