Inline RF Phase Shift Measurement Using an Oscillator Loop
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Solution Overview
Problem
Existing systems fail to accurately measure and compensate for phase shifts introduced by inline devices, which are crucial for maintaining precise phase relations in electronic devices like beamforming devices due to factors such as device installation and temperature changes.
Innovation Solution
A system and method using a variable gain amplifier and adjustable phase shifter within an oscillator circuit to determine and compensate for phase shifts by locating block phase shifts and adjusting operations to meet Barkhausen phase conditions, allowing for efficient phase shift measurement and compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an inline device is installed in the signal path, then the phase relation can be adjusted, but an extra phase shift is introduced that degrades measurement precision
Solution Approach 1:
The patent introduces a test signal path with a test oscillator and test ADC as intermediary components to measure the phase shift caused by the inline device. This intermediary measurement system allows the inline device to remain in the main signal path for phase adjustment while its phase shift effect is separately quantified and compensated through calibration data stored in a lookup table.
2Adaptability or versatility
If devices are repeatedly installed or temperature changes occur, then operational flexibility is improved, but phase shift variations increase that harm reliability
Solution Approach 1:
The patent performs preliminary calibration by measuring the phase shift of the inline device under various temperatures and installation conditions before actual operation. The measured phase shift values are stored in a lookup table, enabling the system to pre-compensate for these variations during operation without requiring real-time adjustments, thus maintaining reliability despite installation flexibility.
3Measurement precision
If phase compensation is implemented, then phase relation accuracy is improved, but system complexity increases
Solution Approach 1:
The patent creates a simplified copy of the main signal path by using a test oscillator that generates a test signal through the inline device and a test ADC to capture the output. This copy system allows phase shift measurement without requiring complex modifications to the main signal path, reducing overall system complexity while achieving accurate phase compensation.
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
Enables precise measurement and compensation of phase shifts introduced by inline devices, ensuring accurate operation of electronic systems by adjusting gain and phase to meet Barkhausen conditions, thereby maintaining desired phase relations.
Implementation Method 1
locating the block phase shift by varying the phase of the variable feedback block until the loop meets a Barkhausen phase condition
Data Source
AI summary
A testing device includes an oscillator circuit with an inline device. The oscillator circuit includes a loop having a variable gain amplifier and a variable feedback block. The inline device is installed between the variable gain amplifier and the variable feedback block. An output of the variable feedback block is input to the variable gain amplifier. A processor varies a phase of the variable feedback block to locate a block phase shift of the variable feedback block at which the oscillator circuit generates an output signal, determines a device phase shift of the inline device from the block phase shift, and adjusts an operation of a driven circuit operating off of the output of the oscillator circuit using the device phase shift of the inline device.