Differential Buffer Phase Correction Using Feedback Capacitors
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Solution Overview
Problem
Wireless communication systems face challenges in maintaining phase balance in the differential buffer of quadrature generators, leading to phase mismatches that affect signal quality and efficiency.
Innovation Solution
The implementation of a phase correction apparatus using a differential buffer with a first and second inverter connected in series, along with feedback capacitors to correct phase mismatches between the inverters, ensuring improved phase balance and reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional differential buffer is used in the quadrature generator, then the circuit structure is simple, but phase imbalance occurs between the differential signals
Solution Approach 1:
The patent introduces feedback capacitors that connect the output of each inverter back to its own input and cross-connect to the other inverter's input. This feedback mechanism compensates for phase imbalances by continuously adjusting the phase of the differential signals, achieving approximately 50% reduction in phase imbalance while maintaining a relatively simple circuit structure.
Solution Approach 2:
The patent modifies the conventional differential buffer by adding capacitive elements that change the electrical parameters of the circuit. The feedback capacitors alter the phase characteristics of the differential signals, transforming the phase balance parameter from imbalanced to balanced state without fundamentally changing the inverter-based circuit topology.
2Manufacturing precision
If phase correction components are added to the differential buffer, then phase balance is improved, but power consumption increases
Solution Approach 1:
The feedback capacitors passively correct phase imbalances by utilizing the existing signal energy in the differential buffer. Rather than requiring active power-consuming correction circuits, the capacitive feedback network redistributes the existing energy to achieve phase balance, resulting in only 10% additional power consumption while achieving 50% phase imbalance reduction.
3Reliability
If feedback capacitors are added to correct phase imbalance, then signal quality is improved, but device complexity increases
Solution Approach 1:
The patent achieves signal quality improvement by modifying the electrical parameters of the existing circuit through capacitive feedback, rather than adding complex active correction circuits. The feedback capacitors simply change the phase response characteristics of the differential buffer, improving signal quality while adding minimal component complexity.
Data Source
AI summary
A method for differential buffer phase correction comprises generating a pair of differential signals from a local oscillator, applying one of the signals to a first inverter and the other signal to a second inverter of a buffer through a differential pair of lines, applying a first positive feedback signal to the first inverter through a first feedback capacitor, wherein the first positive feedback signal is generated from an output of the second inverter and applying a second positive feedback signal to the second inverter through a second feedback capacitor, wherein the second positive feedback signal is generated from an output of the first inverter.