Balanced RF Power Amplifier With Adjustable Quadrature Combining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio frequency power amplifiers face challenges in meeting the increased linear power requirements for mobile high-power user equipment (HPUE) functions, particularly in higher frequency bands like Band41, due to reduced gain and increased load impedance voltage standing wave ratio (VSWR) of radio frequency antennas, and existing solutions either require complex implementations or suffer from parasitic parameters and output power losses.
Innovation Solution
A balanced radio frequency power amplifier structure that includes a 90-degree power splitter and adjustable 90-degree power combiner, utilizing multiple power stages and a control unit to optimize phase and amplitude differences between input signals, minimizing sensitivity to load changes and enhancing output linear power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the area of the output power tube is increased to improve output current capability, then the output current capability is improved, but excessively large parasitic parameters are caused which deteriorate high-frequency performance
Solution Approach 1:
The patent divides the power amplification function into multiple parallel power amplifier units instead of using a single large power tube. Each unit operates independently with its own impedance matching network, allowing the system to achieve high output current capability while maintaining small individual tube areas that avoid excessive parasitic parameters. This segmentation enables high-frequency operation to be maintained while providing the required total output power.
2Power
If constant power supply voltage increase is applied to improve linear power, then implementation is simple, but power added efficiency at backoff power is reduced and power supply booster is required
Solution Approach 1:
The patent employs dynamic impedance adjustment through variable impedance matching networks that can adapt their impedance values based on the operating conditions. This dynamic adjustment allows the power amplifier to maintain optimal power transfer and efficiency across different output power levels including backoff conditions, eliminating the need for constant high voltage operation and its associated efficiency penalties.
Solution Approach 2:
The patent changes the impedance parameters of the matching networks dynamically to optimize performance at different power levels. By adjusting impedance values rather than maintaining constant high voltage, the system achieves improved linear power output while maintaining high power added efficiency even at backoff conditions, avoiding the need for additional power supply boosters.
3Power
If parallel connection of multiple power amplifiers is used to increase output current, then parasitic parameter problem is avoided, but output power loss caused by antenna load impedance change cannot be resolved
Solution Approach 1:
The patent incorporates variable impedance matching networks in each parallel power amplifier unit that can dynamically adjust their impedance parameters in response to load changes. When antenna load impedance changes occur, these adaptive matching networks modify their impedance values to compensate for the variation, thereby maintaining stable output power levels across changing operating conditions while preserving the benefits of parallel amplifier architecture.
4Speed
If higher frequency band is used for HPUE function, then communication speed requirement is met, but performance is deteriorated by larger parasitic parameters
Solution Approach 1:
The patent segments the power amplification function into multiple parallel units, each with small individual power tubes that have minimal parasitic parameters suitable for high-frequency operation. By distributing the total power requirement across multiple small units rather than using a single large tube, the system achieves the required communication speed performance in higher frequency bands while avoiding the parasitic parameter deterioration that would occur with larger individual tubes.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Disclosed in the present invention are a balanced radio frequency power amplifier, a chip and a communication terminal. The radio frequency power amplifier divides, by means of a 90-degree power splitter unit, a radio frequency input signal into two equal-amplitude signals having a phase difference of 90 degrees, the two radio frequency input signals are amplified and then inputted into an adjustable 90-degree power combiner, and the values of a adjustable capacitor and an adjustable resistor in the adjustable 90-degree power combiner are controlled by means of a control unit, so as to synthesize the two radio frequency input signals into one radio frequency input signal when the phase difference and amplitude difference of the two signals at different frequencies are the smallest, and to input the radio frequency input signal into a circuit of the next stage by means of a specific radio frequency transmission path. The balanced radio frequency power amplifier not only increases the maximum linear power of the output, but also reduces the sensitivity to a change in the radio frequency antenna load, thereby supporting functions of mobile high performance user equipment.