Monolithic Doherty Power Splitter for Phase-Coherent Isolation
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Solution Overview
Problem
Modern wireless communication systems, particularly in 4G and 5G, face challenges in designing RF power amplifiers that operate at low power output back-off while maintaining linearity and high power added efficiency, especially with high peak-to-average power ratio signals, which existing Doherty power amplifier configurations struggle to meet due to complexity and integration requirements.
Innovation Solution
A monolithic power splitter integrated with a Doherty power amplifier on a single semiconductor die, featuring multiple branches with pre-driver amplifiers and adjustment elements, such as transmission lines or lumped-element delay circuits, to achieve electrical isolation and phase coherence across frequency bands, allowing for efficient power distribution between main and peaking amplification paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If discrete packaging and PCB substrate coupling are used for power amplifiers, then ease of manufacture is improved, but device complexity increases and integration level decreases
Solution Approach 1:
The patent integrates the power splitter and multiple power amplifiers into a single monolithic semiconductor device, combining previously separate components (splitter on PCB, amplifiers in discrete packages) into one unified structure. This merging reduces the number of external connections and inter-component interfaces, thereby reducing device complexity while maintaining manufacturability through standard semiconductor fabrication processes.
Solution Approach 2:
The monolithic device performs multiple functions within a single integrated structure: signal splitting across multiple branches, independent amplification in each branch, and combined output. The power splitter portion and amplifier portions share the same semiconductor substrate and fabrication process, enabling universal manufacturing while achieving high integration.
2Productivity
If high levels of integration are achieved, then productivity and efficiency are improved, but manufacturing precision requirements increase
Solution Approach 1:
The monolithic device is segmented into distinct functional portions: a power splitter portion with multiple branches and amplifier portions, each branch containing an amplifier. This segmentation allows each portion to be optimized independently during fabrication while maintaining overall integration, reducing the precision requirements compared to a fully monolithic structure without internal segmentation.
Solution Approach 2:
Different portions of the monolithic device can have different local characteristics optimized for their specific functions. The power splitter portion and amplifier portions can use different material compositions, doping profiles, or geometric structures tailored to their respective requirements, allowing high integration while managing manufacturing precision through localized optimization.
Data Source
AI summary
Aspects of the subject disclosure may include a power splitter. The power splitter can include a first splitter branch having a first amplifier with passive components, a second splitter branch having a second amplifier with passive components. The first splitter branch is substantially electrically isolated from the second splitter branch by configuring the first and second splitter branches to have similar phase delays. Outputs of the power splitter can be electrically coupled to the multi-stage amplifier. The power splitter can be manufactured on a single semiconductor die or integrally formed on the same semiconductor die with other circuits such as the multi-stage amplifier. Other embodiments are disclosed.