Quadrature Amplifier RF Coupling for Directivity Without Bulky Couplers
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Solution Overview
Problem
Existing RF amplifying systems based on quadrature combined amplifiers use bulky directional couplers, increasing the size and cost of the system.
Innovation Solution
An RF coupling circuit comprising a phase shifting component and a coupling network that provides a predetermined phase shift to an RF signal from a quadrature combined amplifier, allowing for directivity in the RF coupled output without the need for an additional directional coupler, thereby reducing system size and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a directional coupler is used to obtain RF coupled output with directivity, then directivity is achieved, but the system size and cost increase due to the bulky directional coupler
Solution Approach 1:
The patent extracts the directional coupling function from a separate bulky directional coupler component and integrates it into the quadrature combined amplifier structure itself. By using the existing 90-degree phase difference between the two output signals of the quadrature amplifier and combining them through a simple resistive network, the directional coupling function is achieved without requiring an additional directional coupler component, thereby reducing system size while maintaining directivity.
Solution Approach 2:
The patent merges the RF output signals from the two amplifiers directly through a resistive coupling network rather than using a separate directional coupler. The 90-degree phase shifted signals are combined in a way that produces both the main RF output and the coupled output with directivity, consolidating multiple functions into a single integrated structure.
2Measurement precision
If a directional coupler is used to obtain RF coupled output with directivity, then directivity is achieved, but the system cost increases due to the bulky directional coupler
Solution Approach 1:
The patent removes the need for a separate directional coupler component and extracts the directional coupling functionality into the amplifier's output stage. This eliminates the cost of purchasing and installing a bulky directional coupler while maintaining the required directivity performance through a simpler, more cost-effective resistive coupling network.
Solution Approach 2:
The patent replaces the expensive, bulky directional coupler with a simple resistive coupling network using basic resistors and transmission lines. These inexpensive components achieve the same directional coupling function at a fraction of the cost, making the system more economically viable.
3Measurement precision
If additional components are added to achieve directivity in RF output, then directivity is improved, but the system complexity increases
Solution Approach 1:
The patent makes the quadrature combined amplifier output stage multi-functional by designing it to simultaneously provide both the main RF power output and the directional coupled output. The same 90-degree phase shifted signals that are combined for the main output are also utilized to generate the coupled output with directivity, eliminating the need for separate dedicated components and reducing overall system complexity.
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
The RF coupling circuit achieves directivity in the RF output with reduced insertion loss and overall system cost, maintaining performance across varying load impedances.
Implementation Method 1
The phase shifting component provides a predetermined phase shift to a first RF signal at the first output terminal of the quadrature combined amplifier
Data Source
AI summary
A radio frequency (RF) coupling circuit for coupling an RF output of a quadrature combined amplifier. According to an embodiment, the RF coupling circuit includes a phase shifting component and a coupling network. The phase shifting component provides a predetermined phase shift to an RF signal at a first output terminal of the quadrature combined amplifier. The coupling network combines the phase shifted first output signal with an RF signal at a second output terminal of the quadrature combined amplifier.