Synthesis considerations for acoustic wave filters and duplexers starting with shunt resonator

This project presents a synthesis procedure for acoustic wave ladder filters and duplexers taking also into consideration the case of networks whose first resonator is in shunt configuration. The feasibility of these networks in terms of the phase of the filter function is investigated and a lowpass synthesis view of the issues that might arise is presented providing different approaches for designers to achieve feasible networks.Aquest projecte presenta una metodologia de síntesi de filtres i duplexors d'ona acústica en topologia d'escala tenint també en compte el cas de les xarxes que comencen amb un ressonador en paral·lel. La viabilitat d'aquestes xarxes s'investiga en termes de la fase de la funció de filtrat i s'aporta una visió de síntesi pas baix de les limitacions que poden aparèixer, proveint alhora diferents solucions perquè els dissenyadors puguin obtenir xarxes viables

Microwave microphone using a general purpose 24 GHz FMCW radar

The usage of a commercial 24 GHz frequency-modulated continuous-wave (FMCW) radar sensor to retrieve sound signals is investigated in this article. Thanks to the great phase measurement capabilities of current radar sensors, low-frequency audio signals can be recovered by measuring the vibrations they induce in objects due to their pressure wave nature. To prove the concept, a sound emitted by a speaker is recorded by analysing the small-scale displacement of a reflective surface using a radar sensor originally devised for automotive and UAV applications at the 24 GHz ISM band

Star-shaped wheel for mechanical micro-Doppler modulation

This letter investigates the possibility of using deliberated geometries for rotating targets, which may improve the detectability and classification by means of its micro-Doppler signature. Beyond the signature provided by the rotation rate of the target, every particular geometry leads to specific and unique modulation waveforms that increase the information related to this target. Different star-shaped wheels with particular geometries have been designed demonstrating different reflection characteristics and modulation waveforms. The signature of these rotating star-shaped wheels has been measured in an anechoic chamber using a general-purpose 24 GHz frequency-modulated continuous wave (FMCW) radar platform and a detection algorithm based on the derivative of the cross-correlation is proposed to validate the proposed approach

Planck-LFI 44-GHz back end module

This work describes the principle of operation, assembly and performance of one branch of the 44 GHz back end module (BEM) for the Planck low frequency instrument (LFI). This subsystem constitutes a fully representative branch of the qualification-model version (QM). It includes waveguide to microstrip transition, GaAs pseudomorphic high electron mobility transistor (PHEMT) low noise amplifiers (LNA), bandpass filter, square-law detector and dc amplifier. The fundamentals of the design of the RF part are described and all of the components have been tested individually before integration. Using single tone and wideband noise stimuli, the output voltage has been measured for several input powers, in order to obtain the sensitivity factor of the complete BEM. The effective bandwidth and the equivalent noise temperature have been calculated from the measurements, taking into account the frequency dependence on the noise source and the BEM. Finally, the low frequency output power spectrum has been obtained and a maximum 1/f knee frequency around 200 Hz has been measured with a 3 dB output signal video bandwidth above 50 KHz.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

Very Low-Noise Differential Radiometer at 30 GHz for the PLANCK LFI

The PLANCK mission of the European Space Agency is devoted to produce sky maps of the cosmic microwave background radiation. The low-frequency instrument is a wide-band cryogenic microwave radiometer array operating at 30, 44, and 70 GHz. The design, test techniques, and performance of the complete differential radiometer at 30 GHz are presented. This elegant breadboard 30-GHz radiometer is composed of a front-end module (FEM) assembled at the Jodrell Bank Observatory, Cheshire, U.K., and a back-end module assembled at the Universidad de Cantabria, Cantabria, Spain, and Telecomunicacio/spl acute/, Universitat Polite/spl acute/cnica de Catalunya, Barcelona, Spain. The system noise temperature was excellent, mainly due to the very low noise performance of the FEM amplifiers, which achieved an average noise temperature of 9.4 K.Peer Reviewe

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

TERASENSE: THz device technology laboratory: final summary

The use of THz frequencies, particularly W and G band allows reaching higher resolution and deeper penetration in emerging applications like imaging, sensing, etc. The development of those new applications lays on reliable technologies, background of expertise and know-how. The CDS2008-00068 TERASENSE CONSOLIDER project has given the opportunity to extent upwards in frequency the previous background of the microwaves research group partners. This article summarizes the developments of the TERASENSE work package “THz Device Technology Laboratory”.This work was supported by the Spanish Ministerio de Ciencia e Innovación through the CONSOLIDER-INGENIO 2010 program reference CSD2008-00068 TERASENSE

TERASENSE: THz device technology laboratory

The use of THz frequencies, particularly W and G band allows reaching higher resolution and deeper penetration in emerging applications like imaging, sensing, etc. The development of those new applications lays on reliable technologies, background of expertise and know-how. The CDS2008-00068 TERASENSE CONSOLIDER project has given the opportunity to extent upwards in frequency the previous background of the microwaves research group partners. This article summarizes the developments of the TERASENSE work package “THz Device Technology Laboratory”