An Integrated IF Amplifier and Detector for an A.M. Upconversion Radio
This paper presents a monolithically integrated IF amplifier and envelope detector for an AM upconversion car-radio receiver. This receiver is intended for the reception of the long-wave and medium-wave frequency bands and uses an intermediate frequency of 10.7 MHz. Specific requirements resulting from the upconversion concept will be illustrated and the basic considerations for maximization of the signal-to-noise ratio as a function of the input signal level will be given. Furthermore, a new method will be presented for fixing the signal levels and the AGC speed in the amplifier. The amplifier uses two emitter-driven variable-gain pairs alternated by negative-feedback current amplifiers. It has an AGC range of 90 dB and a gain of 66 dB. The audio output level is constant within 0.2 dB over the full controll range. A cross-quad compensated envelope detector is driven at a level as low as 30 mV and shows less than 3-percent distortion at a modulation depth of 80 percent.
A Low Ripple Low Power CMOS Demodulator for 13.56 MHz RFID Reader
This study concerns about a high frequency spectrum companionable CMOS demodulator design for RFID application. In this paper,implementation of a demodulator is described for 13.56 MHz RFID Reader employing 0.18um CMOS technology, showing smaller ripple(<0.3) than that of existing systems. The designeddemodulator consists of an amplifier and a detector, which consumes a power of 51.4 uWatt at 1 V biasing. Index Terms – ASK, RFID Reader, Demodulator, CMOS, Ripple.
Perturbed angular correlation study of a haptenic molecule.
The angular correlation of the 173-247 keV gamma-ray cascade after the electron-capture decay of (111)In is strongly perturbed when the 1-p-nitrophenyl-ethylenediaminetetraacetate chelate of (111)In(8+) is added to a solution containing rabbit antibody to dinitrophenyl groups. The radioactive chelate can be displaced by the addition of dinitrophenyllysine or unlabeled chelate. The average association constant between the antibody and the labeled chelate has been estimated from perturbed angular correlation measurements; this value is compared to the results of equilibrium dialysis. These experiments provide good evidence that information concerning macromolecular behavior can be obtained from perturbed angular correlation experiments that use chemically specific labels.