2,767 research outputs found
A Fully-Integrated Reconfigurable Dual-Band Transceiver for Short Range Wireless Communications in 180 nm CMOS
© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.A fully-integrated reconfigurable dual-band (760-960 MHz and 2.4-2.5 GHz) transceiver (TRX) for short range wireless communications is presented. The TRX consists of two individually-optimized RF front-ends for each band and one shared power-scalable analog baseband. The sub-GHz receiver has achieved the maximum 75 dBc 3rd-order harmonic rejection ratio (HRR3) by inserting a Q-enhanced notch filtering RF amplifier (RFA). In 2.4 GHz band, a single-ended-to-differential RFA with gain/phase imbalance compensation is proposed in the receiver. A ΣΔ fractional-N PLL frequency synthesizer with two switchable Class-C VCOs is employed to provide the LOs. Moreover, the integrated multi-mode PAs achieve the output P1dB (OP1dB) of 16.3 dBm and 14.1 dBm with both 25% PAE for sub-GHz and 2.4 GHz bands, respectively. A power-control loop is proposed to detect the input signal PAPR in real-time and flexibly reconfigure the PA's operation modes to enhance the back-off efficiency. With this proposed technique, the PAE of the sub-GHz PA is improved by x3.24 and x1.41 at 9 dB and 3 dB back-off powers, respectively, and the PAE of the 2.4 GHz PA is improved by x2.17 at 6 dB back-off power. The presented transceiver has achieved comparable or even better performance in terms of noise figure, HRR, OP1dB and power efficiency compared with the state-of-the-art.Peer reviewe
High-gain self-steering microwave repeater, volume 1 Final engineering report, Jan. 1966 - Apr. 1969
Engineering model of high gain self steering microwave transponder and application to satellite communication link
Generic concepts of the automated multifunctional receiver
Automated multifunctional receiver for space tracking and data acquisition network, manned space flight network, and deep space networ
Automatic beam alignment in the Garching 30-m prototype of a laser-interferometric gravitational wave detector
We describe a system for complete autoalignment of a suspended, power-recycled Michelson interferometer. All ten angular degrees of freedom are controlled by servo systems, thus ensuring optimal interference and fixing all beams in space. The methods and results are applicable to laser-interferometric gravitational wave detectors, and possibly also to other types of sensitive interferometers
A TDM synchronization system for multiple access satellite communication
Time Division Multiple Access /TDMA/ system for satellite communication with ground station syste
Theory of phaselock techniques as applied to aerospace transponders
Phaselock techniques as applied to aerospace transponder
Magnetometric techniques for the measurement of initial susceptibility and for non-contact sensing of displacement
PhD ThesisPart 1 of the thesis describes a new instrument that simultaneously
measures the real magnetic susceptibility X' and the imaginary magnetic
susceptibility X". The instrument measures the temperature dependences of
X' and X" in rock samples between 16°C and 800°C; natural developments are
working down to -200°C and measuring the anisotropy of susceptibility.
The instrument's heart is a tuned circuit driven at its natural frequency
by a 5MHz crystal oscillator. The tuned circuit's inductance is a sample
coil that encloses-a furnace. The random noise level in the signal for X'
is 7.4 x l0-13 m3 r. m. s., the noise level in the signal for X" is 2x 10 ^12
m3 r. m. s. Sample volumes are 0.1 cm3 or less.
Equations describing the instrument are derived and verified, particular
attention is paid to the sample coil. Circuit diagrams are included.
Some results are presented and equations that broadly describe the observed
temperature dependences of X' and X" are developed. Some methods for
substantially improving the instrument's performance are outlined.
Part 2 of the thesis describes a new method for non-contact sensing
of displacement. A magnet is mounted on the object whose displacement is
to be measured. The magnet's field is sensed and fed to a 6502 microprocessor
programmed to display the distance between the magnet and the
sensor; intervening barriers with a permeability very close to unity do not
affect the readings. The accuracy is better than 2.0% of full scale
deflection (FSD) over the useful range of 250 mm and better than 0.1%
FSD over a range of 110 mm. The magnet's volume is 4.00 mm3 and the
moment is 3.1 x 10-7 Vbm. Circuit diagrams are presented and a complete software
listing is included, the design will work with any magnet and
magnetometer.
There are directions for greatly improving the instrument's
performance.Natural Environment Research Council
Goddard range and range rate system Design evaluation report
Tracking and telemetry data at VHF and S band frequencies from spacecraft for GRARR syste
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