@article { , title = {Fringing effects in re-entrant and Inverted re-entrant turnstile waveguide junctions using cylindrical resonators.}, abstract = {One waveguide network is a 5-port turnstile junction consisting of three H-plane waveguides with a circular quarter wave long resonator on its axis, open circuited at one end and short circuited at the other. It is readily converted to a turnstile 3-port circulator by replacing the dielectric resonator by a gyromagnetic one and closing 2 of the 5 ports. Another network that may be reduced to a 3-port circulator is a 7 port turnstile junction containing a pair of similar coupled resonators or a half wave long arrangement open circuited at each end. The introduction of suitable symmetry planes in the latter two geometries suggests that all three have, in the absence of any fringing effects, the same centre frequency. In practice, however, this is not so. This paper employs an FE process to investigate this assumption in the cases of re-entrant and inverted re-entrant resonators. One conclusion of this work is that a FE or similar numerical tool is mandatory for the adjustment of such a degree-2 circuit.}, doi = {10.1049/iet-map.2010.0393}, eissn = {1751-8733}, issn = {1751-8725}, note = {Note: This paper is a postprint of a paper submitted to and accepted for publication in IET Microwave Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library School: sch\_eng}, pages = {1109-1115}, publicationstatus = {Published}, publisher = {Institution of Engineering and Technology (IET)}, url = {http://researchrepository.napier.ac.uk/id/eprint/5324}, volume = {5}, keyword = {621.3 Electrical & electronic engineering, TK Electrical engineering. Electronics Nuclear engineering, waveguide network, five-port turnstile junction, H-plane waveguides, turnstile threeport circulator, re-entrant and inverted re-entrant resonators;}, year = {2011}, author = {Helszajn, Joseph and Sharp, John} }