The core components of the field monitoring radar antenna include five modules: radiation unit, beamforming network, antenna cover, mechanical support and drive system, and RF interface component. Each module works together to achieve the transmission and reception of electromagnetic waves and beam pointing control.
1, Radiation unit
1. It is the core component of the antenna to achieve bidirectional conversion between RF signals and free space electromagnetic waves. Field monitoring radar commonly uses two types: microstrip patch units and oscillator units;
2. Microstrip patch units are commonly used in S-band and X-band field monitoring radars, with small size and high integration, suitable for large-scale array layout; The oscillator unit is commonly used in the L-band, with high radiation efficiency, strong anti occlusion ability, and is suitable for long-distance field monitoring and detection;
3. The radiation units arranged in an array achieve beam scanning through phase control, covering the designated monitoring airspace.
2, Beamforming network
1. Used for distributing and synthesizing RF signals, and accurately controlling the phase and amplitude of each radiating unit to achieve beamforming and directional scanning;
2. Active phased array field monitoring radars often use beam networks with integrated T/R components, which directly complete signal amplification, phase adjustment, and power distribution at the unit level;
3. Mechanical scanning field monitoring radars often use passive beam networks, consisting of power dividers, phase shifters, and attenuators, to achieve uniform distribution and phase adjustment of RF signals.
3, Antenna cover
1. Used to protect internal radiation units and structural components from outdoor environmental erosion, while minimizing losses in electromagnetic wave transmission;
2. The mainstream transparent materials are fiberglass and polytetrafluoroethylene composite materials, which need to be matched with the working band of the field monitoring radar. The transmittance should be higher than 90% to ensure the quality of signal transmission;
3. The antenna cover deployed outdoors will be additionally sprayed with a protective coating that is resistant to ultraviolet radiation and wind and rain corrosion, extending its service life.
4, Mechanical support and drive system
1. The core motion module of mechanical scanning field monitoring radar includes azimuth/elevation rotating bracket, servo drive motor, and precision reduction mechanism;
2. The bracket is often made of aluminum alloy or low-alloy steel structure to ensure the structural rigidity and stability of the antenna during full space scanning;
3. The servo system achieves beam pointing accuracy through closed-loop control, and the azimuth scanning rate of conventional field monitoring radar is not less than 12 revolutions per minute, meeting the refresh rate requirements of real-time field monitoring.
5, RF interface component
1. Used to connect antennas and radar receivers/transmitters, including RF transmission cables, RF connectors, and lightning protection modules;
2. It is necessary to meet the requirements of high-power RF signal transmission, and the system standing wave ratio should be less than 1.2 to reduce signal reflection loss;
3. Outdoor interfaces will be equipped with waterproof and dustproof sealing kits, as well as surge protectors to prevent lightning strikes and electromagnetic interference from damaging the radar system.
