Dual-Antenna Switching Layout for Multi-Band Fire Alarm Gain

Solution Overview

Problem

Existing wireless communication terminals in fire alarms face challenges in achieving satisfactory antenna gain due to insufficient electrical length of the ground circuit board, particularly when operating at different frequencies.

Innovation Solution

A wireless communication terminal is designed with a first and second antenna element, where the first antenna element is in an electric power receiving state and the second antenna element is grounded during communication at the first frequency, and vice versa during communication at the second frequency, allowing the second antenna element to function as a ground wire and improve antenna gain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If antenna elements are designed for different frequencies, then wireless communication capability at multiple frequencies is achieved, but the electrical length of ground becomes insufficient and antenna gain deteriorates

Engineering Contradiction:

Improvewireless communication capability at multiple frequenciesVSAvoidantenna gain

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The second antenna element is designed to serve dual functions: acting as an antenna element for second frequency communication and simultaneously functioning as a ground wire for the first antenna element. This multi-functionality resolves the contradiction by providing sufficient ground electrical length for first frequency operation without requiring separate ground structures, thereby maintaining antenna gain while enabling multi-frequency communication capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the function of the second antenna element with the ground wire function for the first antenna element. By combining these two functions into a single structural element, the invention achieves sufficient ground electrical length for first frequency communication while maintaining the antenna element capability for second frequency operation, thus resolving the antenna gain deterioration issue

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If separate ground wires are added for each antenna element, then antenna gain is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveantenna gainVSAvoidnumber of metal wires and assembly steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The second antenna element is designed to serve dual functions: acting as an antenna element for second frequency communication and simultaneously functioning as a ground wire for the first antenna element. This multi-functionality resolves the contradiction by providing sufficient ground electrical length for first frequency operation without requiring separate ground structures, thereby maintaining antenna gain while enabling multi-frequency communication capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the function of the second antenna element with the ground wire function for the first antenna element. By combining these two functions into a single structural element, the invention achieves sufficient ground electrical length for first frequency communication while maintaining the antenna element capability for second frequency operation, thus resolving the antenna gain deterioration issue

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP3716240B1Wireless communication terminal, fire alarm, and management system

Publication Date: 2023.09.27 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

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AI summary

An object of the present disclosure is to improve an antenna gain. A wireless communication terminal is configured to perform wireless communication at a first frequency and a second frequency which are different from each other. The wireless communication terminal includes a first antenna element (2A), a second antenna element (2B), and a wireless circuit. The wireless circuit is configured to perform at least one of transmission or reception of a radio signal via the first antenna element (2A) and the second antenna element (2B). The wireless communication terminal is configured such that when the wireless communication terminal performs the wireless communication at the first frequency, the first antenna element (2A) is in an electric power receiving state and the second antenna element (2B) is in a grounded state. The wireless communication terminal is configured such that when the wireless communication terminal performs the wireless communication at the second frequency, the second antenna element (2B) is in an electric power receiving state and the first antenna element (2A) is in an opened or grounded state.