Serpentine Cable Antenna for Omnidirectional RFID Tag Reading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing handheld radio communication reader devices have a complex structure and limited directional emission of electromagnetic waves, making them inefficient for wide-area radio communication with RFID tags.
Innovation Solution
A cable antenna with a serpentine configuration and exposed outer conductor sections that radiate electromagnetic waves in all directions, allowing for efficient communication with RFID tags arranged around it, using a high-frequency current and specific wavelength alignment for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a handheld radio communication reader device is used, then radio communication with RFID tags can be performed, but the structure becomes complicated and electromagnetic wave emission is limited to specific directions
Solution Approach 1:
The invention divides the antenna into multiple segments along its length, with alternating sections of outer conductor present and absent. This segmentation creates multiple radiation sources along the cable that collectively emit electromagnetic waves in all directions, resolving the contradiction between directional limitation and structural complexity
Solution Approach 2:
The invention transitions from a point-source or directional antenna model to a distributed linear array model. By extending the radiation sources along the length of the cable antenna and spacing them appropriately, the system achieves omnidirectional radiation coverage in three-dimensional space without requiring complex multi-element arrays
2Power
If the outer conductor is removed to form an exposed part, then electromagnetic waves can be radiated efficiently in all directions, but the cable structure becomes less protected
Solution Approach 1:
The invention applies different structural qualities to different sections of the cable antenna. In radiation sections, the outer conductor is removed to enable efficient electromagnetic wave emission. In non-radiation sections, the outer conductor remains intact to provide mechanical protection and electrical shielding. This local differentiation resolves the contradiction between radiation efficiency and structural protection
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 cable antenna enables efficient electromagnetic wave radiation in all directions with a simple configuration, improving communication efficiency and accommodating RFID tags in various orientations, suitable for low-cost RFID tag systems and merchandise management.
Implementation Method 1
A cable antenna with a serpentine configuration and exposed outer conductor sections that radiate electromagnetic waves in all directions, allowing for efficient communication with RFID tags arranged around it, using a high-frequency current
Data Source
AI summary
A cable antenna an end part of which is connected to an oscillator that supplies a high-frequency current is disclosed. The cable antenna includes: an inner conductor; an insulating layer covering the inner conductor; and an outer conductor covering the insulating layer, wherein only one exposed part is formed in a middle part of the cable antenna in a longitudinal direction, the exposed part formed by removing at least the outer conductor, a distance L between a tip end of the cable antenna and an end of the exposed part on a side closer to the tip end is an odd multiple of a quarter of a wavelength λ, of the high-frequency current, the multiplier being three or greater, and a length G of the exposed part in the longitudinal direction satisfies the following formula (1):λ/20≤G<λ/4 (1)λ: wavelength (mm) of the high-frequency current.