Compact Dual-Band GNSS Antenna Using Capacitive Loading
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Solution Overview
Problem
Dual-band antennas for global navigation satellite system (GNSS) receivers are costly and larger in size compared to single-band antennas, making them challenging to integrate into new products while maintaining functionality.
Innovation Solution
A compact dual-band antenna design featuring a substrate with conductive patches and strips that are capacitively coupled, allowing for reduced resonant frequency without increasing size, achieved through specific geometric configurations and materials with high dielectric constants, along with tuning features like concave features and offset feed points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dual-band antenna is designed to support two frequency bands, then the positioning accuracy is improved, but the production cost increases
Solution Approach 1:
The patent combines two separate resonant frequencies (L1 and L5 bands) into a single antenna structure. The conductive patch with specific geometric features (concave portions, offset feed) and capacitive coupling between the patch and conductive strip enables the antenna to resonate at both L1 (1575.42 MHz) and L5 (1176.45 MHz) frequencies simultaneously, eliminating the need for separate antennas for each band and reducing production costs
Solution Approach 2:
The patent uses parameter optimization to achieve dual-band operation. By adjusting the dielectric constant of the substrate (εr between 30-70), the dimensions of the conductive patch (length 10-20mm, width 10-20mm), the gap distance (0.1-5mm), and the geometric features (concave portions with specific dimensions), the antenna resonant frequencies are tuned to match the L1 and L5 bands while maintaining a compact size
2Measurement precision
If a dual-band antenna is designed to support two frequency bands, then the positioning accuracy is improved, but the antenna size increases
Solution Approach 1:
The patent transitions from a planar two-dimensional patch antenna to a three-dimensional structure by adding vertical dimension through capacitive coupling. The conductive strip is positioned at a gap distance (0.1-5mm) from the conductive patch, creating a vertical separation that enables additional resonant modes. This 3D configuration allows dual-band operation within a compact footprint, as the vertical spacing provides the necessary electrical length without increasing the horizontal area
3Ease of operation
If the antenna size is reduced for miniaturization, then the integration ease is improved, but the resonant frequency control becomes more difficult
Solution Approach 1:
The patent employs multiple adjustable parameters to control resonant frequencies in the miniaturized antenna. The dielectric constant (εr=30-70), substrate thickness (3-10mm), conductive patch dimensions (20mm×20mm), gap distance (0.1-5mm), and concave portion dimensions provide multiple degrees of freedom for frequency tuning. This parametric design allows precise control of L1 and L5 resonant frequencies even in the compact size, maintaining manufacturing precision through systematic parameter optimization
Solution Approach 2:
The patent incorporates preliminary design features that pre-establish the resonant frequency characteristics. The concave portions are strategically positioned and dimensioned (e.g., first concave portion: 2mm×3mm, second concave portion: 3mm×2mm) to pre-tune the resonant frequencies to the desired L1 and L5 bands. The offset feed position (e.g., 5mm from center) is also predetermined to excite the appropriate resonant modes, reducing the need for post-manufacturing adjustments
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 design achieves dual-band functionality in a smaller form factor, reducing production costs and enabling efficient integration into GNSS receivers while maintaining accurate resonant frequencies.
Implementation Method 1
The first and second conductive strips may be arranged so that, in use, they are capacitively coupled with the conductive patch. Thus, the first and second conductive strips provide capacitive loading for the patch.
Data Source
AI summary
An antenna is provided comprising a substrate formed of a dielectric material. The substrate has an upper surface, a lower surface, and one or more side surfaces connecting the upper surface with the lower surface. The antenna further comprises a conductive patch on the upper surface of the substrate; a first conductive strip on one of the one or more side surfaces; and a second conductive strip on one of the one or more side surfaces. The first and second conductive strips are arranged at opposing sides of the conductive patch. The antenna further comprises a ground plane, wherein the first and second conductive strips are galvanically isolated from the conductive patch and galvanically connected to the ground plane.