Radio wave interference is a phenomenon that occurs when unwanted signals disrupt the transmission or reception of radio waves. Radio waves are used for a wide range of purposes, from communication to navigation, and any interference can have serious consequences. There are various sources of interference, both natural and human-made.

Natural sources of interference include lightning, solar flares, and the ionosphere. Lightning can produce intense electromagnetic fields that can interfere with radio signals. Solar flares, on the other hand, release large amounts of charged particles that can disrupt the ionosphere, which can in turn affect radio signals. The ionosphere is a layer of the Earth's atmosphere that reflects radio waves back to the ground, and any changes to its properties can cause interference.

In recent years, there has been a significant increase in the number of unmanned aerial vehicles, commonly known as drones. These devices have revolutionized many industries, from filmmaking to agriculture. However, their widespread use has also led to security concerns, particularly when drones are flown in restricted areas, such as airports, military installations, or sensitive facilities. To address this challenge, radars have emerged as a critical tool for detecting, tracking, and mitigating rogue drones.

A radar (Radio Detection and Ranging) system is a device that uses radio waves to detect and locate objects in its vicinity. It sends out a signal that bounces off an object and returns to the radar, providing information about the object's distance, speed, and direction. Radars have been used for decades in various applications, including weather forecasting, air traffic control, and military surveillance.

With the rise of drones, radars have become an essential tool for detecting and tracking these small, fast-moving objects. Drones can be challenging to detect using traditional radar systems because they are relatively small and have low radar cross-sections (RCS). RCS is a measure of how much energy a target reflects back to a radar. Drones have low RCS because they are made of lightweight materials such as plastic or carbon fiber, which absorb rather than reflect radar signals.

Standing Wave Ratio (SWR) is a measurement that quantifies the efficiency of an antenna system. It is an important parameter used in the design, construction, and operation of radio communication systems. SWR is defined as the ratio of the maximum voltage to the minimum voltage on a transmission line. It is a measure of how well the impedance of the antenna system matches the impedance of the transmission line, and is an indicator of how much energy is being reflected back from the antenna system. In general, a lower SWR indicates a better match between the antenna system and the transmission line, and a more efficient transfer of energy from the transmitter to the antenna.