Miniature Multi-Frequency Antenna With Inter-Electrode Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional small-sized antennas are susceptible to reactance effects from nearby dielectric materials, leading to resonant frequency deviations and reduced signal efficiency, and typically can only receive signals of a single frequency due to narrow bandwidth, requiring multiple antennas that increase device size.
Innovation Solution
A miniature multi-frequency antenna design featuring a signal electrode with partially overlapping branches forming a capacitive region for lower frequency adjustment and a PIFA design for higher frequency bands, minimizing mutual interference and allowing for size reduction and easy impedance and resonant frequency tuning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional PIFA or Loop Antenna is used in small-sized wireless communication devices, then the antenna construction is simple and cost is low, but the antenna is susceptible to reactance effects from nearby dielectric materials causing resonant frequency deviation and reduced signal efficiency
Solution Approach 1:
The antenna is divided into multiple segments: a PIFA structure for higher frequency bands and a loop structure with capacitive regions for lower frequency bands. Each segment operates semi-independently, allowing the PIFA portion to handle frequencies where it excels while the loop portion with adjustable capacitors handles lower frequencies, reducing mutual interference and improving frequency stability
Solution Approach 2:
Capacitive regions are introduced into the loop structure with adjustable capacitance values. By changing the capacitance parameters in the loop portion, the resonant frequency can be precisely tuned and stabilized against reactance effects from nearby dielectric materials, while maintaining the simple construction advantage
2Reliability
If a Loop Antenna is used to reduce susceptibility to surrounding environment, then the antenna shows less susceptibility to dielectric materials, but it is capable of receiving signals of a single frequency only due to narrow bandwidth
Solution Approach 1:
The patent merges two different antenna structures into one hybrid antenna: the PIFA structure known for good higher frequency performance and the loop structure known for environmental stability. The PIFA portion handles higher frequency bands while the loop portion with adjustable capacitors handles lower frequency bands, achieving multi-frequency capability while maintaining resistance to dielectric reactance effects
Solution Approach 2:
The hybrid antenna structure serves multiple frequency bands through a single unified design. The PIFA portion provides resonance at higher frequencies while the loop portion with variable capacitors provides resonance at lower frequencies, enabling the single antenna to universally cover multiple frequency bands required for modern wireless communication devices
3Adaptability or versatility
If multiple antennas are integrated to receive signals with more than two frequencies, then the frequency band coverage is increased, but the size of the antenna is enlarged
Solution Approach 1:
Instead of using multiple separate antennas, the patent merges the PIFA structure and loop structure into a single hybrid antenna. The PIFA portion and loop portion share the same physical space and are electrically connected, allowing multi-frequency operation from a compact single-antenna structure rather than requiring multiple larger antennas
Solution Approach 2:
The loop structure contains nested capacitive regions within its perimeter, and the PIFA structure is positioned in proximity and electrical connection to the loop. This nested and integrated arrangement allows both antenna types to coexist in a compact form factor, achieving multi-frequency capability without proportionally increasing the overall antenna volume
4Ease of manufacture
If conventional multi-frequency antennas are designed using PIFA or monopole, then the design is straightforward, but significant interaction between different frequency bands occurs making adjustment complex
Solution Approach 1:
The antenna is segmented into functionally distinct portions: the PIFA structure primarily handles higher frequency bands while the loop structure with capacitive regions primarily handles lower frequency bands. This segmentation reduces coupling and interaction between frequency bands, making impedance and frequency adjustment simpler and more predictable for each band independently
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
The antenna achieves stable multi-frequency signal transmission and reception with reduced size and complexity, enabling easier customization and lower fabrication costs, while being suitable for mass production and integration with circuit boards.
Implementation Method 1
The partially overlapped signal electrode and the ground electrode form an inter-electrode region having capacitive effect that will help to significantly reduce the antenna size
Implementation Method 2
a plurality of electrodes partially overlapped each other to form at least one particular region with specific capacitance and to adjust a resonant frequency of the antenna
Data Source
AI summary
A miniature multi-frequency antenna, comprising at least one dielectric substrate, at least one signal electrode and at least one ground electrode. The signal electrode and the ground electrode are disposed on a substrate. The signal electrode contains at least two branches and at least one branch is partially overlapped with the ground electrode. Each interlayer region between the partially overlapped electrodes forms a specific capacitance. By utilizing this interlayer capacitive effect, the resonant frequency of lower frequency band is achieved while the size of the antenna is effectively reduced. For obtaining the resonant frequency of the high frequency bands, the design concept of PIFA is applied on other branches of the signal electrode. A miniature antenna thus obtained is capable of transmitting/receiving multi-frequency signals having the benefits of easily adjusting impedance and resonant frequency.