A tower array is an arrangement of multiple radio tower

Radio masts and towers

Radio masts and towers are, typically, tall structures designed to support antennas for telecommunications and broadcasting, including television. They are among the tallest man-made structures...

s which are mast radiator

Mast radiator

A mast radiator is a radio mast or tower in which the whole structure itself functions as an antenna. This design is commonly used for transmitting antennas operating at low frequencies, in the VLF, LF and MF ranges, in particular those used for AM broadcasting. The metal mast is electrically...

s in a phased array

Phased array

In wave theory, a phased array is an array of antennas in which the relative phases of the respective signals feeding the antennas are varied in such a way that the effective radiation pattern of the array is reinforced in a desired direction and suppressed in undesired directions.An antenna array...

. Tower arrays can consist of free-standing or guyed towers or a mix of them.
Tower arrays are used to constitute a 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....

 of a mediumwave

Mediumwave

Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting. For Europe the MW band ranges from 526.5 kHz to 1606.5 kHz...

 or longwave

Longwave

In radio, longwave refers to parts of radio spectrum with relatively long wavelengths. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths...

 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...

.

The number of towers in a tower array can vary.
In many arrays all towers have the same height, but there are also arrays of towers of different height.
The arrangement can vary. For directional antennas with fixed radiation pattern

Radiation pattern

In the field of antenna design the term radiation pattern most commonly refers to the directional dependence of the strength of the radio waves from the antenna or other source ....

, linear arrangements are preferred, while for switchable directional patterns (usually for daytime groundwave versus nighttime skywave

Skywave

Skywave is the propagation of electromagnetic waves bent back to the Earth's surface by the ionosphere. As a result of skywave propagation, a broadcast signal from a distant AM broadcasting station at night, or from a shortwave radio station can sometimes be heard as clearly as local...

), square arrangements are chosen.

Tower arrays with guyed masts

• Longwave transmitter Europe 1
  Longwave transmitter Europe 1
  The Longwave transmitter Europe 1 is the oldest privately owned radio station in Germany, situated at Felsberg-Berus, Germany. It transmits with a power of 2000 kilowatts a French speaking programme, Europe 1 toward France...
  
  
• Transmitter Weisskirchen
  Transmitter Weisskirchen
  The transmitter Weißkirchen is a medium wave broadcasting facility located near Weißkirchen, Oberursel, Germany. It is the most powerful European AM transmitter of the American Forces Network and transmits on 873 kHz with a power of 150 kilowatts...
  
  
• Beidweiler Longwave Transmitter
  Beidweiler longwave transmitter
  The Beidweiler Longwave Transmitter is a high-power broadcasting transmitter for the French-speaking programme of RTL radio on the longwave frequency 234 kHz...
  
  
• Transmitter Wachenbrunn
• Transmitter Ismaning
  Transmitter Ismaning
  The Transmitter Ismaning was a large radio station inaugurated in 1932. From 1932 to 1934 this transmitter, which replaced the transmitter in Munich-Stadelheim, used a T-antenna as transmitting antenna, which was hung up two 115-meter-high freestanding wood framework towers...
  
   (VoA-Station)

Tower arrays with free standing towers

• Junglinster Longwave Transmitter
  Junglinster longwave transmitter
  The Junglinster Longwave Transmitter is a longwave broadcasting facility used by RTL near Junglinster, Luxembourg, which went into service in 1932. Its aerial consists of three free-standing steel-framework towers, which are ground fed radiators. These towers formed a directional aerial for the...
  
  
• Orfordness transmitting station

See also

• Twin Towers (disambiguation)
• 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....
  
  
• longwave
  Longwave
  In radio, longwave refers to parts of radio spectrum with relatively long wavelengths. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths...
  
  
• mediumwave
  Mediumwave
  Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting. For Europe the MW band ranges from 526.5 kHz to 1606.5 kHz...
  
  
• directional array
  Directional array
  In broadcast engineering, directional array refers to an antenna array arranged such that the superposition of the electromagnetic waves produce a predictable electromagnetic field...