Multi-Band Transmitter Architecture With Shared PA and Pre-Distortion
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Solution Overview
Problem
Existing wireless transmitters require multiple circuit blocks to support various modulation schemes and frequency bands, leading to increased cost and power consumption due to replication of circuit blocks for each combination of modulation scheme and frequency band.
Innovation Solution
The design of transmitters that share circuit blocks across different modulation modes, such as large signal polar modulation, small signal polar modulation, and quadrature modulation, and apply pre-distortion to power amplifiers to operate efficiently across multiple frequency bands, compensating for non-linearity using stored characterizations of envelope and phase distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If circuit blocks are replicated for each combination of modulation scheme and frequency band, then performance for each modulation scheme and frequency band is improved, but cost and power consumption increase
Solution Approach 1:
The patent implements a universal transmitter architecture where a single power amplifier and modulator can operate across multiple frequency bands and modulation schemes. The power amplifier is designed to be frequency-agile, supporting both LTE and NR frequency ranges, while the modulator handles multiple modulation types (QPSK, QAM, etc.). This multi-functional design eliminates the need for separate circuit blocks for each modulation scheme and frequency band combination, thereby reducing power consumption while maintaining performance across all supported modes.
Solution Approach 2:
The patent merges previously separate circuit blocks into a unified transmitter structure. Specifically, multiple power amplifiers for different frequency bands are consolidated into a single frequency-agile power amplifier. Similarly, separate modulators for different modulation schemes are combined into a single multi-mode modulator. This merging reduces the total number of active components, lowering overall power consumption while preserving the ability to support diverse modulation schemes and frequency bands.
2Reliability
If circuit blocks are replicated for each combination of modulation scheme and frequency band, then performance for each modulation scheme and frequency band is improved, but device cost increases
Solution Approach 1:
The patent employs universal circuit blocks that can operate across multiple frequency bands and modulation schemes. The frequency-agile power amplifier and multi-mode modulator are designed to handle LTE, NR, and other wireless standards with different frequency ranges and modulation requirements. This universality reduces the bill of materials by eliminating redundant components, thereby lowering manufacturing cost while maintaining the performance needed for each specific modulation scheme and frequency band combination.
Solution Approach 2:
The patent combines multiple specialized circuit blocks into fewer multi-functional blocks. Instead of having separate power amplifiers for LTE and NR bands, a single frequency-agile power amplifier is used. Similarly, separate modulators for different modulation schemes are merged into one modulator that supports multiple modes. This consolidation reduces component count and assembly complexity, leading to lower manufacturing costs while preserving the ability to deliver high performance across all supported standards.
3Device complexity
If a single power amplifier is used for multiple frequency bands, then device complexity is reduced, but the power amplifier must operate at higher output power levels which increases power consumption
Solution Approach 1:
The patent utilizes parameter changes to optimize power amplifier operation across different frequency bands. The frequency-agile power amplifier dynamically adjusts its operating parameters (such as bias conditions, gain settings, and output power levels) based on the active frequency band and modulation scheme. This adaptive parameter adjustment allows the single power amplifier to operate efficiently across multiple bands without requiring excessive output power, thereby reducing power consumption while maintaining low device complexity.
Solution Approach 2:
The patent implements dynamic operation of the power amplifier to adapt to different frequency bands and transmission conditions. The power amplifier's characteristics are dynamically adjusted through digital signal processing and control mechanisms that optimize its performance for each specific operating mode. This dynamic adaptation enables the single power amplifier to maintain efficiency across multiple frequency bands, avoiding the need to operate at consistently high power levels and thereby reducing overall power consumption while keeping the device architecture simple.
Data Source
AI summary
Transmitters supporting multiple modulation modes and/or multiple frequency bands are described. A transmitter may perform large signal polar modulation, small signal polar modulation, and/or quadrature modulation, which may support different modulation schemes and systems. Circuit blocks may be shared by the different modulation modes to reduce cost and power. For example, a single modulator and a single power amplifier may be used for small signal polar modulation and quadrature modulation. The transmitter may apply pre-distortion to improve performance, to allow a power amplifier to support multiple frequency bands, to allow the power amplifier to operate at higher output power levels, etc. Envelope and phase distortions due to non-linearity of the power amplifier may be characterized for different input levels and different bands and stored at the transmitter. Thereafter, envelope and phase signals may be pre-distorted based on the stored characterizations to compensate for non-linearity of the power amplifier.