RF Complex Reflection Coefficient Reader Using Directional Coupler
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Solution Overview
Problem
Conventional methods for measuring the complex reflection coefficient in wireless devices are inefficient, costly, and inaccurate, particularly in environments where antenna impedance changes due to environmental factors, leading to signal mismatch and energy wastage, and are cumbersome due to the need for additional components like frequency downconverters.
Innovation Solution
A system that determines the complex reflection coefficient by using a directional coupler and power detectors to isolate and measure the magnitude and phase of the reflection coefficient, eliminating the need for frequency downconverters and providing continuous impedance matching information for antenna tuners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional frequency downconversion schemes are used to measure reflection coefficient, then the measurement capability is achieved, but chip area and power consumption increase due to additional frequency downconverters, local oscillator buffers, and baseband circuitry
Solution Approach 1:
The patent extracts only the necessary measurement function from the conventional frequency downconversion scheme. Instead of using full frequency downconverters with local oscillators and baseband circuitry, the invention uses a simplified approach with a power detector and phase detector that directly measure the reflection coefficient magnitude and phase without frequency conversion, eliminating unnecessary components and reducing chip area.
Solution Approach 2:
The patent replaces the complex frequency downconversion mechanism (involving mixers, local oscillators, and baseband processing) with a direct detection mechanism using power detectors and phase detectors. This substitution eliminates the need for frequency conversion hardware while maintaining measurement capability, thereby reducing device complexity and power consumption.
2Measurement precision
If conventional frequency downconversion schemes are used to measure reflection coefficient, then the measurement capability is achieved, but power consumption increases due to additional frequency downconverters, local oscillator buffers, and baseband circuitry
Solution Approach 1:
The patent extracts only the essential measurement function from the conventional scheme, using power detectors and phase detectors that consume significantly less power than frequency downconverters, local oscillator buffers, and baseband circuitry. This extraction approach maintains measurement precision while dramatically reducing power consumption.
Solution Approach 2:
The patent substitutes the high-power frequency downconversion system with low-power direct detection circuitry. The power detector and phase detector require minimal power compared to the mixers, local oscillators, and baseband processing equipment, thereby solving the power consumption problem while preserving measurement capability.
3Adaptability or versatility
If conventional approaches are used in FDD schemes, then the system operates in frequency division duplex mode, but measurement accuracy of reflection coefficient decreases due to simultaneous existence of receive and transmit signals
Solution Approach 1:
The patent segments the signal measurement process by using a directional coupler to separate the transmitted signal from the reflected signal. This segmentation allows accurate measurement of the reflection coefficient even in the presence of simultaneous transmit and receive signals in FDD mode, as the directional coupler isolates the reflected signal path from the transmit signal.
Solution Approach 2:
The patent introduces a directional coupler as an intermediary component that mediates between the transmit and receive paths. This intermediary device enables accurate reflection coefficient measurement by coupling only the reflected signal to the measurement circuitry while isolating it from the strong transmit signal, thereby maintaining measurement accuracy in FDD operation.
4Ease of operation
If only magnitude of reflection coefficient is measured, then measurement is simpler, but information about complex antenna impedance is not provided
Solution Approach 1:
The patent merges magnitude measurement and phase measurement into a single integrated system. By combining the outputs of the power detector (magnitude) and phase detector (phase), the system provides complete complex reflection coefficient information, which enables full complex antenna impedance determination while maintaining operational simplicity through unified circuit architecture.
Solution Approach 2:
The patent creates a universal measurement system that simultaneously provides both magnitude and phase information of the reflection coefficient. This multi-functional system can determine complete complex antenna impedance characteristics, making it applicable to various impedance matching scenarios while maintaining ease of operation through a single integrated measurement apparatus.
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
Improves wireless device performance by reducing signal loss, enhancing uplink and downlink capacity, and extending battery life by accurately matching antenna impedance, thereby minimizing energy wastage and preventing circuit damage from standing waves.
Implementation Method 1
a directional coupler and power detectors to isolate and measure the magnitude and phase of the reflection coefficient
Implementation Method 2
a directional coupler and power detectors to isolate and measure the magnitude and phase of the reflection coefficient
Data Source
AI summary
A radio frequency (RF) circuitry includes a device that taps a transmission line and picks up some of electromagnetic signals traveling in both directions. The RF circuitry includes a first detector, a second detector, a third detector, and a processor. The first detector measures a power of a first portion of the tapped electromagnetic signal travelling in one direction. The second detector measures a power of a first portion of the tapped electromagnetic signal travelling in the other direction. The third detector measures a power of a combined signal which includes a second portion of the tapped electromagnetic signal travelling in the one direction and a second portion of the tapped electromagnetic signal travelling in the other direction. The processor determines, based on outputs from the detectors, a relative magnitude and a relative phase of the electromagnetic signals.