F. Arndt

Universität Bremen, Bremen, Bremen, Germany

Are you F. Arndt?

Claim your profile

Publications (174)122.88 Total impact

  • F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: In this article we will briefly report on recent advances of this hybrid CAD approach, which is characterized, in particular, by a further breakthrough in EM design and optimization speed. The significant importance for the IEEE MTT Society community is that, in this way, direct, full-wave EMdesign and optimization of advanced microwave structures and antennas can be performed within shorter design cycles. Representative application examples of industrial microwave devices/antennas will demonstrate that EM simulation times can be reduced on standard PCs (without additional hardware acceleration tools) now typically to a few seconds. Appropriate synthesis wizards provide good starting values for subsequent EM optimizations. Available measurement data verify the high accuracy of the presented hybrid EM technique.
    IEEE Microwave Magazine 01/2009; · 1.50 Impact Factor
  • V. Catina, F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: For protecting antennas from environmental effects, and preserving aerodynamic profiles of objects with antennas, dielectric radomes are used already for a long time [1]. The presence of radomes, which commonly have different shapes, cf. e.g. [2], can significantly affect the radiation characteristics of corresponding antennas, and, hence, their analysis has found much attention in the recent past. For aperture antennas with radomes, cf. schematic sketch in Fig. 1 [3], many different techniques have been applied so far, such as ray optics [4], equivalence principles with image theory [5], integral equation (IE) methods for 2D problems [6], hybrid physical optics-method of moments (PO-MoM) techniques [3], and the finite-difference time-domain (FD-TD) method [7]. Approximate methods can lead to accuracy problems, 3D solvers can be too time consuming for desirable optimizations.
    Antennas and Propagation Society International Symposium, 2008. AP-S 2008. IEEE; 08/2008
  • F. Arndt, V. Catina, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: The paper presents an overview on recent progress in the application of hybrid mode-matching (MM) / finite-element (FE) / method-of-moment (MoM) techniques for the rigorous, fast computer-aided-design (CAD) and optimization of waveguide feed components and antennas. Advanced aspects include the application of the PMCHWT (Poggio, Miller, Chang, Harrington, Wu, Tsai) method for dielectric loaded structures, the utilization of higher-order vector basis functions, and the adaptive integral method (AIM) for large arrays. The employed divergence-conforming basis functions, which have hitherto mostly been applied for scattering and microstrip antenna problems, achieve - together with curvilinear triangles for adequately modelling of curved surfaces - high efficiency, accuracy and flexibility. The versatility of the reported techniques are demonstrated at typical examples of practical importance, including dielectric loaded structures and large slot arrays.
    Antennas and Propagation, 2007. EuCAP 2007. The Second European Conference on; 12/2007
  • V. Catina, F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: Dielectric loaded horns have found widespread application due to their inherent potential of having features similar to corrugated horns, while being less frequency sensitive and more easily to be manufactured, in particular for higher frequencies. In this paper, we follow a different MoM approach by using divergence-conforming higher-order vector basis functions, which have mostly been employed for scattering and microstrip antenna problems so far. Moreover, curved surfaces is modeled using curvilinear triangles in order to minimize geometrical modeling inaccuracies. The advantages include higher efficiency, accuracy and flexibility. For solving the given problem, the electric field integral equation (EFIE) is combined with the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) formulation. The combined formulation is named EFIE-PMCHWT method underlining the fact that the EFIE is applied to model the fields on the aperture and conductor surfaces, and the PMCHWT method is utilized for modelling dielectric structures inside the waveguide housing.
    Antennas and Propagation Society International Symposium, 2007 IEEE; 07/2007
  • V. Catina, F. Arndt, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A combined electric field integral (EFIE) Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) surface integral equation technique is presented, in which divergence-conforming higher order vector basis functions are applied. Curved surfaces are modeled using curvilinear triangles in order to minimize geometrical modeling inaccuracies. Conforming vector bases provide appropriate continuity at material interfaces and allow for imposing boundary conditions on unknown fields or currents. The advantage of the proposed method against existing approaches is its higher efficiency and flexibility. The versatility and accuracy of the method are verified at typical filter examples by comparison with reference results.
    Microwave Symposium, 2007. IEEE/MTT-S International; 07/2007
  • F. Arndt, V. Catina, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: The paper describes the application of efficient hybrid mode-matching (MM)/finite-element (FE)/method-of-moment (MoM) techniques for the rigorous, fast computer-aided-design (CAD) and optimization of waveguide components and antennas. Advanced aspects involve a surface integral equation MoM technique for the design of arbitrarily shaped three-dimensional waveguide elements including dielectric structures, and the application of the adaptive integral method (AIM) for the efficient calculation of large arrays. The described hybrid techniques combine advantageously the efficiency of the MM method with the flexibility of FE and MoM methods. Typical application examples demonstrate the versatility of the presented hybrid techniques; their accuracy and efficiency is verified by available measured results.
    Microwave Conference, 2006. APMC 2006. Asia-Pacific; 01/2007
  • I. Rullhusen, F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: A method-of-moment (MoM) technique is presented for the rigorous analysis of multi-layer reflectarrays using microstrip patch elements of variable size. The electric field integral equation (EFIE) in mixed potential form is discretized using Rao-Wilton-Glisson or rectangular basis functions, respectively. The required Green's functions are evaluated by Felsen's equivalent transmission line method. For the efficient MoM computation, the adaptive integral method (AIM) is applied.
    Antennas and Propagation, 2006. EuCAP 2006. First European Conference on; 12/2006
  • V. Catina, F. Arndt, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A combined electric field integral (EFIE) Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) surface integral equation technique is presented, in which exclusively Rao-Wilton-Glisson (RWG) functions are used for basis functions. This yields the accurate analysis of coax-fed dielectric resonator filters. The advantage of the proposed method against existing approaches is its higher efficiency and flexibility. The versatility and accuracy of the method are verified by comparison with measured results
    Microwave Conference, 2006. 36th European; 10/2006
  • V. Catina, F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a surface integral method for the rigorous analysis of edge-slot arrays of finite extension. The free space Green's function provides the desired flexibility. The numerical solution by the method-of-moments (MoM) allows the convenient calculation of the antenna pattern and of the generalized admittance matrix at the waveguide ports including higher-order modes for the intended further combination with fast hybrid mode-matching/finite-element (MM/FE) building blocks. The flexibility and accuracy of the method is verified by available reference results and measurements
    Antennas and Propagation Society International Symposium 2006, IEEE; 08/2006
  • F. Arndt, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A hybrid mode-matching/finite-element (MM/FE) method is described for the rigorous CAD and optimization of ridged waveguide filters and diplexers appropriate for low-temperature cofired ceramic (LTCC) fabrication techniques. The advantage of the proposed method against existing approaches is its high efficiency while maintaining the flexible solution for arbitrary cross-sections. A new ridged waveguide bi-furcation element achieves the convenient divider-type diplexer combination. The accuracy of the presented method is verified by available reference measurements. Its efficiency and flexibility is demonstrated by typical examples.
    Microwave Conference Proceedings, 2005. APMC 2005. Asia-Pacific Conference Proceedings; 01/2006
  • V. Catina, F. Arndt, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A surface integral-equation method is combined with the mode-matching technique for the rigorous efficient analysis of waveguide filters containing arbitrarily shaped dielectric posts in arbitrary waveguide housings. The advantage of the proposed method against existing approaches is its high flexibility for calculating structures being not restricted by specific canonical shapes. A locally refined adaptive triangular surface mesh, together with the application of Rao-Wilton-Glisson and aperture eigenfunctions, respectively, for basis functions, achieves reliable modeling. The accuracy of the presented method is verified by available measurements.
    IEEE Transactions on Microwave Theory and Techniques 12/2005; · 2.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A hybrid mode-matching (MM)/method-of-moment (MoM) technique is presented for the rigorous analysis of the six-port junction of a conical circular waveguide with four side-coupled rectangular waveguides. The effects of the cone and of aperture curvature are rigorously taken into account. The advantage of the conical structure in comparison with its cylindrical counterpart includes achieving additional design potential, which can be applied e.g. for ortho-mode transducers (OMTs) of improved performance. The accuracy and efficiency of the method are verified by comparison with reference values.
    Microwave Conference, 2005 European; 11/2005
  • Source
    V. Catina, F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: Dielectric loaded horns have found widespread application due to their many attractive features. We present a surface integral method for the rigorous analysis of horns containing arbitrarily shaped dielectric structures and a waveguide aperture. The method is based on the PMCHWT formulation (named after Poggio, Miller, Chang, Harrington, Wu, and Tsai) (Chu, Y. et al., IEEE Trans. Antennas Propag., vol.AP-51, p.2837-44, 2003), which has hitherto been restricted to scattering problems. The numerical solution by the method-of-moments (MoM) allows the efficient calculation of the antenna pattern and of the generalized admittance matrix at the waveguide port, including higher-order modes for the intended further combination with fast hybrid MM/FE (mode-matching finite element) building blocks (Arndt, F. et al., IEEE Trans. Microwave Theory and Tech., vol.MTT-52, p.292-305, 2004.). The efficiency and accuracy of the method is verified by available measurements.
    Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
  • V. Catina, F. Arndt, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A surface integral equation method is presented for the rigorous analysis of arbitrarily shaped dielectric posts in arbitrary waveguide housings. The advantage of the proposed method upon existing approaches is its high flexibility for calculating structures being not restricted by specific canonical shapes. A locally refined adaptive triangular surface mesh together with the application of Rao-Wilton-Glisson (RWG) and aperture eigenfunctions, respectively, for basis functions achieve the reliable modeling. The efficiency and accuracy of the presented method is verified by available reference results and measurements.
    Microwave Symposium Digest, 2005 IEEE MTT-S International; 07/2005
  • F. Arndt
    [Show abstract] [Hide abstract]
    ABSTRACT: For original article by W. Steyn and P. Meyer see ibid., vol.52, no.6, p.1622-5, June 2004.
    IEEE Transactions on Microwave Theory and Techniques 02/2005; · 2.23 Impact Factor
  • F. Arndt, V. Catina, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: First Page of the Article
    Microwave Conference, 2004. 34th European; 11/2004
  • F. Arndt, V. Catina, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A hybrid mode-matching/finite-element/method-of-moment (MM/FE/MoM) technique is presented for the rigorous analysis of longitudinally corrugated horns. The horn taper is described by the mode-matching method where the cross-section eigenvalue problem is solved by a two-dimensional (2D) finite-element technique. For the exterior horn surface including the radiating aperture of arbitrary shape, the application of the Kirchhoff-Huygens principle yields an expression for the modal admittance matrix based on the electric field integral equation (EFIE). The equations are solved numerically by the method of moments. The eigenvectors of the last waveguide taper section and Rao-Wilton-Glisson (RWG) functions for triangular patches are utilized as basis-functions for the magnetic or electric surface current densities, respectively. The reported hybrid procedure combines the efficiency of the MM method with the flexibility of the FE and MoM techniques. The accuracy and efficiency of the technique are verified by reference measurements; its flexibility is demonstrated with a longitudinally corrugated horn example.
    Antennas and Propagation Society International Symposium, 2004. IEEE; 07/2004
  • F. Arndt, V. Catina, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A hybrid mode-matching (MM) / method-of-moment (MoM) technique is presented for the efficient CAD and optimization of circular combline filters involving more general elements like corrugated circular post and re-entrant resonators. Using the free-space Green's function, the proposed technique combines the high flexibility of the MoM with the efficiency of the MM method. A locally refined adaptive triangular surface mesh and the application of Rao-Wilton-Glisson (RWG) basis functions achieve the reliable modeling of arbitrarily shaped structures. The building blocks are combined by the generalized scattering matrix (GSM) allowing typical MM elements like irises to be efficiently included. The attractive feature of the proposed method is its short computation time (order of a few seconds per frequency point) achieving the full-wave optimization of such filters within reasonable times. The high versatility of the hybrid method is demonstrated at examples of practical interest; its efficiency and accuracy is verified by available measurements.
    Microwave Symposium Digest, 2004 IEEE MTT-S International; 07/2004
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents an overview of the state-of-the-art of hybrid mode-matching (MM)/finite-element (FE)/method-of-moments (MoM)/finite-difference (FD) techniques applied for the rigorous, fast computer-aided design and optimization of waveguide components, combline filters, and coupled horns, as well as of slot arrays, and describes some recent advances. Related aspects involve the inclusion of coaxial and dielectric structures for related filters, the extension to multiports at cross-coupled filters, the rigorous consideration of outer and Inner mutual coupling effects at coupled horn and slot arrays, the application of the multilevel fast multipole algorithm for the more efficient MoM calculation part of horns and horn clusters, and the utilization of the MoM for the design of arbitrarily shaped three-dimensional waveguide elements. The described hybrid techniques combine advantageously the efficiency of the MM method with the flexibility of FE, MoM, and FD methods. Topical application examples demonstrate the versatility of the hybrid techniques; their accuracy is verified by available measurements.
    IEEE Transactions on Microwave Theory and Techniques 02/2004; · 2.23 Impact Factor
  • F. Arndt, V. Catina, J. Brandt
    [Show abstract] [Hide abstract]
    ABSTRACT: A hybrid mode-matching (MM) / method-of-moment (MoM) technique is applied for modeling arbitrarily shaped 3D waveguide structures. Using the free-space Green's function, the attractive feature of this technique is the high flexibility of the MoM combined with the efficiency of the MM method. Its versatility is demonstrated at examples of practical interest, a compensated magic-tee and a combline filter with round posts. The efficiency and accuracy of the method is verified by reference calculations and measurements.
    Microwave Conference, 2003. 33rd European; 11/2003

Publication Stats

2k Citations
122.88 Total Impact Points

Institutions

  • 1981–2009
    • Universität Bremen
      Bremen, Bremen, Germany
  • 1998
    • Bosch GmbH
      Gerlingen, Baden-Württemberg, Germany
  • 1989–1992
    • University of Victoria
      • Department of Electrical and Computer Engineering (ECE)
      Victoria, British Columbia, Canada