Mobile Terminal Antenna Feed Network for Multiband Isolation

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Solution Overview

Problem

Existing antenna designs for mobile terminals face challenges in covering multiple frequency bands efficiently, particularly due to high component loss in the high frequency band caused by frequency division circuits, leading to performance issues and increased space requirements.

Innovation Solution

The antenna apparatus employs a filter matching network with separate feeding parts for low and high frequency signals, eliminating the need for a filter component in the radio frequency circuit, which improves signal stability and reduces loss by using band-stop and band-pass filters to isolate and match signals effectively across different frequency bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a frequency dividing circuit is used to separate intermediate frequency and high frequency bands in a single antenna architecture, then multiband communication is achieved, but component loss greater than 3 dB occurs in the high frequency band

Engineering Contradiction:
Improvemultiband communication capabilityVSAvoidhigh frequency signal loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent divides the antenna system into two independent feeding structures: a first feeding structure for low and intermediate frequency bands, and a second feeding structure for high frequency bands. This segmentation eliminates the need for frequency dividing circuits, thereby reducing signal loss in the high frequency band while maintaining multiband communication capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the high frequency band handling from the first feeding structure and creates a separate second feeding structure dedicated to high frequency bands. This extraction removes the harmful frequency dividing circuit from the high frequency path, eliminating the component loss that previously affected high frequency signal quality.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If different frequency bands are manufactured in different antennas with a single feeding structure, then frequency band coverage is achieved, but a large amount of space is occupied and isolation structures are required

Engineering Contradiction:
Improvefrequency band coverageVSAvoidantenna space occupation
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent creates a unified antenna structure that serves multiple frequency bands through two feeding structures sharing common radiation elements. The first feeding structure handles low and intermediate bands while the second feeding structure handles high bands, allowing a single antenna assembly to perform multiple functions across different frequency ranges without requiring separate antennas for each band.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the handling of multiple frequency bands into a single antenna structure by combining two feeding structures that share common radiation elements and ground systems. This merging reduces the total space required compared to using separate antennas for each frequency band, while still achieving comprehensive frequency band coverage.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the intermediate frequency band (2170 MHz) and high frequency band (2300 MHz) are closely spaced, then spectrum utilization is improved, but frequency division becomes difficult and signal isolation is compromised

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidsignal isolation between bands
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the frequency handling by assigning the first feeding structure to low and intermediate bands and the second feeding structure to high bands. This segmentation provides physical separation of the signal paths, improving isolation between the closely spaced intermediate and high frequency bands while maintaining efficient spectrum utilization.

Inventive Principle:
Principle #1Segmentation

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 ensures stable transmission of intermediate and high frequency signals with reduced loss and improved isolation, enhancing the antenna's performance and efficiency in covering multiple frequency bands while minimizing space and design complexity.

Implementation Method 1

uses band-stop and band-pass filters to isolate and match signals effectively across different frequency bands

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Data Source

PatentEP3767742B1Antenna device and mobile terminal
Publication Date: 2023.11.22 HUAWEI TECH CO LTD
  • EP3767742B1 patent drawingFigure 1
  • EP3767742B1 patent drawingFigure 2
  • EP3767742B1 patent drawingFigure 3~4

AI summary

This application relates to a mobile terminal and an antenna apparatus, including a first feeding part, a second feeding part, a filter matching network, and a radiator. The filter matching network includes a first port, a second port, and a third port. The first feeding part is electrically connected to the first port, the second feeding part is electrically connected to the second port, and the radiator is electrically connected to the third port. The first feeding part is configured to feed a low frequency signal and an intermediate frequency signal, the second feeding part is configured to feed a high frequency signal, a maximum frequency value of the low frequency signal and the intermediate frequency signal is 2170 MHz, a minimum frequency value of the high frequency signal is 2300 MHz, the low frequency signal, the intermediate frequency signal, and the high frequency signal are respectively fed the filter matching network by using the first feeding part and the second feeding part, and the filter matching network is configured to improve isolation between the low frequency signal and the intermediate frequency signal, and the high frequency signal. In this application, stability of a signal at the lowest frequency value of the high frequency signal and the highest frequency value of the low frequency signal and the intermediate frequency signal can be ensured, and a loss of the 2300 MHz signal can be reduced.