Attenuator Network Gain Control for Continuous Transmit Power
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Solution Overview
Problem
Conventional transmitter systems face challenges in accurately controlling output power over a wide dynamic range due to factory calibration requirements and temperature variations, leading to gain discontinuities in mobile communication devices.
Innovation Solution
A gain control system utilizing a network of attenuators with fixed and variable gain elements, power detectors, and a compensator to adjust the variable attenuation and minimize power discontinuities, enabling continuous and accurate power level control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If factory calibration is used to adjust attenuation stages, then transmit power step tolerance can be met under ideal conditions, but the system fails when operating under changing temperature and environmental conditions
Solution Approach 1:
The patent implements a feedback mechanism where the output signal from the attenuator network is fed back through power detectors and comparators to generate error signals. These error signals are used to dynamically adjust the attenuation stages, creating a closed-loop control system that automatically compensates for temperature variations and maintains accurate transmit power step tolerance without requiring factory calibration adjustments.
Solution Approach 2:
The patent changes the operating parameters of the attenuation network by introducing dynamically adjustable attenuation values controlled by digital-to-analog converters. Instead of fixed factory-calibrated attenuation stages, the system uses programmable attenuation values that can be adjusted in real-time based on environmental conditions, thereby maintaining performance across varying temperatures.
2Adaptability or versatility
If multiple independent variable attenuators are used to control power over wide dynamic range, then power control capability is improved, but gain discontinuities and calibration complexity increase
Solution Approach 1:
The patent merges multiple independent variable attenuators into a unified attenuator network with centralized control. Instead of treating each attenuator stage independently requiring separate calibration, the patent combines them into an integrated system where a single control mechanism manages all stages, reducing calibration complexity while maintaining the ability to control power over a wide dynamic range.
Solution Approach 2:
The patent creates a universal control mechanism that serves multiple attenuator stages simultaneously. The error signal generation and attenuation control system functions universally across all power levels and temperature conditions, eliminating the need for separate calibration procedures for each attenuator stage while maintaining comprehensive power control capability.
3Device complexity
If conventional attenuator networks are used without feedback control, then device simplicity is maintained, but gain discontinuities occur and power level accuracy deteriorates
Solution Approach 1:
The patent introduces feedback control into the attenuator network by detecting the actual output power level with power detectors and comparing it against the desired power level. The resulting error signal is used to automatically adjust the attenuation stages, ensuring accurate power level control while maintaining relatively simple device architecture through the use of standard control circuitry.
Data Source
AI summary
A method to control adjustable power levels uses a network of attenuators that includes a fixed attenuation and a variable attenuation. The method adjusts the variable attenuation to approach the fixed attenuation, provides gain to an attenuated signal in an amount proximate to the fixed attenuation to generate a compensated signal, and compares power levels of a non-attenuated signal and the compensated signal to generate a first error signal. The method introduces the fixed attenuation and correspondingly reduces the variable attenuation to maintain a combined attenuation. The combined attenuation generates a modified compensated signal. The method measures a difference between the first power levels of the non-attenuated signal and the modified compensated signal to generate a second error signal, and generates a control signal as function of the first and second error signals to adjust the variable attenuation to reduce an attenuation mismatch introduced between the fixed and variable attenuations.