This is a free version of Couplings Designer limited to 4th order filters. Unlimited orders are available in the full version.Couplings Designer allows efficient design of advanced RF and microwave filters using any given technology. A powerful hybrid synthesis technique taking advantage of both exact polynomial approximation with prescribed zeros and optimization reduces the time and effort required to find an optimum coupling matrix. The full range of zeros available for a given filter order and topology are easily engineered to fit your specification. The synthesized coupling matrix can be realized as lumped components, distributed elements, waveguide structures or any exotic resonator and coupling mechanism imaginable.Key features include: bandpass or bandstop response synthesis with prescribed zeros predistortion non-resonating nodes, NRNs cascading of designs (modular filter design), not supported in Couplings Designer Lite an advanced optimizer an arbitrary topology transformer Monte Carlo tolerance analysis tuning of individual or symmetrical couplings couplings are represented as physical or normalized markers and handy multi-touch gestures for scaling plot axes export matrix and S-parameter dataA suitable coupling matrix and topology is found within minutes. A typical design flow with Couplings Designer consists of: setting up goals, or in other words filter specifications, based on rejection, ripple and group delay requirements specifying a filter order, bandwidth, center frequency and resonator quality synthesize a seed coupling matrix that may include prescribed zeros and/or predistortion transform to a topology suitable for implementation, arbitrarily specified or using built-in presets (folded, arrow, cul-de-sac, extended box) manual tuning and/or optimization tolerance check using Monte Carlo analysis export the design to a computer realize the coupling matrix using computer software or empirical methodsCouplings Designer is a tool suitable for professional filter engineers, system engineers and students alike.