Uplink Carrier Aggregation RF Circuit IMD3 Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems like LTE-Advanced, supporting simultaneous transmitters poses challenges due to intermodulation distortion (IMD) from high power signals, particularly third-order IMD3, which affects receive signals by creating products that overlap with fundamental frequencies, impacting performance.
Innovation Solution
The uplink carrier aggregation architecture separates TX and RX paths using dual antenna ports and RF circuits, with switchable paths and filters to route signals between them, reducing IMD3 by isolating offending TX signals from victim RX signals, thereby improving signal processing and reducing distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high power TX signals are routed and processed at the front-end, then simultaneous transmitter operation is enabled, but intermodulation distortion is generated affecting RX signals
Solution Approach 1:
The patent divides the RF front-end into separate first and second RF circuits, each handling specific TX and RX signals independently. The first RF circuit processes first TX and RX signals while the second RF circuit processes second TX and RX signals, preventing intermodulation between them by segmenting the signal paths.
Solution Approach 2:
The patent extracts and separates the problematic intermodulation products from the desired RX signals by routing them through different RF circuits. The second RX signal is routed through the first RF circuit where it is separated from intermodulation products generated in the second RF circuit.
2Object-generated harmful factors
If separate RF circuits are used for different signal paths, then intermodulation distortion is reduced, but device complexity increases
Solution Approach 1:
The first RF circuit serves multiple functions: it processes the first TX and RX signals and also routes the second RX signal while filtering out intermodulation products. This multi-functionality reduces the need for completely separate dedicated circuits for each signal type, thereby managing complexity.
Solution Approach 2:
The patent combines the routing of second RX signal with the existing first RF circuit infrastructure, merging multiple signal handling functions into a unified circuit design that reduces overall system complexity compared to fully separate dedicated paths.
Data Source
AI summary
Uplink carrier aggregation architecture. In some embodiments, an uplink (UL) carrier aggregation (CA) architecture may include a first antenna port and a second antenna port. The UL CA architecture may also include a first radio-frequency (RF) circuit configured to route a first transmit (TX) signal and a first receive (RX) signal to and from the first antenna port, respectively, the first RF circuit further configured to route a second RX signal from the first antenna port. The UL CA architecture may further include a second RF circuit configured to route a second TX signal to the second antenna port to provide UL CA capability between the first and second TX signals.