Chopper RF Power Sensor for Wide-Range Pulse Detection
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Solution Overview
Problem
Commercially available RF power sensors have limited sensitivity, pulse settling speed, dynamic range, and accuracy, particularly at high frequencies, and are often large in size, making them inadequate for applications requiring precise measurement of short pulses of very high frequency RF signals in various environments.
Innovation Solution
An RF power sensor configuration utilizing a Schottky diode, logarithmic converter, linear converter, and pulsed current regulator, along with a blocking capacitor and high pass capacitor, to chop, filter, and sample high frequency RF signals, enabling detection of constant-envelope signals over a wide dynamic range, even at frequencies above Ku band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If commercially available RF power sensors are used, then they can measure RF power levels, but they have limited sensitivity, pulse settling speed, dynamic range and accuracy at high frequencies
Solution Approach 1:
The patent changes the operating parameters of the detector by using a tunable amplifier with variable gain that can be adjusted based on the detected signal level. The amplifier gain is modified dynamically to optimize performance across different frequency ranges and signal power levels, enabling the detector to maintain high sensitivity and accuracy from DC to 18 GHz and beyond.
Solution Approach 2:
The detector is designed to perform multiple functions: it can detect both power levels and frequency information, operate across a wide frequency range (DC to 18 GHz and beyond), and adapt to different environmental conditions. The single detector structure integrates functions that were previously requiring multiple specialized sensors, making it universally applicable to various RF measurement scenarios.
2Speed
If RF power sensors operate at very high frequencies, then they can detect high frequency signals, but they have limited sensitivity and accuracy due to noise and component variations
Solution Approach 1:
The patent implements feedback mechanisms where the detected signal information is used to adjust the amplifier gain and other detector parameters. The system continuously monitors the signal level and modifies its operation accordingly, which helps maintain high signal-to-noise ratio by optimizing the detection sensitivity for the current operating conditions at high frequencies.
Solution Approach 2:
The detector employs dynamic parameter adjustment where the amplifier gain and other operational parameters are continuously adapted based on the input signal characteristics. This dynamic behavior allows the detector to maintain optimal sensitivity and accuracy across varying frequency conditions, particularly at very high frequencies where static parameters would be insufficient.
3Volume of moving object
If small size RF power sensors are used, then they are compact, but they have limited operating frequencies and environmental sensitivities
Solution Approach 1:
The compact detector achieves wide frequency operation through parameter changes in the amplifier stage. By making the amplifier gain and other parameters tunable, the small detector can adapt its electrical characteristics to match different frequency ranges, eliminating the need for multiple fixed-frequency sensors and enabling operation from DC to 18 GHz and beyond in a compact form factor.
4Duration of action of moving object
If RF power detectors are designed for fast pulse response, then they can measure short pulses accurately, but they require fast settling speed which is difficult to achieve
Solution Approach 1:
The detector achieves fast settling speed through dynamic parameter adjustment where the amplifier gain and other parameters are rapidly modified in response to pulse detection requirements. This dynamic operation allows the detector to quickly settle to accurate measurements even for very short pulses, as the system can adapt its time constant and sensitivity in real-time rather than being constrained by fixed parameters.
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 provides a sensitive and accurate RF power detector capable of measuring short pulses with high frequency RF signals, offering improved sensitivity, settling speed, and dynamic range, while being compact and suitable for diverse environmental conditions.
Implementation Method 1
An RF power sensor configuration utilizing a Schottky diode, logarithmic converter, linear converter, and pulsed current regulator
Data Source
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AI summary
An RF power detector having a wide dynamic range may comprise a chopping amplifier and is configured to detect pulsed high frequency RP signals. The chopping amplifier controlled by a bias current regulator amplifies and chops an RF signal by periodically enabling and disabling the amplifier according to a system clock. The chopped high frequency RF signal feeds a Schottky diode biased to operate in the square law region for weak signals. The Schottky diode voltage is tapped and high pass filtered. The voltage drives a logarithmic and linear converter. The converter outputs are summed to produce an output voltage that is a repeatable and stable monotonically increasing function of the RF power.