Low Loss Antenna Cover Using Diamond-Like Coating
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Solution Overview
Problem
Existing portable radio device antennas suffer from radio frequency losses due to the materials used in the outer cover, which also lead to local heating issues when transmitting at full power, causing user discomfort and potential misinterpretation of device malfunction.
Innovation Solution
The outer cover of portable radio devices is made partly of a very low loss thermoplastic material with a diamond-, diamond-like, or nanocomposite coating, reducing the loss tangent value to less than 0.005 and enhancing mechanical strength and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional injection molded cover materials are used, then manufacturing ease and mechanical properties are maintained, but radio frequency losses increase and antenna efficiency decreases
Solution Approach 1:
The patent applies composite materials by combining a low-loss thermoplastic material base with a diamond-like carbon coating layer. This composite structure reduces radio frequency losses (loss tangent < 0.005) while maintaining manufacturability through injection molding for the base material followed by coating processes for the diamond-like layer, thus resolving the contradiction between energy loss reduction and manufacturing ease.
2Power
If transmitting at full power, then communication performance is improved, but local heating occurs causing user discomfort
Solution Approach 1:
The patent changes the material parameters of the cover, specifically using a low-loss thermoplastic material with loss tangent less than 0.005 and applying a diamond-like carbon coating. This parameter change reduces RF energy dissipation as heat, allowing full power transmission while minimizing local heating and user discomfort.
3Reliability
If cover material is optimized for low RF losses, then antenna efficiency is improved, but mechanical strength and durability may be compromised
Solution Approach 1:
The patent uses composite materials where a low-loss thermoplastic material provides the mechanical strength and structural integrity, while a diamond-like carbon coating layer provides the low RF loss properties. This composite approach allows the bulk material to maintain mechanical strength while the coating optimizes antenna efficiency by reducing RF losses.
Solution Approach 2:
The patent applies local quality by using a thin diamond-like carbon coating layer on the outer surface where RF loss reduction is most critical, while the bulk thermoplastic material maintains mechanical strength. This localized application of different material properties optimizes antenna efficiency without compromising overall structural integrity.
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 significantly improves antenna efficiency by reducing radio frequency losses and distributes heat effectively, minimizing the likelihood of user-perceived hot spots and enhancing the device's reliability and user experience.
Implementation Method 1
The material used for an injection molded outer cover must naturally have properties that are advantageous in the process. Also, the completed outer cover must have sufficient mechanical stiffness and durability as well as dimensional accuracy, and it must serve as a good basis for surface treatments such as decorative painting.
Data Source
AI summary
A portable radio device is shown with an outer cover (202) and a radiating antenna element (206, 207, 208, 226, 227) inside the outer cover (202). At a location corresponding to the location of the radiating antenna element (206, 207, 208, 226, 227), there is thermoplastic material (203, 215, 217, 219) the loss tangent value of which is less than 0.005. The outer cover (202) has, on the outer surface thereof and at a location corresponding to the location of the radiating antenna element (206, 207, 208, 226, 227), a coating (204, 209, 216, 218, 220) that is one of: diamond coating, diamond-like coating, diamond-based nanocomposite coating.