Quadrature Phase Signal Correction Using Programmable Delay Elements
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Solution Overview
Problem
Quadrature phase generators in communication devices often produce signal pairs with relative phase errors due to different propagation delays, leading to undesirable sideband images and errors in data detection, which complicates circuit design and increases costs.
Innovation Solution
A method and apparatus using programmable delay elements and a control circuit to adjust the delay and duty cycle of quadrature phase signal pairs, generating corrected in-phase and quadrature phase signals with a 90-degree phase difference, eliminating the need for separate phase adjustment signals and reducing circuit complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional quadrature phase generators are used, then signal generation is simple, but relative phase errors occur due to different propagation delays
Solution Approach 1:
The patent implements a feedback mechanism where the quadrature phase signals are monitored and the propagation delay difference is detected. Based on this feedback, the system dynamically adjusts the delay of one signal path to compensate for the delay mismatch, thereby maintaining accurate 90-degree phase relationship without requiring complex pre-designed circuitry
Solution Approach 2:
The patent changes the delay parameter of one signal path dynamically to compensate for propagation delay differences. By adjusting the delay value based on detected phase errors, the system maintains precise phase accuracy without fixing the circuit topology, thus avoiding increased device complexity
2Manufacturing precision
If separate phase adjustment signals are used to correct phase errors, then phase accuracy improves, but circuit complexity and power consumption increase
Solution Approach 1:
The patent merges the phase adjustment function with the existing quadrature phase generator circuitry. Instead of using separate phase adjustment signals and dedicated adjustment circuits, the system integrates delay adjustment directly into the signal generation path, eliminating redundant components and reducing power consumption while maintaining phase accuracy
3Manufacturing precision
If separate phase adjustment signals are used to correct phase errors, then phase accuracy improves, but circuit complexity increases
Solution Approach 1:
The patent designs the delay adjustment mechanism to serve multiple functions: it not only corrects phase errors but also works across different operating conditions and signal frequencies. This universal approach eliminates the need for separate adjustment circuits for different scenarios, thereby reducing overall circuit complexity while maintaining high phase accuracy
4Ease of manufacture
If propagation delays are not compensated, then circuit design is simple, but signal transmission and reception accuracy deteriorates
Solution Approach 1:
The patent implements preliminary delay compensation by detecting propagation delay differences early in the signal generation process and adjusting the delay before the signals are used for modulation or demodulation. This preliminary action ensures phase accuracy is maintained throughout subsequent signal processing operations without requiring complex redesign of the entire system
Data Source
AI summary
A method and an apparatus (300) for generating corrected quadrature phase signal pairs in a communication device are provided. The apparatus (300) includes a quadrature phase generator (310), programmable delay elements (320, 330) and a control circuit (360). The programmable delay elements (320, 330) receive a quadrature phase signal pair (signals I 312 and Q 314) from the quadrature phase generator (310). The control circuit (360) generates a control signal (362) based on outputs (325, 335) of the programmable delay elements (320, 330). The control signal (362) configures the programmable delay elements (320, 330). The programmable delay elements (320, 330) are configured to adjust delay between the signals I (312) and Q (314). The programmable delay elements (320, 330) are also used to adjust duty cycle for the quadrature phase signal pair to provide the corrected quadrature phase signal pair.