Circuit model for coplanar-slotline tees

Coplanar-slotline tees have been used in a number of microwave circuits, although no complete models were available to explain their behavior. In this letter, a new “circuit-model” for a coplanar-slotline tee is presented. The model, based on the separation of coplanar waveguide (CPW) even and odd modes into two different ports, explains the tee's behavior even if CPW air bridges are not used and slotlines are loaded asymmetrically. The new model has been applied to the analysis of the input reflection coefficient of an offset-fed slotline antenna, showing an excellent agreement between simulation and measurement.Peer Reviewe

Circuit Model for mode conversion in coplanar waveguide assymmetric shunt impedances

A new `circuit model' for the conversion between even and odd modes in coplanar waveguide asymmetric shunt impedances is presented. The model is based on the separation of modes into two input and two output ports. In contrast to previous work, it allows a quantitative analysis of the energy exchange between modes.Peer Reviewe

Circuit model for a coplanar-slotline cross

A new 6-port “circuit-model” for coplanar-slotline crosses is presented. The model is based on the separation of the two fundamental Coplanar Waveguide (CPW) modes (even and odd) into different ports. It generalizes previous models since it explains the cross's behavior even if air-bridges are not used and slotlines are loaded asymmetrically. The new model is applied to the analysis of the S-parameters of an asymmetric slotline resonator, and validated through comparison with experimental results up to 40 GHz.Peer Reviewe

Electromagnetic interference prediction in an in-house power-line

Abstract —In this paper a new methodology for the prediction of the conducted-emission propagation in an in-house power- line network is presented. This methodology is based on the modal S -parameter characterization of the devices present in the power-line network, as well as on the modal modeling of branch- line connections. The modal S parameters relate common- and di ff erential-mode waves, and give more information regarding interference propagation. With this methodology, common- and di ff erential-mode attenuations, and modal conversion between common and di ff erential modes can be accurately predicted, which is of great interest for power-line communication devel- opment and conducted-emission mitigation. This methodology is tested by accurately predicting the interference levels up to 100 MHz of an in-house power-line network composed by thermal- magnetic circuit breakers, residual-current circuit breakers, single-phase wires and light bulbs.Peer ReviewedPostprint (author’s final draft

Modelado circuital multimodal de un resonador pasobanda reconfigurable

In this work, we present a simple uniplanar bandpass resonator that can be used for the development of reconfigurable uniplanar filters. The multimodal behaviour of the coplanar waveguide is taken into account for the design of the resonator. We show that a simple multimodal model can be used to represent the proposed structure. Experimental measurements validate the accuracy of the proposed model.Postprint (published version

Compact, wideband impedance tuner using a three-line-microstrip structure

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A novel three-line-microstrip compact impedance tuner is presented. It is based on a multimodal structure wherein six variable capacitances, implemented with two parallel-connected varactors each, create multiple interactions among the three-line-microstrip modes in a reduced circuit area. Experimental results show better-than-70% coverage of the Smith chart in an 85% frequency bandwidth from 1.4 to 3.2 GHz.Peer ReviewedPostprint (author's final draft

Space-for-time substitution and the evolution of submarine canyons in a passive, progradational margin

European Geosciences Union General Assembly 2013, 7-12 April, Vienna, Austria.-- 1 page40% of submarine canyons worldwide are located in passive margins, where they constitute preferential conduits of sediment and biodiversity hotspots. Recent studies have presented evidence that submarine canyons incising passive, progradational margins can co-evolve with the adjacent continental slope during long-term margin construction. The stages of submarine canyon initiation and their development into a mature canyon-channel system are still poorly constrained, however, which is problematic when attempting to reconstruct the development of passive continental margins. In this study we analyse multibeam echosounder and seismic reflection data from the southern Ebro margin (western Mediterranean Sea) to document the stages through which a first-order gully develops into a mature, shelf-breaching canyon and, finally, into a canyon-channel system. This morphological evolution allows the application of a space-for-time substitution approach. Initial gully growth on the continental slope takes place via incision and downslope elongation, with limited upslope head retreat. Gravity flows are the main driver of canyon evolution, whereas slope failures are the main agent of erosion; they control the extent of valley widening, promote tributary development, and their influence becomes more significant with time. Breaching of the continental shelf by a canyon results in higher water/sediment loads that enhance canyon development, particularly in the upper reaches. Connection of the canyon head with a paleo-river changes evolution dynamics significantly, promoting development of a channel and formation of depositional landforms. Morphometric analyses demonstrate that canyons develop into geometrically self-similar systems that approach steady-state and higher drainage efficiency. Canyon activity in the southern Ebro margin is pulsating and enhanced during sea level lowstands. Rapid sedimentation by extension of the palaeo-Millars River into the outermost shelf and upper slope is inferred as the source of gravity flows driving canyon evolution. Canyon morphology is shown to be maintained over the course of more than one fall and rise in sea-level. Our model of canyon evolution is applicable to other passive margins (e.g. Argentine continental margin)Peer Reviewe

Space-for-time substitution and the evolution of submarine canyons in a passive, progradational margin

40% of submarine canyons worldwide are located in passive margins, where they constitute preferential conduits of sediment and biodiversity hotspots. Recent studies have presented evidence that submarine canyons incising passive, progradational margins can co-evolve with the adjacent continental slope during long-term margin construction. The stages of submarine canyon initiation and their development into a mature canyon-channel system are still poorly constrained, however, which is problematic when attempting to reconstruct the development of passive continental margins.peer-reviewe

Circuit model for slotline-to-coplanar waveguide asymmetrical transitions

A new `circuit-model' for slotline-to-coplanar waveguide asymmetrical transitions is presented and applied to the design of slotline resonators. The model, based on the separation of coplanar-waveguide (CPW) modes into two different ports, overcomes limitations of previous models because it explains the transition behaviour even if CPW air-bridges are not used.Peer Reviewe

Circuit model for mode conversion in coplanar waveguide asymmetric series-impedances

A new `circuit model' for converting between even and odd modes in asymmetric series impedances in the ground plane of a coplanar waveguide is presented. The model is based on the separation of modes into two input and two output ports. In contrast to previous work, it enables a quantitative analysis of the energy exchange between modes to be obtained.Peer Reviewe