Tunable Inductor Layout With Vertical Shielding for Lower Mutual Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tunable inductors in advanced communication applications, such as Wi-Fi 7 and 5G, face issues with low quality factor (Q factor) and high mutual inductance, leading to performance degradation and increased power consumption.
Innovation Solution
A semiconductor device with a first inductor and a second inductor connected in series, where the second inductor has vertical portions perpendicular to the first inductor, acting as a patterned shield when off to enhance Q factor, and as a secondary inductor when on to reduce mutual inductance and broaden tuning range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a tunable inductor is designed with secondary inductor for inductance adjustment, then the tuning range is improved, but the mutual inductance increases causing performance degradation
Solution Approach 1:
A patterned floating shield structure is introduced as an intermediary element positioned between the first inductor and second inductor. This shield acts as a mediator to block magnetic field coupling, thereby reducing mutual inductance between the two inductors while preserving the desired tuning range adjustment capability
Solution Approach 2:
The patent converts the harmful mutual inductance effect into a beneficial configuration by using the second inductor's vertical portions to create the patterned floating shield structure. When the second inductor is disconnected, its vertical portions form a shield that blocks magnetic interference, transforming the potential source of mutual inductance into a protective element
2Device complexity
If a tunable inductor uses conventional layout, then the device complexity is reduced, but the quality factor (Q factor) decreases due to magnetic loss
Solution Approach 1:
The second inductor is configured with vertical portions that extend perpendicular to the plane of the first inductor. This three-dimensional arrangement creates a patterned floating shield structure that effectively blocks magnetic field lines, reducing magnetic loss and improving Q factor without significantly increasing device complexity
Solution Approach 2:
The patent applies the patterned floating shield configuration specifically in the regions where magnetic coupling occurs between inductors. The vertical portions of the second inductor are strategically positioned to provide localized magnetic field blocking, reducing loss at critical areas without requiring complete structural redesign
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
The design improves the quality factor of the inductor when off and reduces mutual inductance when on, enhancing performance and tuning range while minimizing magnetic loss and power consumption.
Implementation Method 1
the second inductor has vertical portions perpendicular to the first inductor, acting as a patterned shield when off to enhance Q factor
Implementation Method 2
LC tanks, which consist of an inductor and a capacitor, are widely used in RF/mm-wave circuits
Data Source
AI summary
A semiconductor device is provided. The semiconductor device includes a first port, a second port, a first inductor, a second inductor and a switch circuit. The first inductor is coupled between a first port and a second port. The first inductor includes a first strip part close to the first port. The second inductor and the switch circuit are connected in series. The series connected second inductor and the switch circuit are coupled between the first port and the second port and overlap the first inductor. The second inductor includes at least one first vertical portion that overlaps and is perpendicular to the first strip part.