Desarrollo de tecnología Bulk Acoustic Wave

El creciente uso de dispositivos móviles y el gran avance en la mejora de las aplicaciones yEl creixent ús de dispositius mòbils i el gran avanç en la millora de les aplicacions i sistemesThe increasing use of mobile devices and the breakthrough improvement in applications an

Nonlinear performance characterization in an eight-pole quasi-elliptic bandpass filter

In this work we predict the nonlinear behaviour of an eight-pole quasi-elliptic bandpass high temperature superconducting (HTS) filter with an equivalent circuit extracted from intermodulation measurements performed at the centre of the filter passband. We present measurements that show that the equivalent circuit is able to predict the intermodulation products produced by the filter when driven by two in-band or out-of-band sinusoidal signals. Numerical techniques based on harmonic balance are used to extract the elements of the equivalent circuit and to simulate its nonlinear performance.Peer Reviewe

Analysis of dielectric-loaded cavities for characterization of the nonlinear properties of high temperature superconductors

This work describes and compares two alternative methods of analyzing dielectric-loaded cavities for measurement of intermodulation distortion in HTS films. One of them is based on assuming a specific type of HTS nonlinearities and developing theoretical equations based on them. The second is based on a numerical approach that can be applied to many types of nonlinearities. Both methods are shown to work on measured data of representative HTS films.Peer Reviewe

A general approach for the calculation of intermodulation distortion in cavities with superconducting endplates

We report on a general procedure to calculate intermodulation distortion in cavities with superconducting endplates that is applicable to the dielectric-loaded cavities currently used for measurement of surface resistance in high-temperature superconductors. The procedure would enable the use such cavities for intermodulation characterization of unpatterned superconducting films, and would remove the uncertainty of measuring intermodulation on patterned devices, in which the effect of patterning damage might influence the outcome of the measurements. We have verified the calculation method by combining superconducting and copper endplates in a rutile-loaded cavity.Peer Reviewe

Nonlinear Distortion in a 8-Pole Quasi-Elliptic Bandpass HTS Filter for CDMA System

High Temperature Superconductor materials are known to produce intermodulation and other nonlinear effects which may restrict their use in wireless communication systems. Quantifying this degradation is crucial in determining if the use of HTS filters in the receiver is beneficial. In this work we use an approach for representing the HTS filter nonlinear equivalent circuit and simulating its performance. We have tested the approach on a planar, 8-pole quasielliptic (QE) filter, showing agreement between simulations and measurements of intermodulation products (IMD). The nonlinear equivalent circuit is then used to predict the nonlinear behavior of the filter and its effects on system parameters when it is subject to broadband signals like those used in wireless communication systems.Peer Reviewe

General Equations for the Induced Phase Shift in Resonant Electro-Optic Modulators

We derive general equations to calculate the electrooptically induced optical phase shift in resonantly enhanced modulators. The equations are useful in designing modulator electrodes with optimal length and optimal mismatch between electrical and optical velocities. We demonstrate the existence of an optimal velocity mismatch depending on the resonant mode used.Peer Reviewe

Performance Projection of Electro-Optical Modulators for Radio-Over-Fiber in 2 GHz Cryogenic Front-End Receivers

We present the design of a Y-Ba-Cu-O on LiNbO/sub 3/ cryogenic electro-optical modulator for analog 2 GHz applications. A resonant configuration of coplanar electrodes is considered, showing improvements with respect to both resonant Au electrodes and to traveling-wave electrodes, even beyond the traveling-wave theoretical maximum performance limit. The optimized layout is presented featuring a reduced length of 8.26 mm.Peer Reviewe

Sub-millimiter wave receivers

In this article a review is carried out of how technological aspects are affecting the system configuration of a sub-millimeterwave receiver for imaging applications. Throughout the discussion we will emphasize the role that the Schottky diode plays in this type of applications

Configuraciones para radiómetro de potencia total en banda W

Different topologies of total power radiometer in W band are presented and compared in terms of effective bandwidth and sensitivity. Both, commercially available and own designed MMICS are considered. A simulation procedure is proposed to emulate in harmonic balance the application of wide bandwidth noise. Technological issues of the implementation are addressed

Desarrollo de tecnología Bulk Acoustic Wave

El creciente uso de dispositivos móviles y el gran avance en la mejora de las aplicaciones yEl creixent ús de dispositius mòbils i el gran avanç en la millora de les aplicacions i sistemesThe increasing use of mobile devices and the breakthrough improvement in applications an