Cascode Divert LNA Architecture for Carrier Aggregation
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Solution Overview
Problem
Existing low noise amplifiers (LNAs) face challenges in efficiently supporting carrier aggregation in wireless communication devices, particularly in managing multiple carriers across different frequency bands, which affects signal amplification and noise reduction.
Innovation Solution
The development of LNAs with cascode divert switch architectures and inductive degeneration, enabling multi-output modes for intra-band and inter-band carrier aggregation, and supporting MIMO operations to effectively amplify and process signals across various frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing LNA architectures are used, then device complexity is reduced, but the ability to support carrier aggregation across multiple frequency bands is insufficient
Solution Approach 1:
The LNA is divided into multiple parallel amplifier circuits (first amplifier circuit, second amplifier circuit, third amplifier circuit) that can be independently activated. Each amplifier circuit is designed to handle specific frequency bands, allowing the LNA to support carrier aggregation across multiple bands by selectively enabling the appropriate circuits based on the received signal's frequency characteristics.
Solution Approach 2:
The LNA employs dynamic switching mechanisms including cascode divert switches and inductive degeneration circuits that can be activated or deactivated based on the operating frequency band. This dynamic reconfiguration allows the same LNA hardware to adaptively support different carrier aggregation scenarios (intra-band and inter-band) without requiring separate dedicated circuits for each band.
2Adaptability or versatility
If multiple amplifier circuits are added for carrier aggregation, then adaptability improves, but device complexity increases
Solution Approach 1:
Each amplifier circuit is designed with universal functionality to handle multiple frequency bands through the cascode divert switch architecture. The inductive degeneration circuits and cascode switches can be dynamically configured to route signals appropriately, allowing the same physical circuit to serve multiple purposes across different bands, thereby reducing the need for completely separate dedicated circuits for each band.
Solution Approach 2:
The patent combines multiple amplifier circuits, cascode divert switches, and inductive degeneration circuits into a single integrated LNA module. This merging approach allows the circuits to share common components such as the input terminal, output terminal, and control logic, reducing overall device complexity compared to having completely separate LNAs for each frequency band.
3Reliability
If cascode divert switches and inductive degeneration are implemented, then gain and noise figure improve, but manufacturing complexity increases
Solution Approach 1:
The inductive degeneration circuits and cascode divert switches enable dynamic parameter changes in the amplifier circuits based on the operating frequency band. By adjusting the inductance values and switch configurations, the LNA can optimize its gain, noise figure, and impedance matching for different frequency bands, improving overall signal amplification quality while using standard semiconductor fabrication processes.
Data Source
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AI summary
Low noise amplifiers (LNAs) supporting carrier aggregation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes first and second amplifier circuits and a divert cascode transistor. Each amplifier circuit may include a gain transistor and a cascode transistor. The divert cascode transistor is coupled between the output of the first amplifier circuit and the gain transistor in the second amplifier circuit. The first and second amplifier circuits receive an input radio frequency (RF) signal including transmissions sent on multiple carriers at different frequencies to a wireless device. The first and second amplifier circuits and the divert cascode transistor are controlled to amplify the input RF signal and provide (i) one amplified RF signal for one set of carriers in a first operating mode or (ii) two amplified RF signals for two sets of carriers in a second operating mode.