# T1 - A synthesis method for dual-passband microwave filters

Fig. 9(a) is an example of a coupling and routing diagram for a 5th degree canonical filtering circuit. It shows clearly why this configuration is referred to as the ‘wheel.’ with the main-line couplings forming the (partially incomplete) rim and the cross-couplings and input/output coupling forming the spokes. Fig. 9(b) shows the corresponding coupling matrix where the cross-coupling elements are all in the last row and column, and together with the main line and self couplings on the main diagonals give the matrix the appearance of an arrow pointing downwards towards the lower right corner of the matrix. The arrow matrix may be synthesized from the canonical transversal matrix with a formal sequence of rotations, similar to that of the folded matrix.

## filter network synthesis; coupling matrix; microwave filters

### Versatile Microwave - RF/Microwave filter synthesis …

Fig. 4. (A) Locked condition. (B) Out-of-lock conditions for a synthesizer using the exclusive OR phase detector. The output of the low-pass filter is a 2.5 volts DC signal (see text).

### Currently looking for beta testers of a new filter synthesis tool, ..

The continuous demands onthe filter performance, low manufactory cost and short developmentcycle from variant filter markets contribute to the driving forces tothe undergoing development and furtherance of microwave filter theory.

## Microwave Filter Synthesis, Non-resonating Nodes, …

A classical synthesis of microwave filters is based on a coupling matrix approach in which the matrix coefficients determine the filter topology. The first part of this webinar will focus on the conversion of the matrix into a 3D model. A typical workflow will describe the relevant modeling features available in CST MICROWAVE STUDIO® (CST® MWS® ). Two filter synthesis options will be described in detail. The new link between CST MWS and NuHertz allows the user to automatically generate CST® models of filters generated by NuHertz. In addition, we will present a specialized built-in macro for automatic band-pass filter synthesis and construction. The second part of the webinar will discuss suitable numerical approaches to the simulation itself, as well as the various tuning techniques – direct 3D simulation, space mapping techniques, group delay, and inverse Chirp-Z transformation – that can be applied in the design environment of CST STUDIO SUITE® . Finally, the modeling possibilities for thermal and mechanical analysis of high power filters, and multipacting issues for space-borne components, will be briefly discussed. Real world design examples will be used throughout.