Compact Dual-Band GNSS Antenna with Planar Loop for LHCP Suppression
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Solution Overview
Problem
Existing GNSS antenna systems face reduced positioning accuracy due to the reception of reflected satellite signals, particularly left-hand circularly polarized (LHCP) signals in the rear hemisphere, and require reduced dimensions and weight while maintaining efficient operation across multiple frequency bands.
Innovation Solution
A dual-band antenna system incorporating a Microstrip Patch (MP) radiator with a horizontally disposed loop radiator and a passive MP radiator, where the loop radiator is excited to provide anti-phase excitation of LHCP waves in the rear hemisphere, reducing the directional diagram level and antenna dimensions through field interference and dielectric or impedance structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an additional antenna is used to reduce radiation level in the rear hemisphere, then LHCP field suppression is improved, but antenna vertical dimension increases
Solution Approach 1:
The patent transitions from a vertical stacking arrangement to a planar configuration where the loop radiator is positioned in the same plane as the patch radiator. This dimensional change allows LHCP suppression without increasing vertical dimension, as the loop radiator extends horizontally rather than vertically.
Solution Approach 2:
The patent divides the antenna system into two functionally distinct radiators: a patch radiator for primary radiation and a loop radiator for LHCP suppression. This segmentation allows each component to be optimized for its specific function while maintaining a compact overall structure.
2Weight of stationary object
If antenna dimensions are reduced, then weight is decreased, but maintaining effective LHCP suppression becomes difficult
Solution Approach 1:
By positioning the loop radiator in the same plane as the patch radiator rather than stacking it vertically, the patent achieves LHCP suppression in a compact footprint. This planar arrangement reduces both vertical and horizontal dimensions compared to traditional stacked configurations.
Solution Approach 2:
The patent combines the radiation function and LHCP suppression function into a single integrated planar structure. The patch and loop radiators work together in the same plane, eliminating the need for separate vertical stacks and reducing overall antenna dimensions and weight.
3Adaptability or versatility
If dual-band operation is implemented, then frequency versatility is improved, but antenna structural complexity increases
Solution Approach 1:
The patent designs the patch and loop radiators to operate effectively across both L1 and L5 frequency bands. The same structural configuration provides dual-band functionality without requiring separate antenna structures for each frequency, thereby reducing overall complexity.
Solution Approach 2:
The patent merges the dual-band operation capability into a single integrated planar structure. Both frequency bands are supported by the same patch-loop radiator configuration, eliminating the need for multiple separate antenna systems and reducing structural complexity.
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 proposed antenna design effectively suppresses LHCP fields in a wide angle sector of the rear hemisphere, enhances the operation of the passive high-frequency radiator, and reduces overall antenna dimensions, improving multipath reception and bandwidth efficiency.
Implementation Method 1
the loop radiator is excited to provide anti-phase excitation of LHCP waves in the rear hemisphere, reducing the directional diagram level and antenna dimensions through field interference
Data Source
AI summary
A compact GNSS antenna system reduces directional diagram level in the rear hemisphere primarily for LHCP component. It can be used for reducing multipath reception. A dual-band antenna system for receiving radio signals includes an active Microstrip Patch (MP) High Frequency (HF) circularly-polarized radiator disposed directly on a radiating patch of an active MP low-frequency (LF) radiator. The radiating patch of the active MP LF radiator serves as a ground plane of the MP HF radiator. A loop HF radiator is coaxially arranged around the ground plane of the MP HF radiator. A passive LF radiator is under the ground plane of the active MP LF radiator. A loop LF radiator is axially located around the ground plane of the active MP LF radiator. The loop HF radiator and the loop LF radiator are each excited by a transmission line and a power circuit to generate RHCP waves.