Abstract:
Provided is an apparatus and method for measuring IQ imbalance, and in particular, is an apparatus and method for measuring IQ imbalance for an optical receiver. The apparatus for measuring IQ imbalance for an optical receiver includes a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver, a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals, and a calculating unit calculating IQ imbalance for the optical receiver with reference to the Lissajous figure.
Abstract:
Disclosed are a laser radar system and a method for acquiring an image of a target, and the laser radar system includes: a beam source to emit the laser beam; a beam deflector disposed between the beam source and the target, and configured to deflect the laser beam emitted from the beam source in a scanning direction of the target as time elapses; and an optical detector configured to detect the laser beam reflected from the target, which is provided a plurality of beam spots having a diameter DRBS; and a receiving optical system disposed between the target and the optical detector and configured to converge the laser beam reflected from the target, and the optical detector includes a detecting area having a diameter DDA that satisfies an equation of √{square root over (/2)}×PRBS+2×DRBS≦DDA≦2×Dlens and an equation of (4/π)×λ×F_number
Abstract:
Disclosed are a laser radar system and a method for acquiring an image of a target, and the laser radar system includes: a beam source to emit the laser beam; a beam deflector disposed between the beam source and the target, and configured to deflect the laser beam emitted from the beam source in a scanning direction of the target as time elapses; and an optical detector configured to detect the laser beam reflected from the target, which is provided a plurality of beam spots having a diameter DRBS; and a receiving optical system disposed between the target and the optical detector and configured to converge the laser beam reflected from the target, and the optical detector includes a detecting area having a diameter DDA that satisfies an equation of √{square root over (2)}×PRBS+2×DRBS≦DDA≦2×Dlens and an equation of (4/π)×λ×F_number
Abstract:
Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measurable range.
Abstract:
A high electron mobility transistor includes a substrate including a first surface and a second surface facing each other and having a via hole passing through the first surface and the second surface, an active layer on the first surface, a cap layer on the active layer and including a gate recess region exposing a portion of the active layer, a source electrode and a drain electrode on one of the cap layer and the active layer, an insulating layer on the source electrode and the drain electrode and having on opening corresponding to the gate recess region to expose the gate recess region, a first field electrode on the insulating layer, a gate electrode electrically connected to the first field electrode on the insulating layer, and a second field electrode on the second surface and contacting the active layer through the via hole.
Abstract:
An apparatus for measuring performance of a coherent optical receiver includes a beam splitter splitting light into first and second paths, a first optical modulator modulating the first path light, a variable optical attenuator controlling an optical power of the first optical modulator, a first polarization controller transmitting a signal controlling polarization of an output of the variable optical attenuator to the coherent optical receiver, a second optical modulator modulating the second path light, a variable optical delay line delaying time of an output of the second optical modulator, a second polarization controller transmitting a signal controlling polarization of an output of the variable optical delay line to the coherent optical receiver, a network analyzer measuring performance of the coherent optical receiver and controlling the optical modulators, and a controller transmitting a control signal to the optical modulators.