Enrique Marquez-Segura

Simulation of negative permittivity and negative permeability by means of evanescent waveguide Modes-theory and experiment

In this paper, the theoretical foundations of the equivalence between waveguide propagation below cutoff and artificial plasmas are carefully analyzed through the derivation of the propagation constants of normal modes in waveguides filled with anisotropic plasmas. The equivalence between waveguide and dielectric plasma proposed by Marquees et al., which is valid for evanescent TE modes, has a dual counterpart for magnetic plasmas and evanescent TM modes. This new equivalence states that a negative magnetic permeability medium can be simulated by means of TM modes below their cutoff frequencies. The need of an anisotropic filling of the waveguide for the equivalence between plasmas and evanescent modes is also highlighted. To exemplify the applicability of this new equivalence, a structure that implements a double-negative medium has been proposed. Full-wave simulations of the proposed structure and measurements from an experimental setup are presented, both of which corroborate the new equivalences validity.

Wire bonded interdigital capacitor

Interdigital capacitors (IDCs) are convenient capacitance devices in microstrip circuits, even if only low capacitance values can be achieved. Nevertheless, undesired resonances degrade their performance when frequency increases. Short circuits across the end of alternate fingers of the IDC improve its high frequency response by eliminating that drawback. Simulated and measured results are presented.

Slot-Coupled Multisection Quadrature Hybrid for UWB Applications

We present a three-section quadrature hybrid based on slot-coupled directional couplers, which operates over a bandwidth from 3.1 to 10.6 GHz. A prototype has been fabricated which exhibits a return loss better than 20 dB, isolation around 20 dB, an amplitude imbalance between output ports of less than plusmn0.75 dB and a phase imbalance between +1deg and -3deg across the 3.1-10.6 GHz band. This design outperforms previously reported results for ultra wide band operation.

Analysis and Design Procedure of Transmission-Line Transformers

Transmission-line transformers are devices used to match RF and microwave devices, to make the conversion balanced-unbalanced, or both things simultaneously. Transmission-line transformers are mandatory at frequencies where traditional magnetic coupling transformers do not operate properly. In this paper, a procedure to design transmission-line transformers with different configurations is presented. The procedure is based on the theoretical analysis of the device and has been validated via experimental study.

Analytical model of the wire-bonded interdigital capacitor

The wire-bonded interdigital capacitor (WBIDC) is an interdigital capacitor with short circuits across the end of alternate fingers that result in an improved frequency response. This paper presents the analytical and circuital models of the WBIDC, which are useful to design and to incorporate into an electromagnetic or circuit analysis computer-aided design program. Design equations of the WBIDC are also presented. The analytical model and design equations have been validated with numerical analysis and experimental work.

High Performance 1.8-18ghz 10-dB Low Temperature Co-Fired Ceramic Directional Coupler

This paper presents a six-section multi-layer asymmetric 10dB directional coupler based on ofiset broadside coupled striplines, using Low Temperature Co-flred Ceramic (LTCC) technology, which operates over a decade bandwidth from 1.8 to 18GHz. It features high performance transitions between the external signal layer and the buried signal layers, as well as a novel mixed flrst section to solve the limitations of the coupler access bends. A prototype was manufactured that exhibits a return loss of better than 15dB, isolation of better than 23dB and a high coupling accuracy of 10:3§0:6dB over the 1.8{18GHz band. This design outperforms previously reported results in terms of bandwidth and shows excellent potential for microwave measurement applications.

Composite Right/Left-Handed Transmission Line With Wire Bonded Interdigital Capacitor

An enhanced composite right/left-handed (CRLH) transmission line (TL) is presented in this letter. This TL, designed in microstrip technology, is implemented by means of a new improved interdigital capacitor (IDC), the so-called wire bonded IDC (WBIDC). The use of the WBIDC broadens the frequency band where the CRLH TL can be considered as a TL. A conventional 70-Omega CRLH TL (using IDCs) has been compared, by full-wave simulation and measurements, with its enhanced counterpart (using WBIDCs). In addition, this enhanced CRLH TL has been used to design a CRLH diplexer which presents several advantages over standard CRLH coupled lines (using IDCs). The diplexer response has been verified by means of a full-wave electromagnetic solver

ARTIFICIAL TRANSMISSION LINE WITH LEFT/RIGHT-HANDED BEHAVIOR BASED ON WIRE BONDED INTERDIGITAL CAPACITORS

Abstract—A novel artificial transmission line with right/left-handed behavior is presented in this paper. The unit cell of the new artificial line consists of one series and one shunt wire bonded interdigital capacitors. When wire bonded interdigital capacitors are used, the artificial line has a wider frequency band of operation. A combined analytical-graphical design method of the proposed artificial transmission line is also presented. The method has been assessed with the help of an electromagnetic solver based on the method of moments, and experimental work.

Exact Analysis of the Wire-Bonded Multiconductor Transmission Line

In this paper, the exact model of a multiconductor transmission line with bonding wires is presented. The model is based on the multiport admittance matrix, and is valid for any number of conductors in the structure. The model shows how to compute the two-port admittance matrix of the wire-bonded structure with direct application to the wire-bonded interdigital capacitor. The model has been validated by means of method-of-moments-based numerical simulation and by experimental work.

Generalized Analytical Design of Broadband Planar Baluns Based on Wire-Bonded Multiconductor Transmission Lines

A novel generalized design procedure of broadband planar baluns based on wire-bonded multiconductor transmission lines (MTL) is presented hereby based on analytical equations. The proposed balun consists of two parts. The flrst one is an in-phase power divider, which equally splits the input power through its two outputs. The later are two MTLs with wire bonding between alternate conductors conflgured to introduce +90 and i90 degrees phase shift respectively, so that the balanced output signal has a 180 degree phase difierence. In that sense, new closed-form design equations in order to calculate the design parameters of both multiconductor elements are obtained. These equations allow the proper dimensions of both MTLs to be computed irrespective of both the number of conductors and the coupling factor, and therefore, to determine the performance of the balun. The design procedure for wire-bonded MTL baluns has been assessed by means of full-wave electromagnetic simulations and by experimental work. In addition, the very good agreement between the theoretical results and measurements makes possible to deflne a time-saving design methodology.