This is a more advanced example using EQR_OPT_CST_DS. We are designing a combline diplexer starting from doubly terminated channel filters. Using the phasing method we can combine the two filters at a common junction. Once we capture the starting point with the optimizer we can easily modify the bandwidth, center frequency and spacing between channels. We can also add cross-couplings to either channel using the optimizer. Note that we start with doubly terminated filter designs. There is no need to synthesize singly terminated designs. In fact we are finding the singly terminated solutions via optimization rather than synthesis.