@article {09_IJRFMiCAE_Montejo-GaraiRuiz-CruzRebollar_SynthesisSinglyEllipticLadderFilters, title = {Synthesis of Symmetric and Asymmetric Singly-Terminated Elliptic Ladder Filters for Multiplexing Applications}, journal = {International Journal of RF and Microwave Computer-Aided Engineering}, volume = {19}, number = {4}, year = {2009}, month = {July}, pages = {443-452}, abstract = {An extension of the Cauer ladder development for synthesizing singly terminated filters with symmetric and asymmetric responses is presented. Basically, a driving-point immittance including reactive constant elements is carried out in such a way that provides the transmission zeros. The reactive constant elements are introduced into the synthesis for two reasons. The first is to consider the possibility of the asymmetric position of transmission zeros in the real frequency axis. The second one is to obtain canonical forms, i.e. networks with the minimum number of elements in the case of symmetrical responses. To validate the proposed method, a filter with asymmetrical response has been synthesized, comparing different topologies for its use in multiplexers. This fact is illustrated with a Ku-band elliptic response diplexer designed in H-plane rectangular waveguide. {\^A}{\textcopyright} 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.}, keywords = {diplexer, filter synthesis, pole removal, singly terminated, zero-shifting}, issn = {1096-4290}, doi = {10.1002/mmce.20366}, url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/122322557/PDFSTART}, author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M} } @article {05_IEEETMTT_Montejo-GaraiRuiz-CruzRebollarEtAl_Synthesisanddesign, title = {Synthesis and design of in-line N-order filters with N real transmission zeros by means of extracted poles implemented in low-cost rectangular H-plane waveguide}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {53}, number = {5}, year = {2005}, month = {May}, pages = {1636-1642}, abstract = {In this paper, an extension to the extracted pole technique for synthesizing N-order filters with N-transmission zeros at real frequencies is presented. In addition, a new bandpass rectangular waveguide H-plane low-cost configuration filter for high-power low-loss application (patent pending) that implements a filtering function with finite real frequency transmission zeros is proposed. This structure operates as a resonant cavity in transmission at central frequency of the bandpass and simultaneously introduces a controlled transmission zero out of the bandpass. Since every double-controlled electrical behavior cavity introduces a transmission zero, it is possible to introduce as many transmission zeros as the order of the filtering function. In order to validate the synthesis procedure and the new structure, different filters have been designed: a second-order filter with two transmission zeros, a third-order filter with one transmission zero, a fourth-order filter with two transmission zeros, and finally, an eighth-order filter with two transmission zeros. The last two have been manufactured, showing an excellent agreement between the measurement and theoretical simulation.}, keywords = {band-pass filters, double-controlled electrical behavior cavity, eighth-order filter, extracted pole technique, filter synthesis, filtering function, finite real frequency transmission zeros, fourth-order filter, in-line N-order filters, network synthesis, planar waveguides, poles and zeros, rectangular H-plane waveguide, rectangular waveguides, resonant cavity, second-order filter, third-order filter, waveguide filters bandpass rectangular waveguide H-plane filter}, issn = {0018-9480}, doi = {10.1109/TMTT.2005.847053}, url = {http://ieeexplore.ieee.org/iel5/22/30829/01427966.pdf?tp=\&isnumber=\&arnumber=1427966}, author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M and Padilla-Cruz, M J and Onoro-Navarro,A and Hidalgo-Carpintero, I} }