Doherty Amplifier Impedance Converter for Compact Matching
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Solution Overview
Problem
Current Doherty amplifiers face challenges in miniaturization due to low dielectric substrates and inefficient impedance matching, which affects their linearity and efficiency, particularly with high power transistors, and are costly due to metal packaging and complex tuning methods.
Innovation Solution
A Doherty amplifier design incorporating impedance converters with multiple lines of different lengths and satellite pads for impedance adjustment, connected via wire bonding, along with gallium nitride transistors and a modular structure for improved miniaturization and efficiency, reduces the need for screw fastening and allows for precise impedance matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional impedance conversion circuits are used with high power transistors, then impedance matching can be achieved, but the operation efficiency decreases and quality uniformity cannot be obtained
Solution Approach 1:
The patent implements dynamic impedance matching by making the impedance conversion circuit adjustable. The circuit can be tuned to different impedance values to match the specific characteristics of different high power transistors, thereby maintaining optimal operation efficiency while achieving precise impedance matching. This is accomplished through adjustable circuit elements that allow real-time optimization of the matching conditions.
Solution Approach 2:
The patent changes the impedance parameters of the conversion circuit to optimize both matching quality and efficiency. By adjusting circuit parameters such as component values and configuration, the system achieves uniform quality across different transistor variants while maintaining high operation efficiency, resolving the contradiction between precision and energy consumption.
2Power
If metal packages are used for carrier and peaking amplifiers, then high power Doherty amplifier can be fabricated, but the cost increases
Solution Approach 1:
The patent replaces expensive metal packages with cost-effective alternative packaging solutions. By using economical packaging materials and designs that can be manufactured more cheaply, the system maintains high power capability while significantly reducing manufacturing costs. The alternative packages are designed to meet the necessary electrical and thermal requirements without the premium cost of traditional metal packaging.
3Strength
If transistors are attached to metal package with screw fixing, then high power amplifier structure is achieved, but the area occupied increases hindering miniaturization
Solution Approach 1:
The patent merges the transistor mounting structure with the package itself, eliminating the need for separate screw fixing mechanisms. By integrating the mounting function directly into the package design, the system achieves structural stability while minimizing the area occupied. This integration allows the transistors to be securely attached without requiring additional space for screws and fastening hardware, thereby enabling miniaturization.
4Ease of manufacture
If FR-4 or Teflon substrates are used, then standard fabrication is achieved, but the size of Doherty amplifier cannot be reduced
Solution Approach 1:
The patent changes the substrate material parameters by selecting materials with higher dielectric constants than traditional FR-4 or Teflon. This parameter change allows for smaller physical dimensions of the amplifier components while maintaining the same electrical performance. The high dielectric constant enables miniaturization of the amplifier structure without sacrificing fabrication standards or electrical characteristics.
Data Source
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AI summary
The present invention relates to a Doherty amplifier, wherein in order to easily perform impedance matching, the Doherty amplifier according to the present invention comprises: an impedance converter, the length of which encompasses a plurality of other lines, and which is disposed between an output end of a carrier amplifier and an output end of a peaking amplifier; and a connector for connecting a line selected in the impedance converter to the output end of the carrier amplifier and to the output end of the peaking amplifier.