Tech Portfolio

A high altitude lidar system propagates a beam of laser pulses through clearings in a cloud formation which reflects off the surface of the earth thereby providing first earth surface returns and reflections towards the base of a cloud that again reflects the pulses back towards the earth surface to be reflected again to provide cloud base returns.

A wet and vapor acid etching method releases a microelectromechanical systems (MEMS) structure from a substrate by dissolving a sacrificial layer disposed between the MEMS and the substrate. The sacrificial layer may be a silicon dioxide (SiO2) layer having a field portion over which the MEMS does not extend and a support portion over which the MEMS does extend.

A charging and discharging method for lithium-ion and lithium-polymer batteries determines overcharged, undercharged, normal and degraded operating conditions and adjusts a recharge fraction of recharge capacity to discharge capacity for improving battery life while maintaining the battery cells at a high charge state.

A feed-forward linearization of a traveling wave tube amplifier linearizes the transfer function of the tube through a linearization voltage derived at baseband from the instantaneous amplitude of the input signal to control the cathode voltage causing induced phase modulation to offset the normal amplitude modulation to phase modulation conversion distortion.

An improved Gaussian minimum shift keying (GMSK) carrier tracking loop operating at baseband takes advantage of the orthogonality of precoded data GMSK signals and Laurent filtering to provide a carrier phase error signal generated at baseband for carrier phase derotation of the received GMSK signal.

A high frequency anharmonic oscillator provides a broad band chaotic oscillation with a noise-like spectra. The oscillator output signal is suitable for modulation by data providing for improved secure communication. The chaotic oscillator is based upon a forced second order Duffing equation that is tolerant of delay in the feedback path for high frequency operation.