Receiver Power Network Switching for Inter-Carrier Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
State-of-the-art transceivers face challenges in achieving robust signal isolation between carriers in a shared power distribution network, particularly at high frequencies, due to the weak power supply rejection ratio of low dropout (LDO) voltage regulators, which degrades receiver performance in carrier-aggregation systems.
Innovation Solution
The implementation of a selective coupling and decoupling architecture using switches in conjunction with transformers and a shared power distribution network, allowing for improved inter-carrier aggregation (inter-CA) isolation by selectively enabling or disabling the coupling of transformers to the power network based on active signal paths, thereby reducing signal interference without relying on decoupling capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a shared power distribution network with LDO voltage regulators is used to reduce the number of power pins, then device complexity and pin count are reduced, but inter-carrier isolation deteriorates at high frequencies
Solution Approach 1:
The shared power distribution network is segmented into multiple isolated power domains using switching elements. Each carrier path (CA1, CA2) has its own switched connection to the LDO regulators, allowing independent control of power delivery. This segmentation enables the system to maintain a shared power architecture while preventing interference between carriers through selective isolation of power paths.
Solution Approach 2:
The power distribution network transitions from a static shared connection to a dynamic switched architecture. Switching elements dynamically connect or disconnect specific carrier paths from specific LDO regulators based on which carriers are actively receiving signals. This dynamic control allows the system to adapt the power distribution topology in real-time, providing isolation when needed while maintaining sharing when beneficial.
2Object-affected harmful factors
If decoupling capacitors are added to improve high-frequency isolation between LDOs, then inter-carrier isolation improves, but device area and complexity increase
Solution Approach 1:
Switching elements are introduced as intermediary components between the LDO regulators and the carrier paths. These switches act as controllable isolators that can block interference propagation without requiring large decoupling capacitors. The switching elements provide high-frequency isolation through their inherent off-state impedance characteristics rather than relying on capacitor-based filtering, thereby reducing the area required for isolation components.
3Object-affected harmful factors
If multiple independent power distribution networks are used for each carrier, then inter-carrier isolation improves, but device complexity and pin count increase
Solution Approach 1:
Multiple power distribution networks are merged into a single shared power distribution network that serves all carrier paths. The sharing is enabled through switching elements that dynamically allocate power from the shared LDO regulators to different carriers based on their active state. This merging reduces the total number of power pins and LDO regulators required while maintaining isolation performance through the switching control mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances inter-CA isolation, maintaining performance across high frequencies with minimal power consumption and area overhead, effectively addressing the limitations of shared LDO power systems in transceiver designs.
Implementation Method 1
a first low noise amplifier (LNA) circuit output, a second LNA circuit output
Data Source
Figure 1
Figure 2A~2D
Figure 3
AI summary
A device includes a first amplifier circuit coupled to a first transformer and a second transformer, the first transformer selectively coupled to a first shared power distribution network through a first switch, the second transformer selectively coupled to a second shared power distribution network through a second switch.