Amplifier having digital micro processor control apparatus
AssigneeNortel Networks Limited
InventorsGraham Dolman, Peter King, Andrew John Booth
Life of this patent
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Abstract
This invention relates to an amplifier having digital micro-processor control apparatus and, in particular, to a high frequency power amplifier that includes a micro-processor control system to accurately regulate the operating point of the various amplifying elements in the high frequency power amplifier. The basic amplifier circuitry consists of a micro-controller, a variable voltage attenuator (VVA), a digital to analogue converter and an EEPROM. The EEPROM provides a lookup table which is read by the micro-controller, which then writes to the digital to analogue converter to set the control voltage to the variable voltage attenuator.
Claims16
An amplifier circuit having an amplifying element, a bias circuit coupled to an input of said amplifying element, and a microcontroller arranged to control the bias circuit according to predetermined criteria and determined input power to the element in order to control the amplifying element gain in order to compensate for the internal heating effects of said amplifying element, the compensation taking into account thermal lag in the amplifying element to provide more accurate control during dynamic changes in thermal effect.
A method of operating an amplifying element in order to compensate for internal heating effects for different input signal levels, said method comprising:
- determining input signal level to said amplifying element;
- and
- controlling bias conditions of said element dependent on said input level and predetermined criteria while taking into account thermal lag in the amplifying element to provide more accurate control during dynamic changes in thermal effect.
Dependencies are inferred from the claim text.