RF Power Amplifier Output Combiner for Efficiency and Size
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Solution Overview
Problem
Radio frequency power amplifiers face inefficiencies at low and intermediate input power levels while maintaining power efficiency in the saturation regime, and existing integration methods for output power combiners in RF integrated circuit packages lead to increased costs and non-uniform loading of amplifier stages, affecting performance.
Innovation Solution
A radio frequency power amplifier design with a main amplifier stage and a peak amplifier stage, integrated with an output power combiner that includes a first and second transition structure and electrical conductors to reduce electromagnetic coupling and provide uniform impedance loading, allowing for improved power efficiency and reduced package size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the output power combiner is integrated in one package using lumped capacitors and bond wires, then the power efficiency in saturation regime is maintained, but the package layout space increases and costs increase
Solution Approach 1:
The patent transitions from planar integration of the power combiner to a three-dimensional stacked configuration where the power combiner is integrated vertically above the amplifier stages. This dimensional change allows compact integration without increasing lateral package footprint, resolving the contradiction between maintaining power efficiency and reducing package area.
2Use of energy by moving object
If the output power combiner is integrated in one package, then the power efficiency in saturation regime is maintained, but the manufacturing costs increase
Solution Approach 1:
The patent merges the power combiner function with the existing package structure by integrating it vertically above the amplifier stages using shared substrates and interconnect structures. This consolidation approach maintains the performance benefits of integration while reducing overall manufacturing complexity and costs compared to separate discrete components.
3Use of energy by moving object
If large active dies with gate periphery larger than 60 mm are used, then the power efficiency in saturation regime is maintained, but parasitic distributed inductances and capacitances increase
Solution Approach 1:
The patent reduces parasitic effects by transitioning from lateral signal paths to vertical interconnects through the stacked architecture. This dimensional change shortens current paths and minimizes the area occupied by interconnect structures, thereby reducing parasitic distributed inductances and capacitances while maintaining large active die sizes for saturation performance.
4Use of energy by moving object
If a wide output lead is used, then the power efficiency in saturation regime is maintained, but parasitic distributed inductances and capacitances increase
Solution Approach 1:
The patent replaces wide lateral output leads with vertical interconnect structures that extend perpendicular to the substrate plane. This dimensional transition maintains the current-carrying capacity needed for saturation performance while significantly reducing the lateral footprint and associated parasitic distributed inductances and capacitances.
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 solution enhances power efficiency across a larger linear domain, reduces package size, and improves the uniformity of load impedance, leading to better performance and cost-effectiveness in RF power amplifiers.
Implementation Method 1
an output power combiner for combining the main output signal and the peak output signal into the output signal, comprising a first combiner terminal electrically coupled to the main output terminal for receiving the main output signal from the main output terminal and a second combiner terminal electrically coupled to the peak output terminal for receiving the peak output signal from the peak output terminal. The power combiner further comprises a first transition structure extending from the first combiner terminal in a first direction to a first end, a second transition structure extending from the second combiner terminal in the first direction to a second end, a first electrical conductor for providing a phase shift between the main output signal and the peak output signal, the first electrical conductor being arranged between the first end and the second end
Data Source
AI summary
A radio frequency power amplifier comprises an input and output terminals, a main and peak amplifier stages, and an output power combiner for combining a main output signal and a peak output signal into an output signal. The output power combiner comprises a first combiner terminal electrically coupled to a main output terminal, a second combiner terminal electrically coupled to a peak output terminal, a first transition structure extending from the first combiner terminal in a first direction to a first end, a second transition structure extending from the second combiner terminal in the first direction to a second end, a first electrical conductor arranged between the first and the second ends, and a second electrical conductor arranged between the second combiner terminal and the output terminal. The first electrical conductor extends in a second direction perpendicular to the first direction. The second electrical conductor extends in the first direction.