Sequential Wideband Power Amplifier Layout With Reduced Line Loss
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Solution Overview
Problem
Existing power amplifiers face challenges in achieving high efficiency over a wide bandwidth while maintaining a reduced size and complexity, as extending the amplitude range with multiple sub-amplifier sections leads to increased electrical length and losses.
Innovation Solution
A power amplifier arrangement with sequentially activated transistors along an output transmission line, where each transistor turns on with increasing amplitude, and gate biases decrease along the line, allowing for an exponentially varying admittance, reducing transmission line length and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If multiple sub-amplifier sections are used to extend the amplitude range of high efficiency, then the efficiency performance is improved, but the total electrical length of the amplifier system increases leading to increased losses
Solution Approach 1:
The amplifier system is divided into multiple independent amplifier sections, each contributing a specific amplitude range of high-efficiency performance. These sections are connected in succession, with each section handling a portion of the overall amplitude range, thereby achieving extended high-efficiency operation without requiring a single excessively long transmission line
Solution Approach 2:
Instead of extending the amplitude range by increasing the electrical length in one dimension, the patent distributes multiple amplifier sections across different spatial locations along the transmission line. Each section is optimized for a specific amplitude range, and their combined effect achieves the desired extended performance without proportionally increasing total losses
2Loss of energy
If more amplifier sections are added to reduce efficiency droop between transition points, then the efficiency performance is improved, but the device complexity and transmission line length increase
Solution Approach 1:
Each amplifier section is designed with specific local characteristics optimized for its designated amplitude range. The sections have different impedance transformations and loading conditions tailored to their specific operating points, allowing each to maintain high efficiency in its local range while collectively covering a broad amplitude spectrum with minimal droop
Solution Approach 2:
The amplifier sections are designed to dynamically activate and deactivate based on the input signal amplitude. As the signal amplitude varies, different sections become dominant, with the transition between sections being smooth and coordinated. This dynamic operation allows the system to maintain high efficiency across the full amplitude range without requiring all sections to be simultaneously active, thereby reducing overall complexity
Data Source
AI summary
A power amplifier arrangement (100) for amplifying an input signal (Pin) to produce an output signal (Pout) is disclosed. The amplifier arrangement (100) comprise an input port (IN) for receiving the input signal; an output transmission line (110) having a first terminal (111) and a second terminal (112); an output port (OUT) coupled to the second terminal (112) of the output transmission line (110) for providing the output signal; and a plurality N of amplifying devices (121, 122, . . . 12N) distributed along the output transmission line (110). The power amplifier arrangement (100) is configured such that the plurality N of amplifying devices are active sequentially for amplifying the input signal with increasing amplitude of the input signal.