Characteristic planes of microstrip and unilateral finline tee-junctions

A unique set of reference planes which enters into the description of a three port E or H-plane tee-junction are its characteristics planes. These planes correspond to the positions of a short circuit at one typical port that will decouple a second port from one input port. The purpose of this paper is to establish these planes in the cases of microstrip and unilateral finline circuits. This is done in each case for a number of different geometries. The spacing between the first two characteristic planes across the junction is 360 deg. In the case of the H-plane tee junction, it is 180 deg in the case of the E-plane geometry.The authors would like to thank the Spanish Ministry of Science and Innovation (MICINN) by the financial support provided through project TEC2011-29126-C03-01 and CONSOLIDER-INGENIO 2010 CSD2008-00068

Inverted re-entrant turnstile waveguide circulator using prism resonator with arbitrary orientation

The waveguide re-entrant or inverted re-entrant turnstile circulator relies for its operation on either a quarter wave long cylindrical or prism resonator mounted on either a circular or an equilateral platform with its open face separated from the top waveguide wall by a suitable gap. The adjustment of the prism geometry, the main endeavour of this paper, is characterized by two degrees of freedom. One degree of freedom is the orientation of the prism inside the junction with respect to a typical waveguide feed. The others are the aspect ratio of the gyromagnetic resonator and the choice of platform or piston. The agreement between some calculations based on a Finite Element (FE) engine and experiment is excellent. The work undertaken here indicates that the preferred geometry is that for which the platform has the crosshairs section of the resonator.The authors would like to thank Apollo Microwave, Montreal, for the experimental facilities. “This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project TEC2014-58341-C4-1-R, with FEDER co-funding”

Observation of a Chiral State in a Microwave Cavity

A microwave experiment has been realized to measure the phase difference of the oscillating electric field at two points inside the cavity. The technique has been applied to a dissipative resonator which exhibits a singularity -- called exceptional point -- in its eigenvalue and eigenvector spectrum. At the singularity, two modes coalesce with a phase difference of $\pi/2 .$ We conclude that the state excited at the singularity has a definitiv chirality.Comment: RevTex 4, 5 figure

Compensation of the impact of low-cost manufacturing techniques in the design of E-plane multiport waveguide junctions

In this work, a full-wave tool for the accurate analysis and design of compensated E-plane multiport junctions is proposed. The implemented tool is capable of evaluating the undesired effects related to the use of low-cost manufacturing techniques, which are mostly due to the introduction of rounded corners in the cross section of the rectangular waveguides of the device. The obtained results show that, although stringent mechanical effects are imposed, it is possible to compensate for the impact of the cited low-cost manufacturing techniques by redesigning the matching elements considered in the original device. Several new designs concerning a great variety of E-plane components (such as right-angled bends, T-junctions and magic-Ts) are presented, and useful design guidelines are provided. The implemented tool, which is mainly based on the boundary integral-resonant mode expansion technique, has been successfully validated by comparing the obtained results to simulated data provided by a commercial software based on the finite element method.All the data necessary to understand, evaluate, replicate, and generate the figures and results presented in this paper have been included in the present manuscript. A full-wave custom code and the commercial software Ansys HFSS have been used to generate the simulated results provided by the authors. This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under the Research Projects TEC2013-47037-C5-1-R and TEC2013-47037-C5-4-R.San Blas Oltra, ÁA.; Roca, JM.; Cogollos Borras, S.; Morro, JV.; Boria Esbert, VE.; Gimeno Martinez, B. (2016). Compensation of the impact of low-cost manufacturing techniques in the design of E-plane multiport waveguide junctions. Radio Science. 51(6):619-628. https://doi.org/10.1002/2016RS006027S61962851