DSP-Based DC Offset Correction for Precise Phase Shifter Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phased array radar systems face challenges in maintaining precise phase differences between phase shifters due to variations in transmission distances and temperature changes, leading to reduced beam directivity and difficulty in eliminating phase errors without calibration.
Innovation Solution
A digital signal processor that corrects DC outputs at the output terminal of an analog circuit device using a digital register, D/A converter, polarity determining circuit, and updating function, eliminating the need for A/D converters and corrective phase shifters, allowing for precise phase adjustment between phase shifters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional phase shifters with transmission lines are used, then phase control is achieved, but transmission distance variations cause phase errors reducing beam directivity
Solution Approach 1:
The patent replaces the conventional mechanical transmission line-based phase shifter with a digital signal processing approach. Digital values are processed and converted to analog voltages to control phase shifters, eliminating the need for long transmission lines and their associated phase errors. This substitution of mechanical/electrical transmission with digital processing resolves the contradiction by maintaining phase precision without relying on physical transmission distance.
2Measurement precision
If A/D converters and corrective phase shifters are added to eliminate phase errors, then phase precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for A/D converters and corrective phase shifters from the conventional phase correction system. By using a digital signal processor that directly generates correction voltages through a D/A converter, the system removes unnecessary components while maintaining phase correction capability, thus reducing device complexity.
Solution Approach 2:
The digital signal processor performs multiple functions: it processes digital values, generates correction voltages, and controls phase shifters. This multi-functional approach consolidates what would traditionally require separate A/D converters and corrective phase shifters into a single integrated device, reducing overall system complexity while maintaining precision.
3Measurement precision
If calibration is performed to eliminate phase errors, then phase accuracy is improved, but operational time and complexity increase
Solution Approach 1:
The patent implements preliminary phase correction by pre-calculating and storing correction values in a digital register. The digital signal processor retrieves these pre-computed correction values and applies them in real-time without requiring ongoing calibration procedures. This preliminary action eliminates the need for time-consuming calibration while maintaining high phase accuracy.
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 phase correction between phase shifters, enhancing beam directivity without the need for A/D converters or corrective phase shifters, resulting in a more compact and efficient digital signal processor for phased array radar systems.
Implementation Method 1
a D/A converter for converting the digital value stored in the digital register into an analog voltage and applying the converted analog voltage to the output terminal as the DC output
Data Source
AI summary
The digital signal processor is for correcting a DC output at an output terminal of an internal circuit of an analog circuit device. The digital signal processor includes a digital register for storing a digital value, a D/A converter for converting the digital value stored in the digital register into an analog voltage and applying the converted analog voltage to the output terminal as the DC output, a polarity determining circuit which outputs a first signal when an analog DC voltage at a reference correction point different from the output terminal in the internal circuit is higher than a predetermined threshold value and otherwise outputs a second signal, and an updating function configured to monotonously increase or decrease the digital value stored in the digital register while a predetermined one of the first and second signals is outputted from the polarity determining circuit.