Wideband Circular Polarized Antenna for Radar Detection Applications

Wideband Circularly Polarized Antennas: A "Full-Scene Perception Tool" for Radar Detection
From the "clairvoyant" of national defense and air defense to the "super-ears" of weather warning, from the "safety barrier" of shipborne navigation to the "intelligent sentinel" of vehicular traffic, radar detection systems have become core sensing devices in many fields of modern society. Antennas, as the "signal transmission and reception hub" of radar, directly determine the range, accuracy, and anti-interference capabilities of target detection. Wideband circularly polarized antennas are a key technology designed to address the challenges of radar's multi-target coverage, interference rejection in complex environments, and high-precision identification.

Core Advantages: Addressing the Three Core Requirements of Radar Detection

1. Ultra-Wideband Coverage, Enabling "One Antenna, Multiple Targets" Detection

Traditional radar antennas are often limited to narrow frequency bands, requiring multiple antennas to cover the detection frequency bands of different targets (such as low-altitude aircraft, ships, and cloud cover). This not only increases system size and cost but also easily leads to signal discontinuities. The broadband circularly polarized antenna achieves ultra-wide coverage across the L to Ku band (1-18 GHz) through innovative radiating element design and impedance matching technology, with a relative bandwidth exceeding 30%. Whether it's ground-based air defense radars simultaneously detecting low-altitude, slow-moving targets (such as drones) and high-altitude, high-speed targets (such as fighter jets), or weather radars monitoring clouds and precipitation particles at different altitudes, antenna replacement is unnecessary, significantly enhancing the radar system's multi-mission adaptability. 2. Circular Polarization Anti-interference, Breaking Through "Detection Blind Spots" in Complex Environments
Radar detection often faces complex environments such as cloud clutter, ground reflections, and electronic interference. Traditional linearly polarized antennas are susceptible to polarization mismatch, resulting in signal attenuation and targets being "buried" in the clutter. However, wideband circularly polarized antennas, through their rotating electric field characteristics, achieve bidirectional anti-interference:

Natural Interference: Effectively cancels clutter signals in weather conditions such as cloud, rain, fog, and snow, reducing weather radar detection errors in precipitation intensity and cloud thickness by over 20%;

Anti-Interference: Resists polarization interference from enemy electronic warfare equipment, ensuring that air defense radars maintain a target detection probability of over 90% in complex electromagnetic environments;

Multipath Interference: Reduces the impact of ground and sea reflections on signals, enabling shipborne navigation radars to accurately identify small ships within 5 kilometers in complex near-shore terrain. 3. High Polarization Purity + Stable Pattern Ensures "High-Precision Identification"

The radar's precise target positioning (range, azimuth, altitude) and contour recognition rely on the antenna's polarization purity and pattern stability:

The broadband circularly polarized antenna has a polarization purity (axial ratio) of ≤3dB, maintaining stable circular polarization characteristics across the entire broadband range. This allows for clear differentiation of target polarization scattering characteristics (e.g., metallic and non-metallic targets), enabling the radar to achieve "precise target identification."

Through optimized array layout and feed network, the antenna's pattern distortion across the broadband is ≤5%, and its sidelobe level is ≤-25dB. This effectively suppresses sidelobe interference, enabling ground-based fire control radars to maintain a positioning error of less than 10 meters for targets within 100 kilometers. Typical Applications: Enabling Multi-Domain Radar System Upgrades
In ground-based air defense radars, the wideband circularly polarized antenna, with its wideband coverage, meets multi-target detection requirements. Combined with circular polarization's anti-interference capabilities, it ensures continuous tracking of low- and high-altitude targets, building a strong "perception defense" for air defense early warning. For shipborne navigation radars, it effectively resists sea clutter and near-shore multipath interference, accurately identifying small ships and buoys within 5 kilometers, significantly improving navigation safety. For airborne fire control radars, the antenna features a lightweight design (weighing ≤ 2kg) for flexible adaptation to aircraft payloads. Its wideband and high gain advantages enable beyond-visual-range target detection. For weather radars, its wideband coverage enables monitoring of meteorological targets at varying altitudes, while its cloud and rain clutter resistance significantly improves the accuracy of early warnings for disasters such as precipitation and typhoons. For vehicle-mounted traffic radars, its narrow beam design combined with circular polarization's anti-interference capabilities enables precise ranging (≤ 0.5 meter) of vehicles and pedestrians ahead, providing reliable perception support for autonomous driving. Customization Capabilities: Adapting to the Diverse Needs of Radar Platforms

Based on the environmental characteristics and installation requirements of different radar platforms, the wideband circularly polarized antenna offers full-scenario customization:

Structural Customization: Supports flat-panel (thickness ≤ 50mm, suitable for airborne/vehicle-mounted platforms), array (expandable up to 128 elements for increased detection range), and conformal design (adaptable to shipborne radomes and ground-based radar antenna arrays).

Environmental Adaptability: Integrated high and low temperature compensation modules (-55°C to 125°C), vibration resistance (10-2000Hz), and corrosion resistance (salt spray level ≥ 96 hours) ensure long-term stable operation in harsh environments at sea, on land, and in the air.

System Integration: Seamlessly integrates with radar signal processing units and data acquisition modules, providing an integrated "antenna + signal processing" solution and shortening radar system R&D cycles.

From national defense security, where the enemy is kept thousands of miles away, to public welfare applications such as disaster warning and intelligent transportation, the wideband circularly polarized antenna, with its core advantages of "full-band coverage, strong anti-interference, and high-precision detection," has become the "core engine" for radar system upgrades. In the future, as radar technology develops toward "multifunctional integration and intelligent perception," this antenna will further break through the frequency band limit (expanding to the Ka band) and improve integration, building a "more sensitive and reliable perception network" for multi-domain radar detection.