Lumped LC Outphasing Power Combiner for Low-Frequency Efficiency
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Solution Overview
Problem
Conventional outphasing power combiners are inefficient at power back-off and result in spectral spreading due to large chip area consumption and lossy components like transformers, and quarter wave transmission lines are unsuitable for lower frequencies, leading to degraded system linearity and efficiency.
Innovation Solution
A lumped element power combiner using capacitors and inductors with compensation impedances to minimize impedance effects, allowing for efficient signal combination and phase shifting, optimized for on-chip integration at lower frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional outphasing power combiners are used, then signal combination is achieved, but chip area consumption increases and efficiency degrades at power back-off
Solution Approach 1:
The patent transforms the conventional quarter-wave transmission line structures into lumped element LC circuits by changing the physical implementation parameters. This allows the same electrical function to be achieved with significantly reduced physical dimensions while maintaining the impedance transformation and signal combination characteristics needed for efficient operation at power back-off conditions.
Solution Approach 2:
The patent creates an equivalent electrical model using lumped capacitors and inductors that replicates the functionality of distributed quarter-wave transmission lines. This equivalent circuit copying achieves the same impedance matching and signal combining effects without requiring the large physical dimensions of the original transmission line structure.
2Reliability
If quarter wave transmission lines are used for frequency conversion, then signal combination is achieved, but they are unsuitable for lower frequencies leading to degraded system linearity
Solution Approach 1:
The patent changes the operating parameters of the frequency conversion stage by replacing quarter-wave transmission lines with lumped LC elements that can be optimized for lower frequency operation. This parameter change enables reliable linear operation at frequencies where quarter-wave lines would be impractically large, thus improving system linearity while expanding frequency adaptability.
3Loss of energy
If lossy components like transformers are used, then power combination is achieved, but efficiency decreases due to component losses
Solution Approach 1:
The patent extracts and removes the lossy transformer component from the power combination circuit. By taking out the problematic transformer element and replacing it with ideal or low-loss lumped LC components, the design eliminates the primary source of power loss while maintaining the power combination function through reactive impedance transformation.
Solution Approach 2:
The patent replaces expensive, lossy transformer components with cheaper, lower-loss lumped element capacitors and inductors. These alternative components provide the necessary impedance transformation with significantly reduced power loss, making the overall system more efficient while being easier to manufacture and integrate.
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 achieves improved efficiency and reduced area consumption, enabling efficient power combination and maintaining high performance even at lower frequencies, with adjustable compensation for different outphasing angles and signal configurations.
Implementation Method 1
a first input terminal, a first inductor, and a first capacitor, wherein the first input terminal is connected to ground via the first inductor and the first input terminal is connected to the output terminal via the first capacitor
Implementation Method 2
a first input terminal, a first inductor, and a first capacitor, wherein the first input terminal is connected to ground via the first inductor and the first input terminal is connected to the output terminal via the first capacitor
Implementation Method 3
a second input terminal, a second capacitor, and a second inductor, wherein the second input terminal is connected to ground via the second capacitor and the second input terminal is connected to the output terminal via the second inductor
Implementation Method 4
a second input terminal, a second capacitor, and a second inductor, wherein the second input terminal is connected to ground via the second capacitor and the second input terminal is connected to the output terminal via the second inductor
Data Source
AI summary
A power combiner for an outphasing amplifier system comprises an output terminal, a first input terminal, a first inductor, and a first capacitor, wherein the first input terminal is connected to ground via the first inductor and the first input terminal is connected to the output terminal via the first capacitor. The power combiner further comprises a second input terminal, a second capacitor, and a second inductor, wherein the second input terminal is connected to ground via the second capacitor and the second input terminal is connected to the output terminal via the second inductor. The first capacitor can have a same capacitance as the second capacitor and the first inductor has a same inductance as the second inductor.