Thin Film Balun Resonant Frequency Control via Capacitor Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thin film baluns face challenges in maintaining a required resonant frequency and balance characteristics when size and thickness are reduced, leading to increased resonant frequency and degraded balance characteristics, which cannot satisfy specifications for wireless communication devices.
Innovation Solution
Incorporating at least a part of the capacitance component within the area of the second magnetic coupling, specifically on the side of the second magnetic coupling with respect to the boundary between the first and second magnetic couplings, to suppress the increase in resonant frequency and improve balance characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the number of turns or length of lines of coils is reduced to decrease size and thickness, then the device size and thickness are reduced, but the inductance L decreases and resonant frequency fr increases to high frequency, failing to meet specification requirements
Solution Approach 1:
The patent changes the physical parameters of the transmission lines by increasing their width and adjusting their layout configuration. This allows maintaining sufficient inductance L with fewer turns, thereby keeping resonant frequency fr within the required range while achieving reduced device size and thickness.
Solution Approach 2:
The patent utilizes planar transmission line structures with optimized width and spacing in the XY plane, transitioning from traditional vertical coil stacking to a two-dimensional layout approach. This enables size reduction while maintaining electrical performance through careful control of line dimensions and coupling geometry.
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 configuration effectively prevents the resonant frequency from increasing and enhances the balance characteristics, ensuring a preferable passage characteristic and output balance, thus meeting the specifications for wireless communication devices.
Implementation Method 1
the first line portion and the third line portion form a first magnetic coupling
Implementation Method 2
the second line portion and the fourth line portion form a second magnetic coupling
Data Source
AI summary
The present invention provides a thin film balun capable of preventing a resonant frequency from being increased to a high frequency due to size and thickness reductions and maintaining a preferable passage characteristic, while improving a balance characteristic. A thin film balun 1 includes: an unbalanced transmission line 2 having a first coil portion C1 and a second coil portion C2; and a balanced transmission line 3 having a third coil portion C3 and a fourth coil portion C4 which are magnetically coupled with the first coil portion C1 and the second coil portion C2, respectively. The first coil portion C1 is connected to an unbalanced terminal T0, and the second coil portion C2 is connected to a ground terminal G (ground potential) via a capacitor D (C component). The third coil portion C3 is connected to a balanced terminal T1 and the fourth coil portion C4 is connected to a second balanced terminal T2. At least a part of the capacitor D is contained in a second magnetic coupling area R2 formed by the coil portions C2 and C4.