Model-Driven Design of Microwave Filters Based on Scalable Circuit Models

Abstract

Most microwave filters are currently designed using direct electromagnetic (EM) optimization. This method holds several disadvantages regarding the provided physical insight to designers and duration of the optimization process. To circumvent these drawbacks, we propose a filter design based on scalable circuit models. This model-driven design competes with EM optimization by maintaining the accuracy of the optimization results while providing a very significant speedup and gaining physical insight on the EM working mechanism of the filter of interest. This paper discusses the advantages of using the proposed model-driven design by the illustration on a defected ground structure filter. A scalable equivalent circuit model is used in the design procedure to provide physical insight to the designer and to speed up the design process enormously.

On Computationally-Efficient Reference Design Acquisition for Reduced-Cost Constrained Modeling and Re-Design of Compact Microwave Passives

“…1(a) at a certain initial design (---), the design optimized for the operating frequency of 2.0 GHz (-), as well as responses evaluated along the line segment connecting these two designs, and parameterized using 0  t  1 (grey lines); (b) conventional objective function (6) (---) and feature-based objective function (8) (-) as a function of t. It can be observed that the feature-based cost function is monotonic so that the optimum design is attainable through local search. This is not the case for the formulation(6).…”

“…Notwithstanding, the landscape of UF() is more regular than that of U(). Consequently, optimizing the coupler using (8) is, in generally, computationally cheaper than when using (6). As a matter of fact, the second penalty term in (8) can enforce monotonicity of the objective function profile so that the optimum solution is attainable even when starting from a relatively remote initial design (cf.…”

“…Despite the advancements in the development of computing software and hardware, the high cost of repetitive simulations incurred by parametric optimization [3] or uncertainty quantification [4], is still a major bottleneck of EM-based design procedures. These issues are particularly pertinent to miniaturized microwave components where traditional design methods involving network-equivalent models are only capable of yielding initial designs that require further tuning [5], [6]. Furthermore, the layouts of compact structures are typically described using larger numbers of parameters than the conventional circuits, because their construction involves slow-wave-based [7] building blocks such as compact microstrip resonant cells (CMRCs) [8], defected ground structures (DSGs) [9], or transmission line (TL) folding [10].…”

An equivalent circuit model for wide‐band analysis of defected ground structures with asymmetric slot and multiple slots

“…The losses are introduced in References 4 and 5 by using a cascade of RLC‐tanks to model multiple antiresonances. In Reference 6, we proposed a parsimonious and accurate equivalent circuit model with losses to model the fundamental frequency for a DGS consisting of a single rectangular slot positioned perpendicularly to and symmetrically around the transmission line. Such a DGS is shown in Figure 1 (Middle).…”

“…Such a DGS is shown in Figure 1 (Middle). In Reference 7, we extended the equivalent circuit model from Reference 6 to a wide‐band model that is able to take into account multiple antiresonances.…”