Power Amplifier Output Bypass Around a Directional Coupler
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Solution Overview
Problem
High-frequency amplifying circuits experience a reduction in output power due to power propagation through a directional coupler, leading to inefficiencies in signal transmission.
Innovation Solution
A power amplifying circuit configuration that includes a directional coupler with a connecting conductor bypassing the coupler, allowing amplified high-frequency signals to be output directly to a load without passing through the coupler, thereby reducing signal loss and maintaining output power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control is performed through a directional coupler, then output power control precision is improved, but output power is reduced due to power propagation through the coupler
Solution Approach 1:
The patent divides the signal path into two separate paths: one path through the directional coupler for feedback control and measurement, and another path bypassing the coupler for main signal transmission. This segmentation allows the feedback function to be isolated from the main power transmission path, eliminating the power loss caused by the coupler while preserving the feedback control capability.
Solution Approach 2:
The patent introduces a bypass path as an intermediary route that allows the main high-frequency signal to avoid the directional coupler entirely. This intermediary path serves as a mediator between the power amplifier output and the final output, enabling the signal to reach the load without experiencing the power propagation losses inherent in the coupler structure.
2Loss of substance
If power propagates through the subline of the directional coupler, then feedback control is enabled, but signal loss increases and output power decreases
Solution Approach 1:
The patent segments the signal flow into distinct functional paths: the subline of the directional coupler is dedicated solely to feedback signal extraction, while the main signal transmission is routed through a separate bypass path. This segmentation prevents the main signal from experiencing losses in the coupler structure while maintaining the feedback extraction function.
Solution Approach 2:
The patent extracts only the necessary feedback portion of the signal through the directional coupler's subline, while taking the main signal path out of the coupler structure entirely via the bypass path. This extraction approach allows feedback control to be maintained without subjecting the main signal to the power propagation losses that would occur if it passed through the coupler.
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
This configuration prevents output power reduction and improves power-added efficiency while allowing precise control of output power, enhancing signal transmission efficiency.
Implementation Method 1
a directional coupler including a main line connected at a first end thereof to an output terminal of the high-frequency amplifying circuit and connected at a second end thereof to a signal output terminal; the main line and a subline coupled to each other
Data Source
AI summary
A high-frequency module including a power amplifying circuit includes a high-frequency power amplifying element, a matching circuit, and a driving power-supply circuit. The high-frequency power amplifying element includes a high-frequency amplifying circuit and a directional coupler. A first end of a main line of the directional coupler is connected to an output terminal of a latter-stage amplifying circuit of the high-frequency amplifying circuit. A second end of the main line of the directional coupler is connected through an output matching circuit to a high-frequency signal output terminal of the high-frequency power amplifying element. The output terminal of the latter-stage amplifying circuit is also connected to a second driving power-supply voltage application terminal of the high-frequency power amplifying element. The second driving power-supply voltage application terminal is connected to the high-frequency signal output terminal by a connecting conductor.