摘要:
The present invention relates to an exponential function generator which is realized with only CMOS element without BJT element, not limited by the physical properties of the element or a square circuit, and not complicated in its configuration, and a variable gain amplifier using the same. The exponential function generator includes a voltage-current converter, 1st to nth curve generators for mirroring the current from the voltage-current converter, outputting a current adjusted according to a predetermined ratio, and an output end for outputting the sum of the current from the 1st to nth curve generators. The exponential current generator is configured to generate the current exponentially adjusted according to the control voltage.
摘要:
Disclosed herein is a receiver for down-conversion of a dual band. The receiver can down convert radio frequency signals of two different bands into a desired IF signal using only one voltage controlled oscillator (VCO), by dividing the output of the VCO into a predetermined ratio with a divider. The VCO outputs a desired oscillating frequency for conversion of the first-band RF signal into the IF signal, and the divider divides the desired oscillating frequency in a predetermined ratio to output a frequency for conversion of the second-band RF signal into the IF signal. Thus, the receiver can be formed on one silicon substrate.
摘要:
The invention relates to a feedback or feedforward type variable gain wideband amplifier. The variable gain wideband amplifier includes a feedback-type inversion amplifier circuit 310 for amplifying input Vin, a feedback-type non-inversion amplifier circuit 320 for amplifying input Vin, a power source circuit 330 for controlling the gain of the non-inversion amplifier circuit 320 and a load circuit 340 connected between a junction of output terminals of the inversion and non-inversion amplifier circuits 310 and 320 and power voltage potential VDD to control the gain of the amplifier circuits 310 and 320. The variable gain wideband amplifier of the invention is feedforward type, and outputs signals from the inversion and non-inversion amplifier circuits 310 and 320 via a single output terminal in order to attenuate third order intermodulation frequency IM3 generated from the amplifier circuits 310 and 320. Then, predetermined frequencies f1 and f2 included in the input signal are amplified.