Main types of microwave antennas and their uses

　　Main types of microwave antennas and their uses

　　In communication systems, microwave antennas are key devices for microwave transmission. They are used to broadcast microwave signals between at least two points and are an indispensable part of the microwave communication field. Different types of microwave antennas have unique structures and performances, which can meet diverse mechanical and electrical requirements and adapt to different environments and systems. The following is a detailed introduction to the main types of microwave antennas and their uses:

　　1. Microstrip patch antenna

　　The structure of the microstrip patch antenna is relatively unique. It has a patch for transmitting signals. One side of the patch is connected to the ground plane and the other side is connected to the dielectric substrate. In terms of materials, this type of antenna usually contains precious metals such as gold and copper. Its operating frequency range is wide, covering 100MHz to 100GHz.

　　Due to its significant advantages such as low manufacturing cost, small size and light weight, the microstrip patch antenna can be mass-produced. Based on these characteristics, it has applications in many scenarios, such as mobile communication equipment, satellite communication terminals, and IoT sensors. It can meet the needs of equipment for miniaturized and low-cost antennas.

　　2. Horn antenna

　　Horn antenna, also often called microwave horn, is composed of a waveguide with a raised end baffle, and its overall appearance is similar to an amplifier. This antenna is widely used in microwave frequencies above 300MHz and ultra-high frequency bands.

　　Horn antennas have various uses, one of which is to measure the gain of other antennas. It is a common device in the field of antenna testing. In addition, it is also used as a transmitting and receiving antenna for equipment such as microwave radiometers and automatic door locks, playing an important role in scientific research and daily life.

　　3. Reflective antenna

　　Reflective antennas work using reflective reflectors, and their reflective surface is curved to receive radio waves. Because of its dish-like shape, it is also called a reflective dish antenna or dish antenna. This antenna has strong directivity, which is one of its major advantages.

　　With good gain characteristics, reflective antennas have a wide range of application scenarios. In radio telescopes, it can help capture weak radio signals from distant celestial bodies; in high-energy point communications, it can achieve long-distance, high-quality signal transmission; at the same time, it can also be used as a radar to transmit limited radio frequency waves to aircraft, ships and other equipment to ensure the communication and detection needs of these equipment.

　　4. Plasma antenna

　　Unlike traditional antennas that use metal elements as conductive devices, plasma antennas use plasma (ionized gas) for conduction. In the process of receiving or transmitting signals, the gas is ionized to achieve the conduction function. Its operating frequency range can be up to 90GHz.

　　Plasma antennas can be used for receiving and transmitting radio signals. In some fields with high requirements for antenna performance, such as military communications, aerospace communications, etc., it has potential application value and can meet the signal transmission needs in complex environments.

　　5. Multiple-input multiple-output (MIMO) antenna

　　MIMO is the abbreviation of multiple-input multiple-output. This antenna is mainly used in the radio field. It is installed at the receiving and transmitting nodes, and improves the communication rate through multi-antenna collaboration. It is one of the more advanced technologies in the field of smart antennas.

　　In MIMO technology, there are two ways to use multiple antennas. One is to achieve highly effective antenna directivity, which helps improve signal transmission quality and anti-interference ability. MIMO antennas have been widely used in mobile communication systems such as 4G and 5G, significantly improving network capacity and data transmission rate, and meeting people's demand for high-speed communication.

　　6. Omnidirectional antenna

　　Omnidirectional antennas are consistent when receiving and transmitting energy, and can achieve 360-degree signal coverage in the horizontal direction. They are ideal for applications that require good coverage. In some special applications, close-range signal coverage can be achieved by setting a specific downtilt angle for the antenna.

　　Omnidirectional antennas are commonly used in scenarios such as mobile communication base stations and wireless local area network (WLAN) access points. They can provide stable signal connections for multiple users or devices within a certain range to ensure smooth communication.

　　7. Tracking antennas

　　Tracking antennas are designed for automatic balancing and tracking targets. They can still maintain good directivity in harsh environments to ensure continuous signal tracking of moving targets.

　　It has important applications in the aerospace field. For example, it is used to track moving targets such as satellites and aircraft to ensure the stability of communication links with these targets. It can also play a role in radar systems to achieve accurate detection and tracking of moving targets.