Observations that require large physical instrument dimensions and/or a considerable amount of cr... more Observations that require large physical instrument dimensions and/or a considerable amount of cryogens, as it is for example the case for high spatial resolution far infrared astronomy, currently still face technological limits for their execution from space. The high cost and finality of space missions furthermore call for a very low risk approach and entail long development times. For certain spectral regions, prominently including the mid- to far-infrared as well as parts of the ultraviolet, stratospheric balloons offer a flexible and affordable complement to space telescopes, with short development times and comparatively good observing conditions. Yet, the entry burden to use balloon-borne telescopes is high, with research groups typically having to shoulder part of the infrastructure development as well. Aiming to ease access to balloon-based observations, we present the efforts towards a community-accessible balloon-based observatory, the European Stratospheric Balloon Obser...
In this paper, we propose the implementation of a small refractor telescope inside a 2U-cubesat. ... more In this paper, we propose the implementation of a small refractor telescope inside a 2U-cubesat. The satellite will carry out photometric studies of nearby bright stars aiming the monitoring of exoplanet transits. The telescope consists of an achromatic 80mm-diameter lens working at f/5 coupled to a 1600 × 1220 CCD camera. Resulting images will be sent to the ground using an FM transmitter, operating at a frequency of 437.465MHz and at a rate of 9600 bps. The 2U-cubesat includes an attitude control system which consists of a 3-axis mechanical gyroscope in turn composed of 6 engines acting as reaction wheels. The maximum power consumption of the full system is around 15 Watts. A GPS installed in the communication system will provide the satellite location coordinates. In addition, an optical 8-inch telescope, with f/10 focal ratio, will be used for tracking the satellite from ground.
4 paginas, 7 figuras.-- Trabajo presentado al 25 Simposium Nacional de la Union Cientifica Intern... more 4 paginas, 7 figuras.-- Trabajo presentado al 25 Simposium Nacional de la Union Cientifica Internacional de Radio (URSI) en la sesion III: Antenas III, celebrado en Bilbao (Espana) del 15 al 17 de septiembre de 2010.
Los cansat son conocidos en casi todo el mundo. Su principal objetivo es transmitir a los estudia... more Los cansat son conocidos en casi todo el mundo. Su principal objetivo es transmitir a los estudiantes universitarios los conceptos basicos de diseno y construccion de satelites artificiales. La mayoria de las universidades mas importantes de diversos paises que cuentan con una facultad de ingenieria y ciencias exactas han construido al menos uno de estos dispositivos como actividad extraescolar para sus alumnos, mediante cursos, talleres o a traves de los programas de capacitacion que las agencias espaciales ofrecen para captar las futuras generaciones de ingenieros y cientificos en el area espacial (Walker et al., 2010).
International Journal of Antennas and Propagation, 2017
We propose a model of antenna-coupled microbolometer to be included in an array for receiving and... more We propose a model of antenna-coupled microbolometer to be included in an array for receiving and detecting long wave infrared (LWIR) electromagnetic radiation. The antenna is joined to microstrip bandpass filters thus forming a single metal structure to define the operation frequency band. The antenna and microstrip filters are modeled in aluminum thin film. The microbolometer is modeled with superconducting niobium, all together on a silicon nitride membrane. The squared pixel structure is designed on a support frame of 20 μm in size. Simulation results for this antenna exhibit a frequency range of operation from 27 to 35 THz and is configured for two arrays, one of 10×10 and the other one of 50×50 elements. The device has been simulated by means of the commercial electromagnetic software (HFSS), which is based on the finite elements method. The predicted values for the figures of merit of this microbolometer are as follows: τ=5.8 ns, Rv=5.3×103 V/W, and D⁎ = 2.07×1010 cmHz/W, res...
We propose a bow-tie slot antenna fed by a microstrip to CPW transition to operate in the mm wave... more We propose a bow-tie slot antenna fed by a microstrip to CPW transition to operate in the mm wave-band from 29 to 45 GHz. The measured results exhibit a maximum impedance bandwidth of 43% for VSWR<2, and an average gain of 10 dB. The antenna is suitable for the integration with microstrip circuits and mm-wave MMIC. The antenna is mounted on a mechanical structure with a movable reflector plane which provides the adjustment for the return losses. The whole design facilitates the cooling process when this antenna is used in low temperature experiments.
ABSTRACT We carried out measurements of thermal conductance and thermal contact resistance of two... more ABSTRACT We carried out measurements of thermal conductance and thermal contact resistance of two materials commonly used in low temperature laboratories such as an Electro-Magnetic Interference (EMI) Filter and Stycast 2850 FT epoxy. Both samples were attached on a heat sink made of oxygen-free high thermal conductivity (OFHC) copper and characterized at temperatures between 0.3 K and 4.5 K, using a 3He refrigerator mounted on a pumped 4He cryostat. For the EMI filter we applied a varied input power from 0.25 up to 50 μW to the heater which is soldered to its central pin, whereas for a thin layer of Stycast sandwiched between a copper strap and the heat sink we applied an input power from 10 up to 810 μW. The temperature dependences obtained in each case were $K=3\,{\cdot}\,10^{-5}T^{2.3}~[\frac{\mathrm{W}}{\mathrm{K}}]$ , and $R_{K}=8.4\,{\cdot}\,10^{-3}T^{1.7}\ [\frac{\mathrm{W}}{\mathrm{cm}^{2}\,\mathrm{K}}]$ respectively.
Observations that require large physical instrument dimensions and/or a considerable amount of cr... more Observations that require large physical instrument dimensions and/or a considerable amount of cryogens, as it is for example the case for high spatial resolution far infrared astronomy, currently still face technological limits for their execution from space. The high cost and finality of space missions furthermore call for a very low risk approach and entail long development times. For certain spectral regions, prominently including the mid- to far-infrared as well as parts of the ultraviolet, stratospheric balloons offer a flexible and affordable complement to space telescopes, with short development times and comparatively good observing conditions. Yet, the entry burden to use balloon-borne telescopes is high, with research groups typically having to shoulder part of the infrastructure development as well. Aiming to ease access to balloon-based observations, we present the efforts towards a community-accessible balloon-based observatory, the European Stratospheric Balloon Obser...
In this paper, we propose the implementation of a small refractor telescope inside a 2U-cubesat. ... more In this paper, we propose the implementation of a small refractor telescope inside a 2U-cubesat. The satellite will carry out photometric studies of nearby bright stars aiming the monitoring of exoplanet transits. The telescope consists of an achromatic 80mm-diameter lens working at f/5 coupled to a 1600 × 1220 CCD camera. Resulting images will be sent to the ground using an FM transmitter, operating at a frequency of 437.465MHz and at a rate of 9600 bps. The 2U-cubesat includes an attitude control system which consists of a 3-axis mechanical gyroscope in turn composed of 6 engines acting as reaction wheels. The maximum power consumption of the full system is around 15 Watts. A GPS installed in the communication system will provide the satellite location coordinates. In addition, an optical 8-inch telescope, with f/10 focal ratio, will be used for tracking the satellite from ground.
4 paginas, 7 figuras.-- Trabajo presentado al 25 Simposium Nacional de la Union Cientifica Intern... more 4 paginas, 7 figuras.-- Trabajo presentado al 25 Simposium Nacional de la Union Cientifica Internacional de Radio (URSI) en la sesion III: Antenas III, celebrado en Bilbao (Espana) del 15 al 17 de septiembre de 2010.
Los cansat son conocidos en casi todo el mundo. Su principal objetivo es transmitir a los estudia... more Los cansat son conocidos en casi todo el mundo. Su principal objetivo es transmitir a los estudiantes universitarios los conceptos basicos de diseno y construccion de satelites artificiales. La mayoria de las universidades mas importantes de diversos paises que cuentan con una facultad de ingenieria y ciencias exactas han construido al menos uno de estos dispositivos como actividad extraescolar para sus alumnos, mediante cursos, talleres o a traves de los programas de capacitacion que las agencias espaciales ofrecen para captar las futuras generaciones de ingenieros y cientificos en el area espacial (Walker et al., 2010).
International Journal of Antennas and Propagation, 2017
We propose a model of antenna-coupled microbolometer to be included in an array for receiving and... more We propose a model of antenna-coupled microbolometer to be included in an array for receiving and detecting long wave infrared (LWIR) electromagnetic radiation. The antenna is joined to microstrip bandpass filters thus forming a single metal structure to define the operation frequency band. The antenna and microstrip filters are modeled in aluminum thin film. The microbolometer is modeled with superconducting niobium, all together on a silicon nitride membrane. The squared pixel structure is designed on a support frame of 20 μm in size. Simulation results for this antenna exhibit a frequency range of operation from 27 to 35 THz and is configured for two arrays, one of 10×10 and the other one of 50×50 elements. The device has been simulated by means of the commercial electromagnetic software (HFSS), which is based on the finite elements method. The predicted values for the figures of merit of this microbolometer are as follows: τ=5.8 ns, Rv=5.3×103 V/W, and D⁎ = 2.07×1010 cmHz/W, res...
We propose a bow-tie slot antenna fed by a microstrip to CPW transition to operate in the mm wave... more We propose a bow-tie slot antenna fed by a microstrip to CPW transition to operate in the mm wave-band from 29 to 45 GHz. The measured results exhibit a maximum impedance bandwidth of 43% for VSWR<2, and an average gain of 10 dB. The antenna is suitable for the integration with microstrip circuits and mm-wave MMIC. The antenna is mounted on a mechanical structure with a movable reflector plane which provides the adjustment for the return losses. The whole design facilitates the cooling process when this antenna is used in low temperature experiments.
ABSTRACT We carried out measurements of thermal conductance and thermal contact resistance of two... more ABSTRACT We carried out measurements of thermal conductance and thermal contact resistance of two materials commonly used in low temperature laboratories such as an Electro-Magnetic Interference (EMI) Filter and Stycast 2850 FT epoxy. Both samples were attached on a heat sink made of oxygen-free high thermal conductivity (OFHC) copper and characterized at temperatures between 0.3 K and 4.5 K, using a 3He refrigerator mounted on a pumped 4He cryostat. For the EMI filter we applied a varied input power from 0.25 up to 50 μW to the heater which is soldered to its central pin, whereas for a thin layer of Stycast sandwiched between a copper strap and the heat sink we applied an input power from 10 up to 810 μW. The temperature dependences obtained in each case were $K=3\,{\cdot}\,10^{-5}T^{2.3}~[\frac{\mathrm{W}}{\mathrm{K}}]$ , and $R_{K}=8.4\,{\cdot}\,10^{-3}T^{1.7}\ [\frac{\mathrm{W}}{\mathrm{cm}^{2}\,\mathrm{K}}]$ respectively.
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