LTE Front-End Radio Architecture With Single PA and Multiplexing Transformers
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Solution Overview
Problem
Existing front end radio architectures (FERAs) for LTE-Advanced user equipment require multiple power amplifiers, making them costly and inefficient, particularly for multi-carrier operation in intra-band and inter-band transmission and reception modes.
Innovation Solution
A single power amplifier topology combined with multiplexing transformer structures that process in-phase and out-of-phase carrier signals, along with split-band duplexers, to enable cost-effective and efficient operation in LTE-Advanced modes, reducing complexity and nonlinearity inter-modulation products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple power amplifiers are used for multi-carrier operation, then transmission capability is improved, but device cost and complexity increase
Solution Approach 1:
The patent combines multiple power amplifier functions into a single power amplifier by using a dual-output PA die with two half-amplifier cells that can be independently controlled. The multiplexing transformer allows one PA to generate multiple carrier signals by switching between different half-amplifier cells, thereby reducing the total number of PAs required while maintaining multi-carrier operation capability.
Solution Approach 2:
The single power amplifier is designed to perform multiple functions by incorporating a multiplexing transformer that can route signals to different outputs based on operational mode. The PA can operate in intra-band contiguous mode, intra-band non-contiguous mode, and inter-band mode, making it a universal solution for various LTE-Advanced multi-carrier scenarios without requiring separate amplifiers for each mode.
2Adaptability or versatility
If multiple power amplifiers are used for multi-carrier operation, then transmission capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple PA functions into a single integrated PA die, reducing the total component count and assembly complexity. By using one PA with multiple outputs instead of multiple separate PAs, manufacturing costs are reduced due to fewer components to source, test, and assemble, while still achieving multi-carrier transmission capability.
3Device complexity
If a single power amplifier is used, then cost and complexity are reduced, but inter-modulation distortion increases
Solution Approach 1:
The PA die is segmented into two independent half-amplifier cells, each capable of amplifying a separate carrier signal. The multiplexing transformer selectively connects these half-cells to different outputs based on the operating mode, allowing the system to maintain linearity and reduce inter-modulation distortion by properly isolating and amplifying each carrier through dedicated amplifier paths.
Solution Approach 2:
The multiplexing transformer acts as an intermediary device that manages the interaction between the two half-amplifier cells and the antenna. It ensures proper signal routing and isolation, preventing harmful inter-modulation products from mixing while still allowing efficient multi-carrier transmission through the single PA structure.
4Device complexity
If a single power amplifier is used, then cost and complexity are reduced, but power consumption increases
Solution Approach 1:
The system dynamically switches between different half-amplifier cells based on the required operating mode (intra-band or inter-band). This dynamic switching allows the PA to optimize power consumption by activating only the necessary amplifier paths for each specific transmission scenario, rather than continuously powering all amplifier components at full capacity.
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 solution allows for efficient dual-carrier intra-band and inter-band operation while minimizing de-sense and inter-modulation distortion, reducing power consumption and complexity, thus enhancing the operational efficiency and cost-effectiveness of LTE-Advanced user equipment.
Implementation Method 1
The first and second PA transformers are each differential transformers having a first winding, a second winding, and a third winding. The first winding of the first transformer is coupled to the output amplifier stage of the first half amplifier cell, and the first winding of the second transformer is coupled to the output amplifier stage of the second half amplifier cell.
Data Source
AI summary
A front end radio architecture (FERA) is disclosed that includes a power amplifier (PA). The PA includes first and second input terminals and first and second output terminals and a PA die having first and second half amplifier cells, each of which includes an output amplifier stage. The first and second half amplifier cells are coupled to the first and second input terminals. First and second PA transformers each include first, second, and third windings. The first windings are coupled to the output amplifier stages. The second winding of the first PA transformer is coupled to the first output terminal of the PA and also coupled in series with the second winding of the second PA transformer. The third winding of the first PA transformer is coupled in series with the third winding of the second PA transformer, with one end of the second PA transformer being coupled to the second output terminal of the PA.