An overlap zone, in radio frequency engineering

Radio frequency engineering

Radio frequency engineering is the analysis and design of circuits at frequencies where transmission lines are comparable to the wavelength. It includes the study of amplifiers, oscillators, mixers, demodulators and antennas. This is relevant to RFID, broadcasting, radar, wireless computer...

, is a zone in which the signals from two or more radio station

Radio station

Radio broadcasting is a one-way wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both...

s, transmitting at the same frequency, can be received with comparable intensity. Interference

Co-channel interference

Co-channel interference or CCI is crosstalk from two different radio transmitters using the same frequency. There can be several causes of co-channel radio interference; four examples are listed here....

 occurs frequently in such a zone.

In order to avoid this, a receiver with directional antenna

Directional antenna

A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive and reduced interference from unwanted sources....

 is used, which can then be aligned in such a way that it will only receive the signal of one transmitter. Alternatively, the signals could be separated using a demodulator in single sideband mode.

With digital radio

Digital radio

Digital radio has several meanings:1. Today the most common meaning is digital radio broadcasting technologies, such as the digital audio broadcasting system, also known as Eureka 147. In these systems, the analog audio signal is digitized into zeros and ones, compressed using formats such as...

 (Digital Radio Mondiale

Digital Radio Mondiale

Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for AM broadcasting, particularly shortwave...

 and Digital Audio Broadcasting

Digital audio broadcasting

Digital Audio Broadcasting is a digital radio technology for broadcasting radio stations, used in several countries, particularly in Europe. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format....

being two common types), there is no interference in the overlap zone.