Author: Wg Cdr Rajagopal

Radar, stands for Radio Detection and Ranging, is a technology used to detect and track objects in the surrounding environment. It works by emitting radio waves and analysing the signals that bounce back when they encounter objects. Radar consists of two main components: a transmitter and a receiver. The transmitter generates radio waves, which are electromagnetic waves similar to light waves but with much longer wavelengths. Principle of Radar The radar transmitter sends out short bursts of radio waves, often referred to as radar pulses. These pulses are directed into…

There are certain navigational aids which require to transmit their signals only in a particular direction. For example, Instrument Landing System (ILS) need to transmit in the direction of runway only. Directional antennas serve this purpose by focusing radio waves in a particular direction. Elements of a Directional Antenna. If you look at a Radar Antenna, you would see a semicircular cup shaped reflector attached behind the transmitter. These reflectors are called as parasitic elements which help in achieving directivity. Metallic reflectors are 5% longer and placed behind the ariel.…

The importance to antenna in a radio navigation cannot be ignored. Just to remind you, we had seen earlier that the polar diagram of transmission varies depending on the shape of the antenna. We had also seen that the shape of an antenna plays an important role in both transmission and reception of signals. For example, to transmit and receive horizontally polarised waves, we need both the transmitter and receiver antenna to be horizontal. Transmitter and Receiver Ariel There are two types of antenna. The transmitter and the receiver. Transmitter…