How to watch live TV?

The circuits in the TV set demodulate the video and audio signals from the microwave signals, which are played by the display and speakers respectively, so that we can watch the Olympic Games broadcast without leaving home.

At the beginning of the Olympic Games, people who love sports are willing to stay up late to watch the live broadcast of sports games, because the live broadcast and replay of sports games bring people completely different experiences. Why can TV broadcast the game at the game site thousands of miles away? This is due to the live TV technology.

Generally speaking, a TV live broadcast system includes signal acquisition, processing, transmission, reception and restoration. The task of collecting images and sound signals is completed by the camera. A camera is a device that converts optical images and sounds into electrical signals. It captures the real-time optical image of the game scene through the lens, and then outputs the electrical signal that meets the transmission standard through its internal photoelectric conversion system and video processing circuit. At the same time, the sound signal is also converted into another electrical signal through the microphone for output. Subsequently, the video and audio signals output by the camera will be transmitted to TV stations or TV relay vehicles, and then loaded onto microwave signals by the system after corresponding signal processing. This microwave signal is transmitted to the transmission tower by cable, and then transmitted to all directions by antenna. Because microwaves travel at the speed of light, it is almost instantaneous that microwave signals travel hundreds of kilometers, so there is almost no delay in the microwave signals received by our TV sets.

The circuits in the TV set demodulate the video and audio signals from the microwave signals, which are played by the display and speakers respectively, so that we can watch the Olympic Games broadcast without leaving home.

The technology of live TV broadcast is constantly improving. For example, in the signal transmission link, because the coverage of the traditional way of transmitting signals through TV towers is very limited, and the signals are greatly affected by the weather, satellite relay transmission and optical cable transmission are more and more widely used to transmit signals to the ground receiving center in the city, and then the signals are processed by the center and transmitted to thousands of households through cables. The advantages of this method are long transmission distance and high signal quality.