10 research outputs found
8.2 GHz bandwidth monolithic integrated optoelectronic receiver using MSM photodiode and 0.5 μm recessed-gate AlGaAs/GaAs HEMTs
An 8.2 GHz bandwidth monolithic optoelectronic receiver consisting of an MSM photodiode, a transimpedance amplifier, and a 50 Omega output buffer has been fabricated using an enhancement/depletion 0.5 μm recessed-gate AlGaAs/GaAs HEMT process. Successful operation at data rates up to 10 Gbit/s has been demonstrated
10 Gbit/s monolithic integrated optoelectronic receiver using an MSM photodiode and AlGaAs/GaAs HEMTs
A 10 Gbit/s monolithic integrated optoelectronic receiver has been fabricated with a metal-semiconductor-metal (MSM) photodiode and enhancement/depletion 0.5 μm recessed-gate AlGaAs/GaAs HEMTs. A -3 dB bandwidth of 11.3 GHz has been achieved
1.3 μm monolithic integrated optoelectronic receiver using InGaAs MSM photodiode and AlGaAs/GaAs HEMTs grown on GaAs
The first 1.3 μm monolithic integrated optoelectronic receiver using an InGaAs MSM photodiode and AlGaAs/GaAs HEMTs grown on a GaAs substrate has been fabricated. At each differential output the transimpedance is 26.8 kΩ. The bandwidth of 430 MHz implies suitability for transmission rates up to 622 Mbit/s
CHEOPS: A SPACE TELESCOPE FOR ULTRA-HIGH PRECISION PHOTOMETRY OF EXOPLANET TRANSITS
The CHaracterising ExOPlanet Satellite (CHEOPS) is a joint ESA-Switzerland space mission dedicated to
search for exoplanet transits by means of ultra-high precision photometry whose launch readiness is expected
end 2017. The CHEOPS instrument will be the first space telescope dedicated to search for transits on bright
stars already known to host planets. By being able to point at nearly any location on the sky, it will provide the
unique capability of determining accurate radii for a subset of those planets for which the mass has already been
estimated from ground-based spectroscopic surveys. CHEOPS will also provide precision radii for new planets
discovered by the next generation ground-based transits surveys (Neptune-size and smaller). The main science
goals of the CHEOPS mission will be to study the structure of exoplanets with radii typically ranging from 1 to
6 Earth radii orbiting bright stars. With an accurate knowledge of masses and radii for an unprecedented sample
of planets, CHEOPS will set new constraints on the structure and hence on the formation and evolution of
planets in this mass range. To reach its goals CHEOPS will measure photometric signals with a precision of 20
ppm in 6 hours of integration time for a 9th magnitude star. This corresponds to a signal to noise of 5 for a
transit of an Earth-sized planet orbiting a solar-sized star (0.9 solar radii). This precision will be achieved by
using a single frame-transfer backside illuminated CCD detector cool down at 233K and stabilized within ~10
mK . The CHEOPS optical design is based on a Ritchey-Chretien style telescope with 300 mm effective
aperture diameter, which provides a defocussed image of the target star while minimizing straylight using a
dedicated field stop and baffle system. As CHEOPS will be in a LEO orbit, straylight suppression is a key point
to allow the observation of faint stars. The telescope will be the only payload on a spacecraft platform providing
pointing stability of < 8 arcsec rms, power of 60W for instrument operations and downlink transmission of at
least 1.2GBit/day. Both CHEOPS paylaod and platform will rely mainly on components with flight heritage.
The baseline CHEOPS mission fits within the technical readiness requirements, short development time and the
cost envelope defined by ESA in its first call for S-missions. It represents a breakthrough opportunity in
furthering our understanding of the formation and evolution of planetary systems