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

T1 - General coupling matrix synthesis method for microwave resonator filters of arbitrary topology

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.

A method is presented for the efficient optimization of microwave filters and multiplexers designed from an ideal prototype.

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.


Advanced Synthesis Techniques for Microwave Filters ..

Because of its simplicity, the box filter is useful for the design of transmit/receive diplexers, which are very often found in the base stations of cellular telephony systems. An example of a simple diplexer comprising two complementary-asymmetric 4th degree filters, each with one transmission zero producing a 30 dB rejection lobe over each other’s usable bandwidth. Is shown in Fig. 17(a), and its performance is shown in Fig. 17(b). This diplexer was designed using software that optimizes the length and impedances of the common-port coupling wires as well as the first few elements of each filter nearest to the CP (coupling values, resonator tuning frequencies). In practice, much greater Tx-Rx isolation is usually required, and higher degree filters with more transmission zeros have to be used.

Abstract—In this paper a synthesis procedure for duplexers that can work simultaneously at two different frequency bands is presented.

A Direct Synthesis Approach for Microwave Filters …

A microwave filter topology that has found widespread application in both terrestrial and space systems is the ‘trisection.’ The basic trisection may be used as a stand-alone section or be embedded within a higher-degree filter network. But often multiple trisections are merged to form advanced configurations such as cascaded ‘N-tuplets’ or box filters.

Such synthesis techniques arealso embedded into electromagnetic (EM) simulation and physicalconfiguration in the design stage of microwave filters.

Filter Synthesis Software - Nuhertz

The CST® Filter Designer 3D is a complete synthesis tool for narrow bandpass filters and diplexers. It offers a range of solutions throughout the design process of a coupled-resonator filter – regardless of whether it is implemented in planar, waveguide or dielectric media. The synthesis is based on the coupling matrix and also provides a unique feature that assists in the tuning phase of a 3D filter.