What Is an Antenna Aperture?
In fighter aircraft, the antenna aperture of the RF sensor is a device used to radiate and receive radio waves.
- In fighter aircraft, the antenna aperture of the RF sensor is used to radiate and receive
- By function, the antenna aperture of RF sensors mainly includes radio frequency antennas and aperture electronics. On advanced fighter aircrafts, these antennas and aperture electronics often have a wide operating frequency band due to multi-task and multi-function requirements, and have the ability to propagate different waveforms. Electromagnetic wave capability: can also be used in different mission states (including
- Compared to ships and ground air defense systems, fighter aircraft have limited space, but they have many RF sensor antennas, wide frequency coverage, high sensitivity reception and high power transmission, and stealth of antenna apertures on advanced fighter aircraft. Requirements, so in order to ensure that all equipment can work properly, how to select and position the antenna is very important.
- Generally, the configuration plan of each antenna should be correctly estimated at the beginning of the aircraft design, and a comprehensive trade-off should be made in terms of antenna gain distribution, energy distribution in the near area of the antenna, isolation of the transmitting and receiving antennas, and mutual coupling between antennas. The joint design is carried out among professionals. The antenna frequency band of the RF sensor is very wide, which can be from VHF / UHF to millimeter waves. Therefore, the antenna layout design should be based on the operating frequency of each subsystem and its equipment, and the aircraft geometry (if it is invisible) The aircraft also needs to consider the stealth index requirements) to determine the corresponding design method. Generally there are low frequency method, resonance method and high frequency method.
- However, on the advanced fighter jets represented by the F-22 and F-35 aircraft, because of the stealth requirements, there is a special design for the layout of the antenna aperture. Its most important work is to reduce the number of apertures by using the integrated design of the radio frequency aperture as much as possible to achieve the purpose of reducing the radar cross-sectional area (RCS) scattering of the airborne radio frequency aperture system: F-35 aircraft's airborne communication / electronic warfare ( CNI / EW) antenna aperture design is taken as an example. Since it needs airspace coverage with omnidirectional field of view space to meet the omnidirectional perception of the environment, a complex aerodynamic model system is established by the special aerodynamic shape of the aircraft. The layout of the comprehensive antenna aperture has been comprehensively predicted, evaluated, and optimized from the aspects of antenna pattern, antenna efficiency, receive and / or transmit gain, sidelobe level, input impedance, center frequency, antenna bandwidth, and polarization characteristics. An ideal comprehensive antenna aperture layout and installation scheme that meets both the electrical performance and the stealth index is developed. [1]