Wireless IC Resonant Circuit Segmentation for Frequency Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wireless IC devices for RFID systems face challenges in maintaining stable resonant frequency properties due to positional deviations and shape changes, especially when mounted on large-area plastic films or sandwiched between dielectric members.
Innovation Solution
A wireless IC device design featuring a wireless IC chip and a power supply circuit board with a resonant circuit, where the chip and board are disposed parallel to each other on a wiring board, connected via a conductor, and the power supply circuit board includes a radiation pattern to radiate and receive signals, ensuring frequency stability regardless of the antenna's shape or placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wireless IC chip is mounted on a large-area plastic film using an Au bump in a DC manner, then the connection between the chip and antenna is established, but it becomes extremely difficult to mount the chip precisely due to the large area, causing positional deviation that changes resonant frequency properties
Solution Approach 1:
The invention divides the system into two separate functional parts: a rigid circuit board containing the wireless IC chip and power supply circuit, and a flexible radiation pattern portion. This segmentation allows the chip to be mounted precisely on the small rigid board rather than attempting to mount it directly on the large flexible film, thereby solving the positioning precision problem while maintaining connection reliability through the connector interface between the two segments.
Solution Approach 2:
The rigid circuit board acts as an intermediary between the wireless IC chip and the flexible radiation pattern. Instead of mounting the chip directly on the large flexible film (which causes positioning difficulties), the chip is mounted on the rigid board which provides a stable, small mounting area. The rigid board then connects to the flexible radiation pattern through a connector, serving as a mediator that transfers signals while maintaining both positioning precision and flexibility.
2Adaptability or versatility
If the antenna pattern is rounded or sandwiched between dielectric members, then the device can be inserted into books or rounded, but the resonant frequency properties at the antenna are changed
Solution Approach 1:
The invention separates the frequency-determining circuitry (resonant circuit and wireless IC chip) from the radiation pattern into distinct segments. The resonant circuit is mounted on a rigid circuit board that maintains its shape and electrical properties regardless of external deformation. The flexible radiation pattern portion can be rounded or sandwiched without affecting the resonant frequency, as the frequency is determined by the rigid circuit board components rather than the deformed antenna shape.
Solution Approach 2:
The invention applies different structural qualities to different parts of the system: the circuit board portion is made rigid to maintain stable electrical properties and resonant frequency, while the radiation pattern portion is made flexible to enable insertion into books or rounded objects. This local differentiation of rigidity allows the device to achieve both frequency stability and physical adaptability simultaneously.
3Adaptability or versatility
If the wireless IC chip is mounted on a large-area film, then the device can be made flexible for insertion, but it is extremely difficult to determine and mount the position of the small wireless IC chip on the film
Solution Approach 1:
The invention divides the manufacturing process into two separate mounting operations: first, mounting the wireless IC chip on the small rigid circuit board (which is easy due to the small area and rigid surface), and second, connecting the rigid circuit board to the flexible radiation pattern through a connector. This segmentation transforms a difficult single-step mounting process into two easier sequential steps, greatly improving ease of manufacture while maintaining device flexibility.
Solution Approach 2:
The rigid circuit board serves as an intermediary that decouples the mounting difficulty from the flexibility requirement. The chip is mounted on the rigid board (easy mounting), which then connects to the flexible radiation pattern (provides flexibility). This intermediary structure eliminates the need to mount the chip directly on the large flexible surface, thereby improving ease of manufacture while preserving the desired flexibility for insertion.
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 ensures stable frequency properties for transmission and reception signals, allowing precise mounting of the wireless IC chip and improved antenna gain, even when the device is rounded or sandwiched, by determining signal frequencies based on the resonant circuit rather than the antenna's shape or position.
Implementation Method 1
a power supply circuit which includes a resonant circuit having a predetermined resonant frequency
Implementation Method 2
a radiation pattern to which the power supply circuit board is attached or disposed adjacent, the radiation pattern being arranged to radiate a transmission signal supplied from the power supply circuit, and/or to receive a reception signal
Data Source
AI summary
A wireless IC device includes a wireless IC chip, a power supply circuit board upon which the wireless IC chip is mounted, and in which a power supply circuit is provided, the power supply circuit includes a resonant circuit having a predetermined resonant frequency, and a radiation pattern, which is adhered to the underside of the power supply circuit board, for radiating a transmission signal supplied from the power supply circuit, and for receiving a reception signal to supply this to the power supply circuit. The resonant circuit is an LC resonant circuit including an inductance device and capacitance devices. The power supply circuit board is a multilayer rigid board or a single-layer rigid board, and between the wireless IC chip and the radiation pattern is connected by DC connection, magnetic coupling, or capacitive coupling.