Patent ID: 6118342
Filing Date: 2000-09-12
Classification: H03F,H03G

Abstract:
A system precisely controlling the gain of an RF amplifier over temperature comprising:an RF carrier circuit comprising the RF carrier amplifier and a PIN diode attenuator having a plurality of PIN diodes;an interface circuit comprising a current control operational amplifier that outputs a current to control the amount of attenuation provided by the PIN diodes and a temperature sensor operational amplifier that regulates the current control operational amplifier to output the same amount of current over varying operating temperatures; andan RF gain control circuit comprising a digital to analog converter, circuitry coupled between the digital to analog converter and the current control operational amplifier and temperature sensor operational amplifier, that adjusts the amount of attenuation provided by the PIN diodes, that generates a reference voltage for the digital to analog converter that varies with the output voltage produced by the temperature sensor operational amplifier, and wherein the digital to analog converter generates a precise voltage that is converted to a precise current by the current control operational amplifier to precisely control the gain of the RF carrier amplifier.