Logarithmic Power Detector With DC Offset Noise Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency logarithmic power detectors face significant noise issues due to large input signal bandwidth, limiting detection dynamic range and distorting log-linear characteristics, especially at low-end input signal powers.
Innovation Solution
A log power detector design incorporating a gain or attenuation circuit with a sequence of elements and a detector circuit, where the last detector receives a unique DC offset signal different from others, and optionally utilizes a triple-tail cell (TTC) circuit with adjustable DC offset for noise compensation, particularly effective at high frequencies and low-power inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-frequency log detector is used to measure RF signal power, then frequency range is extended, but noise increases significantly
Solution Approach 1:
The detector is divided into multiple detector elements, each handling a specific portion of the dynamic range. This segmentation allows each element to operate optimally within its range while reducing the impact of noise across the entire system.
Solution Approach 2:
The patent applies different DC offset values to different detector elements to compensate for noise. By changing the operating parameters (DC offset) of each detector element, the system maintains accurate log-linear characteristics across the full dynamic range while compensating for noise effects.
2Adaptability or versatility
If large bandwidth is used to detect high-frequency signals, then frequency measurement capability is improved, but noise-related errors increase
Solution Approach 1:
The detector circuit is segmented into multiple detector elements, each with specific bandwidth characteristics. This allows the system to utilize large bandwidth for high-frequency detection while each element processes signals within optimized bandwidth limits, reducing noise-related errors.
Solution Approach 2:
Different DC offset parameters are applied to different detector elements to compensate for noise introduced by large bandwidth. This parameter adjustment maintains measurement precision across the full bandwidth range.
3Device complexity
If conventional log detector design is used, then simple structure is maintained, but log-linear characteristics are distorted at low power
Solution Approach 1:
The detector is segmented into multiple elements that collectively cover the full dynamic range. This segmentation maintains relatively simple individual element structures while achieving accurate log-linear characteristics across the entire power range through their combination.
Solution Approach 2:
Different DC offset values are applied to different detector elements to correct log-linear characteristic distortion at low power levels. This parameter adjustment maintains measurement precision without significantly increasing overall structural complexity.
4Device complexity
If single detector element is used, then device complexity is reduced, but detection dynamic range is limited
Solution Approach 1:
The detector is divided into multiple detector elements, each optimized for specific portions of the dynamic range. This segmentation extends the overall detection dynamic range while keeping each individual element relatively simple.
Solution Approach 2:
Multiple detector elements are merged into a unified detector circuit with combined output. This merging allows the system to achieve extended dynamic range while presenting a relatively simple interface to the rest of the system.
Data Source
AI summary
An example log power detector includes a gain or attenuation circuit and a detector circuit. The gain or attenuation circuit includes a plurality of gain or attenuation elements arranged in a sequence, each gain or attenuation element configured to generate an output signal that is an amplified or attenuated version of an input signal provided thereto. The detector circuit includes a plurality of detectors, each detector configured to receive the output signal from a different one of the gain or attenuation elements and to generate a signal indicative of a power of the received output signal. At least the last detector is configured to receive a DC offset signal that is different from a DC offset signal received by at least one other detector. Such a log detector may provide effective noise compensation to reduce errors caused by input noise, especially for low-power and/or high-frequency input signals.