RF Power Supply Modulation With Precalibrated Delay Alignment
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Solution Overview
Problem
Existing wireless communication devices face challenges in achieving high efficiency and accuracy in power supply modulation of radio frequency signals, particularly due to fixed power supply voltage in RFPA, leading to inefficiencies and signal distortion, and require a method for amplitude and time alignment that is programmable and independent of fixed delays in the I/Q path.
Innovation Solution
A method and apparatus that determine and store exciter module and power supply modulation delay factors for each signal modulation scheme, allowing for generation of RF signals and power supply voltages that align without the need for repeated calibration, enabling efficient and accurate power supply modulation independent of fixed delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If envelope tracking is used to modulate the power supply of RFPA, then amplifier efficiency is improved, but device complexity increases due to additional modulation circuits and calibration requirements
Solution Approach 1:
The patent uses a lookup table to store pre-calibrated delay factors for different modulation schemes, copying calibration results into a accessible format that eliminates the need for repeated complex calibration procedures. This reduces device complexity while maintaining the efficiency benefits of envelope tracking.
Solution Approach 2:
The patent performs calibration once during manufacturing or initial setup, storing the delay factors in advance. This preliminary action eliminates the need for repeated calibration cycles during operation, reducing both device complexity and operational overhead while preserving amplifier efficiency.
2Reliability
If margin is added to the supply voltage of RFPA, then reliability is improved by preventing starvation, but amplifier efficiency decreases due to reduced average efficiency
Solution Approach 1:
The patent dynamically adjusts the power supply voltage to match the instantaneous envelope of the RF signal, allowing the amplifier to operate near saturation across varying signal conditions. This dynamic adjustment maintains reliability by preventing supply starvation while maximizing efficiency by avoiding the need for a fixed voltage margin.
3Measurement precision
If fixed hardware delay elements are added to align envelope and RF signals, then time alignment accuracy is improved, but manufacturing cost increases and device complexity increases
Solution Approach 1:
The patent replaces physical hardware delay elements with programmable delay factors stored in a lookup table. This substitution eliminates the need for additional physical components while maintaining time alignment accuracy, thereby reducing device complexity and manufacturing cost.
Solution Approach 2:
The patent adjusts the delay parameter through software-based lookup tables rather than fixed hardware configurations. This allows flexible adjustment of time alignment for different modulation schemes without requiring physical hardware changes, reducing both device complexity and manufacturing costs while maintaining precision.
4Measurement precision
If repeated calibration cycles are performed for each modulation scheme, then amplitude and time alignment accuracy is improved, but productivity decreases due to time-consuming calibration
Solution Approach 1:
The patent performs calibration once during manufacturing or initial setup, storing the delay factors for multiple modulation schemes in advance. This preliminary action eliminates the need for repeated calibration cycles during operation, significantly improving productivity while maintaining alignment accuracy through the stored lookup table.
Solution Approach 2:
The patent copies calibration results into a lookup table that can be quickly accessed for different modulation schemes. This copying approach eliminates the need to repeat the calibration process for each scheme, maintaining accuracy while dramatically improving productivity by enabling instant retrieval of calibrated parameters.
Data Source
AI summary
A transmitter power supply modulates an RF signal without needing to run a calibration/training cycle every time an exciter or PA module is switched in and out or every time the transmitter powers up. During calibration of the exciter module, an exciter module delay factor is determined, and stored in the exciter module, for each signal modulation scheme that may be implemented by the exciter module. During calibration of a power amplifier (PA) module, a power supply modulation (PSM) delay factor is determined for, and stored in, the PA module. During transmitter operation, the exciter module generates RF and envelope signals based on an input signal. The PA module generates a power supply voltage based on the envelope signal and a final delay factor, which final delay factor is based on the exciter module and PSM delay factors. The PA module then modulates the RF signal using the power supply voltage.