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.
Design of an integrated demodulator for a 13.56 MHz RFID reader
An integrated demodulator for 13.56 MHz RFID Reader is designed in 0.18um CMOS technology. The design is mainly composed of a detector and an amplifier. The chip operates at 2V p-p and occupies an area of 0.536 mm2. Results show smaller ripple (≪0.2%) and faster settling time than that of existing systems.
A New Integrated High-Performance AM Receiver for Car Radio
A new type of monolithic AM receiver has been designed and integrated in a conventional 40OMHz-fT bipolar process. Adjustments and band switches are completely eliminated, and production costs can be reduced considerably thanks to the unconventional approach, which uses an upconversion system.