Multi-Output Amplifier With Configurable Degeneration Inductor
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Solution Overview
Problem
Current amplifiers for wireless devices face challenges in efficiently supporting carrier aggregation with multiple outputs, particularly in maintaining gain, dynamic range, and input matching across different operating modes, which affects their performance in receiving multiple transmitted signals concurrently.
Innovation Solution
The development of multi-output amplifiers with configurable source degeneration inductance allows for adjustable bias currents and inductance settings, enabling the amplifiers to maintain performance in both single-output and multi-output modes by reducing the degeneration inductance in the multi-output mode to boost gain and improve input matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the amplifier operates in multi-output mode with fixed degeneration inductance, then it can support carrier aggregation, but the gain and input matching deteriorate
Solution Approach 1:
The patent applies the dynamics principle by making the degeneration inductance value adjustable based on the operating mode. The inductance is configured to be reduced when operating in multi-output mode compared to single-output mode, allowing the amplifier to dynamically adapt its electrical characteristics to maintain optimal performance across different operational states.
Solution Approach 2:
The patent implements parameter changes by varying the degeneration inductance value according to the number of active outputs. Specifically, the degeneration inductance is set to a first value for single-output mode and a second (lower) value for multi-output mode, thereby changing the electrical parameters to optimize gain and input matching for each operating condition.
2Reliability
If the degeneration inductance is increased to improve linearity, then the dynamic range improves, but the gain decreases
Solution Approach 1:
The patent resolves this contradiction by dynamically adjusting the degeneration inductance value based on the operating mode requirements. In single-output mode, a higher inductance value is used to maximize linearity and dynamic range. In multi-output mode, a lower inductance value is selected to prioritize gain while maintaining adequate linearity, thus adapting the trade-off between these two parameters according to operational needs.
Solution Approach 2:
The patent changes the degeneration inductance parameter to different discrete values depending on the number of active outputs. This parameter change allows the system to optimize the balance between linearity and gain for each specific operating mode, rather than being constrained by a fixed inductance value that would compromise one parameter to achieve the other.
3Manufacturing precision
If separate input matching circuits are used for each output mode, then the input matching performance improves, but the device complexity increases
Solution Approach 1:
The patent applies the universality principle by using a single input matching circuit that serves multiple output modes. Rather than designing separate matching circuits for each operating mode, the patent achieves mode-specific matching performance through the configurable degeneration inductance, allowing one circuit structure to fulfill multiple functions across different operational states.
Solution Approach 2:
The patent uses parameter changes in the degeneration inductance to achieve different input matching characteristics without requiring separate matching circuits. By adjusting the inductance value based on the operating mode, the same input matching circuit can be optimized for different modes, thereby maintaining high input matching performance while avoiding the complexity of multiple dedicated circuits.
Data Source
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AI summary
Multi-output amplifiers with configurable source degeneration inductance and having good performance are disclosed. In an exemplary design, an apparatus (e.g., a wireless device or an integrated circuit) includes a gain transistor (534) and a configurable degeneration inductor (520) for an amplifier (500). The gain transistor (534) receives an input signal and provides an amplified signal. The amplifier (500) provides a single output signal in a first operating mode or a plurality of output signals in a second operating mode. The configurable degeneration inductor (520) is coupled to the gain transistor (534) and provides a first source degeneration inductance in the first operating mode or a second source degeneration inductance in the second operating mode. The second source degeneration inductance is less than the first source degeneration inductance and may be dependent on the number of output signals generated in the second operating mode.