Multi-Loop RF Antenna for Induction Hob Communication
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Solution Overview
Problem
Existing induction heating systems with peripheral-mounted RF transponders face communication loss when objects are rotated or displaced, limiting user freedom in positioning cookware due to restricted RF communication zones.
Innovation Solution
A multi-loop RF antenna assembly surrounding the heating hob, with each loop having an inner section defining an enclosed communication region, creating a continuous communication zone that maintains connectivity regardless of the object's position, including a substrate-mounted antenna configuration with overlapped loops and tuned circuitry for high signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single RF antenna is used at the center of the cooking hob, then RFID communication can be maintained with objects rotated 360 degrees, but the object cannot be heated to temperatures exceeding the RFID tag's maximum operating temperature range
Solution Approach 1:
The single central antenna is divided into multiple antenna loops arranged around the periphery of the cooking hob. Each loop is positioned to cover a specific angular sector, collectively providing 360-degree coverage while allowing the RFID tag to be placed in a cooler peripheral location on the object being heated.
2Temperature
If the RFID tag is mounted on the periphery of the object to reduce heat load, then the tag can operate at lower temperatures, but RF communication is lost when the object is rotated beyond a limited angular range
Solution Approach 1:
Multiple antenna loops are combined to form a collective RF communication zone that surrounds the entire cooking hob. This merged antenna system provides continuous RF coverage for all angular positions, enabling the RFID tag to maintain communication regardless of the object's rotation while remaining mounted in a cool peripheral location.
3Device complexity
If the RFID reader antenna covers only a quadrant of the periphery of the work coil, then the antenna structure is simplified, but the vessel must be maintained in a relatively small range of angular positions
Solution Approach 1:
The antenna system transitions from a two-dimensional planar quadrant layout to a multi-dimensional arrangement with antenna loops positioned at multiple locations around the hob's periphery. This spatial distribution creates overlapping RF fields that collectively cover all angular positions, providing full rotation freedom while maintaining manageable antenna complexity.
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
Enables continuous RF communication over 360° rotation and radial displacement of objects with peripheral-mounted transponders, enhancing user flexibility and reducing communication errors.
Implementation Method 1
RF antenna assemblies... establish and maintain RF communication between the heating apparatus and an object being heated having a peripheral-mounted RF transponder
Implementation Method 2
induction heating systems... use RF communications between a transmitter/receiver forming a part of the induction heater
Data Source
AI summary
An improved antenna assembly (66) designed to maintain RF communication between an object (22, 64, 148) to be heated, and a heating assembly (20, 60) such as an induction heater having a hob (34) equipped with an induction work coil (36). The antenna assembly (66) provides substantially continuous RF communication about the entirety of the hob (34), so that the object (22, 64, 148) can be rotated through substantially 360° , or displaced radially, without loss of RF communication. The preferred antenna assembly (66) includes an antenna (67) mounted upon a substrate (68) and presenting a plurality of continuous, conductive antenna loops (70, 72) oriented to cooperatively and substantially surround the hob (34).