Jens Bornemann

Adaptive synthesis and design of resonator filters with source/load-multiresonator coupling

The paper presents a universal and comprehensive synthesis technique of coupled resonator filters with source/load-multiresonator coupling. The approach is based on repeated analyses of a circuit with the desired topology; no similarity transformation is needed. Restrictions imposed by the implementation on the coupling coefficients such as signs and orders of magnitudes are straightforwardly handled within this technique. The technique is then used to synthesize and design filters with full or almost full coupling matrices by selecting, among the infinite number of solutions, the matrix that corresponds to the actual implementation. In such cases, analytical techniques and those based on similarity transformations cannot be used since they provide no mechanism to constrain individual coupling coefficients in order to discriminate between two full coupling matrices, which are both solutions to the synthesis problem. Using the technique described in this paper, a filter designer can extract the coupling matrix of a filter of arbitrary order and topology while enforcing relevant constraints. There is no need to master all the different existing similarity-transformation-based techniques and the topologies to which they are applicable. For the first time, detailed investigations of parasitic coupling effects, for either compensation or utilization, are made possible. The method is applied to the synthesis of a variety of filters, some of which are then designed and built and their response measured.

Coupling-Matrix Design of Dual and Triple Passband Filters

The concept of the conventional coupling matrix is extended to include designs of dual- and triple-band filters. The multiband response is created by either placing transmission zeros within the bandwidth of a wideband filter or using higher order resonances. Realizable topologies both in planar and waveguide technologies can be imposed and associated coupling coefficients enforced during optimization. The design process is verified by measurements and comparison with results of commercially available field solvers

Optimized Waveguide E-plane Metal Insert Filters For Millimeter-wave Applications

A design theory is described for rectangular waveguide metal insert filters that includes both higher order mode interaction and finite thickness of the inserts. Optimized design data for three- to five-resonator type filters with severaf insert thicknesses suitable for metal stamping and etching techniques are given for midband frequencies of about 15, 33, 63, and 75 GHz. Measured passband insertion losses of prototypes for mid-band frequencies of 15, 33, and 76 GHz are 0.2, 0.6, and 0.7 dB, respectively.

A Novel Frequency-Selective Power Combiner/Divider in Single-Layer Substrate Integrated Waveguide Technology

A frequency-selective power combiner/divider in single-layer substrate integrated waveguide (SIW) technology is introduced. The basic building block consists of a planar four cavity structure with three of them operated in SIW TE101 modes and one in SIW TE201 mode. Each cavity is coupled to one port of the unit. In addition the overall configuration considers couplings of each resonator to the two adjacent ones. Due to the coupling transformation properties of the TE201 mode cavity, second order 3 dB transfer functions are obtained from each port to two adjacent ones while the fourth port is almost isolated. The novel combiner/divider is designed for 11 GHz and prototyped on RT/Duroid 5870 substrate. Measurements verify the design process and operation of the device.

Singlets, cascaded singlets, and the nonresonating node model for advanced modular design of elliptic filters

The singlet, which contains one resonator and generates one transmission zero, is introduced as the most basic building block for modular design of elliptic filters. Higher-order elliptic filters are designed by cascading singlets to generate the required transmission zeros. A novel model, the nonresonating node model (NRNM), which contains both resonating and nonresonating nodes is then introduced. The model allows a high level of modularity in the design of elliptic filters. Example filters are designed and measured to validate the model and the design approach.

Compact single-channel rotary joint using ridged waveguide sections for phase adjustment

A new design for single-channel waveguide rotary joints for high-power applications is presented. In order to obtain correct signal phase conditions along the ring and, at the same time, reduce the diameter of the rotary joint, tapered ridged waveguide sections are introduced. Design guidelines with respect to general transmission characteristics, H-plane aperture couplers, and ridge waveguide analysis are presented. Measurements of a 9.05-GHz prototype show less than 1-dB insertion loss over a 250-MHz bandwidth and, hence, verify the design concept.

Ridge waveguide polarizer with finite and stepped-thickness septum

This contribution presents new design dimensions for the ridge waveguide septum polarizer. Emphasis is placed first, on including the finite septum thickness in the analysis; second, demonstrating its influence on the polarizer performance; third, including a stepped approach for extremely thick septa; fourth, optimizing components without the need for additional phase-adjusting structures; and fifth, providing the application engineer with some design guidelines. Examples for varying septum thickness and/or number of sections are given for C-, X-, R120-, Ku- and K-band applications. The analysis is based on an efficient mode-matching technique. Evolution-strategy methods are used for optimization. Both algorithms are translated into PC-operational software. Results are compared with previously published theoretical/experimental polarizer data and with a finite-element analysis, and are found to be in good agreement. >

Theory and Design of Low-Insertion Loss Fin-Line Filters

A design theory is described for low-insertion loss fin-line filters that includes both higher order mode propagation and finite thickness of the dielectric substrate and the metallic fins. Design data for three-resonator type fin-line filters with several substrate thicknesses are given for midband frequencies of about 15, 34, and 66 GHz. The measured insertion losses in the passband are 0.25, 0.5, and 1.3 dB, respectively, for these three frequencies.

Short-Term Operation Scheduling in Renewable-Powered Microgrids: A Duality-Based Approach

This paper considers the operation scheduling problem in renewable-powered microgrids, which is used to determine the least-cost unit commitment (UC) and the associated dispatch, while meeting load, environmental, and system operating requirements. The intermittency nature of the renewable energy sources, as well as microgrids capacity to operate either in parallel with, or autonomously of, the traditional power grid, pose new challenges to this classic optimization task. A probability-based concept, probability of self-sufficiency (PSS), is introduced to indicate the probability that the microgrid is capable of meeting local demand in a self-sufficient manner. Furthermore, to the best of our knowledge, we make the first attempt in approaching the mixed-integer UC problem from a convex optimization perspective, which leads to an analytical closed-form characterization of the optimal commitment and dispatch solutions. The simulation results show that 1) the proposed method achieves an efficient performance that incurs no loss of optimality with lower complexity than existing algorithms; 2) an energy storage system (ESS) with suitable capacity contributes to the self-sufficiency target of a microgrid, and the stored energy varies less remarkably as the microgrid tends to operate more independently; 3) the proposed method provides guidelines in deciding the ESS size to achieve a desired PSS.

Matrix singular value decomposition for pole-free solutions of homogeneous matrix equations as applied to numerical modeling methods

A general technique for solving homogeneous matrix equations as applied to numerical modeling procedures in microwave and millimeter-wave structures is introduced. By using singular value decomposition, well-known numerical problems related to poles and steep gradients in the determinant function are eliminated. The proposed technique is generally applicable, improves the accuracy and reliability of computed results, and significantly reduces the CPU time due to a more moderate behavior of the function to be analyzed. A dispersion characteristics example of a conductor-backed slotline MMIC structure illustrates the advantage of the pole-free formulation over conventional determinant calculations.<<ETX>>