Outphasing RF Circuit With Signal Splitting for Power Back-Off Efficiency
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Solution Overview
Problem
Conventional dual-input radio frequency circuits suffer from reduced efficiency between power back-off and high power points, leading to increased energy consumption and high costs due to the need for additional transmit channels, which complicates large-scale application and optimization of power amplification efficiency.
Innovation Solution
A radio frequency circuit design that includes a first circuit for splitting and phase-adjusting input signals to optimize the parameters of a secondary power amplifier branch, allowing for flexible adjustment of input signals to achieve maximum efficiency and reduce the size and cost of the circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a composite radio frequency circuit combining DHT circuit and outphasing circuit is used, then power amplification efficiency between power back-off point and high power point is improved, but the quantity of input signals increases from two to three, making the circuit size excessively large and requiring three transmit channels
Solution Approach 1:
The patent merges the DHT circuit and outphasing circuit into a composite radio frequency circuit, combining their respective advantages. The outphasing circuit serves as the primary power amplifier of the DHT circuit, integrating two previously separate circuits into one unified system that achieves improved power amplification efficiency while managing complexity through functional integration
Solution Approach 2:
The composite radio frequency circuit is designed to perform multiple functions: it operates as both an outphasing circuit and a DHT circuit simultaneously. By making the primary power amplifier branch capable of dual functionality, the circuit reduces the need for separate dedicated circuits for different operating modes, thereby improving efficiency across multiple power levels without proportionally increasing overall complexity
2Device complexity
If signals from two transmit channels are converted into three input signals by splitting or combination, then the quantity of transmit channels is reduced, but at least one input signal cannot be adjusted to an expected value, preventing optimal power amplification efficiency at rated power
Solution Approach 1:
The patent introduces dynamic adjustment capabilities through phase shifters and variable gain amplifiers in the signal processing paths. These dynamic components allow the circuit to adaptively adjust signal phases and amplitudes in real-time, ensuring that all three input signals to the composite RF circuit can be precisely controlled to their expected values across different operating conditions, thereby maintaining optimal power amplification efficiency
Solution Approach 2:
The patent employs parameter adjustment mechanisms including phase shifting and gain control to modify the characteristics of input signals. By changing phase and amplitude parameters of the signals from the two transmit channels before they are combined and distributed to the three input paths, the circuit achieves precise control over each input signal's characteristics, enabling optimal efficiency while using fewer transmit channels
Data Source
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AI summary
Embodiments of the present invention provide a radio frequency circuit, including: a first circuit and a second circuit. The first circuit is configured to: receive a first signal and a second signal; split the first signal into a third signal and a fourth signal, and split the second signal into a fifth signal and a sixth signal; adjust a phase of the fifth signal to obtain a seventh signal; and combine the seventh signal and the third signal into an eighth signal. The second circuit includes a primary power amplifier branch and a secondary power amplifier branch, the primary power amplifier branch includes an outphasing circuit, the secondary power amplifier branch includes a secondary power amplifier, the primary power amplifier branch is configured to process the fourth signal and the sixth signal, and the secondary power amplifier branch is configured to process the eighth signal. In the radio frequency circuit provided in the embodiments of the present invention, the second circuit at rated power can reach highest efficiency, so that an actual application requirement can be satisfied.