Temperature Compensated RF Peak Detector Using Replica Circuit

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Solution Overview

Problem

Conventional RF peak detectors experience gain variations with temperature changes, leading to uncertainty in sensitivity levels, and compensating for this often reduces available headroom.

Innovation Solution

A temperature-compensated RF peak detector design that includes a replica peak detector and a temperature-compensated threshold generator, using a proportional to absolute temperature (PTAT) current source and a resistor ladder network to adjust the detection threshold, ensuring consistent performance across a wide temperature range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional RF peak detectors are used without temperature compensation, then the device complexity is low, but the gain varies over temperature leading to uncertainty in sensitivity level

Engineering Contradiction:
Improvesensitivity levelVSAvoiddetector structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a replica peak detector that copies the main detector's structure and temperature characteristics. The replica detector generates a reference signal that tracks the main detector's gain variations, enabling temperature compensation without requiring complex external compensation circuits.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent implements a feedback mechanism where the reference signal from the replica detector is fed back to the threshold generator. This feedback loop automatically adjusts the detection threshold to compensate for temperature-induced gain variations, maintaining measurement precision across temperature ranges.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If current is increased in the peak detector to compensate for gain variations, then the gain stability improves, but the available headroom is reduced

Engineering Contradiction:
Improvegain stabilityVSAvoidavailable headroom
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of increasing current in the main detector, the patent copies the temperature compensation function to a separate replica detector. This approach maintains the main detector's operating point and available headroom while achieving gain stability through the replica's reference signal.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces a threshold generator as an intermediary component that uses the reference signal to adjust the detection threshold. This mediator handles the compensation function without requiring changes to the main detector's current operation, preserving available headroom.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If a replica peak detector and temperature-compensated threshold generator are added, then temperature dependence of gain is reduced, but the device complexity increases

Engineering Contradiction:
Improvetemperature compensationVSAvoiddetector components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a replica detector that copies only the essential temperature-dependent characteristics of the main detector, not the entire detector function. This selective copying achieves temperature compensation with minimal additional complexity.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent merges the temperature compensation function into the existing threshold generator architecture. By combining the reference signal processing with the threshold generation function, the patent avoids adding separate complex compensation circuits.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution reduces or eliminates temperature dependence of the gain, providing accurate RF peak detection in both transmitter and receiver applications, maintaining sensitivity and headroom across varying temperatures.

Implementation Method 1

using a proportional to absolute temperature (PTAT) current source and a resistor ladder network to adjust the detection threshold

Methodology Applied
Scientific EffectProportional to Absolute Temperature (PTAT) effect:

Data Source

PatentEP3020151B1Temperature compensated RF peak detector
Publication Date: 2017.08.23 QUALCOMM INC
  • EP3020151B1 patent drawingFigure 1
  • EP3020151B1 patent drawingFigure 2a~2b
  • EP3020151B1 patent drawingFigure 3~4

AI summary

A temperature compensated RF peak detector is disclosed. In an exemplary embodiment, an apparatus includes a first RF peak detector configured to generate a reference signal, a temperature compensated threshold generator configured to generate a temperature compensated detection threshold based on the reference signal, and a comparator configured to generate a peak detection output based on the temperature compensated detection threshold.