RF Power Amplifier Output Bypass for Coupler Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency power amplifying circuits experience a reduction in output power due to the power propagating through a directional coupler, which affects the efficiency of signal transmission to loads like antennas.
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 through both the coupler and the bypass path, reducing signal loss and maintaining output power, along with matching circuits for impedance matching and direct-current voltage blocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control is performed through a directional coupler, then output power control is achieved, but output power reduction occurs due to power propagation through the coupler
Solution Approach 1:
The patent divides the output path into two separate segments: one path through the directional coupler for feedback control and measurement, and another bypass path that directly connects the power amplifier output to the load. This segmentation allows the main power signal to avoid the losses inherent in the coupler while still enabling precise feedback control through the coupler's sampling function.
Solution Approach 2:
The directional coupler acts as an intermediary element that samples a portion of the output signal for feedback control without forcing the entire power signal to pass through it. The bypass path provides a direct connection that mediates the power transmission, separating the measurement function from the power transmission function.
2Extent of automation
If all output signal passes through the directional coupler, then feedback control is enabled, but signal loss increases due to coupling effects
Solution Approach 1:
The signal path is segmented into a control path through the directional coupler and a main power path through the bypass connection. This allows automated feedback control to be implemented through the coupler while the majority of the signal power travels through the low-loss bypass path.
Solution Approach 2:
Instead of requiring the entire signal to pass through the directional coupler for feedback control, only a partial sample of the signal is directed through the coupler's coupling path, while the excess majority of the signal power flows through the bypass path with minimal loss.
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 effectively suppresses output power reduction and improves power-added efficiency while allowing precise control of output power, enhancing signal transmission efficiency to subsequent stages.
Implementation Method 1
a connecting conductor configured to bypass the directional coupler and connect the output terminal of the high-frequency amplifying circuit to the second end of the main line
Implementation Method 2
a directional coupler having 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
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A high-frequency module having 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.