Portable Communication Device Antenna Key Impedance

Solution Overview

Problem

Existing portable communication devices for vehicle keyless entry systems face a challenge in maintaining communication efficiency due to size reduction, as the mechanical key compromises antenna performance.

Innovation Solution

A portable communication device with a loop antenna that electrically connects to a metal key, allowing the key to function as an additional antenna, and includes a detection unit and correction unit to adjust impedance and directivity based on the key's storage state, effectively increasing the antenna's virtual size and improving communication efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the portable communication device size is reduced, then the device becomes more portable and compact, but the antenna size must also be reduced which degrades communication efficiency

Engineering Contradiction:

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent merges the mechanical key with the antenna system by electrically connecting the key to the antenna. The key, made of conductive material, becomes an extension of the antenna, effectively increasing the antenna's electrical size without increasing the physical device volume. This combination allows the compact device to maintain communication efficiency comparable to larger devices.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The mechanical key serves dual functions: it acts as both a mechanical tool for door unlocking and as an electrical extension of the antenna for wireless communication. This multi-functionality eliminates the need for a separate antenna component, allowing the device to maintain communication efficiency while minimizing overall size.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Length of moving object

If the antenna size is reduced to accommodate smaller device size, then device portability improves, but communication efficiency and signal transmission quality deteriorate

Engineering Contradiction:

Core Design Contradiction:

Length of moving objectVSProductivity

Solution Approach 1:

The patent extends the antenna functionality into a new dimension by using the mechanical key as an external conductive element. Instead of increasing the antenna size within the device housing, the solution projects the antenna's electrical length outward through the connected key, effectively increasing the radiating structure's dimensions without increasing device volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If a mechanical key is included in the portable communication device, then backup mechanical access is provided, but the conductive key material interferes with antenna performance when not properly managed

Engineering Contradiction:

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent converts the potentially harmful effect of the conductive key (which could interfere with antenna performance) into a beneficial effect. By intentionally electrically connecting the key to the antenna, the key's conductivity becomes advantageous, extending the antenna's effective length and improving communication efficiency, particularly for lower frequency signals.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 configuration enhances communication efficiency by virtually increasing the antenna size, mitigating the degradation caused by device size reduction and ensuring reliable wireless communication.

Implementation Method 1

an antenna that transmits or receives a wireless signal

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

a key that is made of an electrical conductor and mechanically locks or unlocks the door of the vehicle, and a connection unit that electrically connects the antenna and the key

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

the antenna is a loop antenna for wireless signal transmission

Methodology Applied

Scientific EffectMagnetic field generation: Magnetic Field

Data Source

PatentUS9973227B2Portable communication device

Publication Date: 2018.05.15

AI summary

A portable communication device that can suppress degradation in communication efficiency caused by a reduction in device size. The portable communication device includes a mechanical key that is made of an electrical conductor and is for mechanically locking or unlocking a door of a vehicle, and a transmission antenna for transmitting a wireless signal. A storing portion that stores the mechanical key is provided in a case in which the transmission antenna is provided. When the mechanical key is stored in the storing portion, the transmission antenna is electrically connected to the mechanical key. In the portable communication device, the storage state of the mechanical key in the storing portion is detected by a push switch, and impedance correction in a communication circuit is performed by an impedance matching circuit in accordance with the detection result.