Adcock antenna

Aerial view of five tall antenna towers standing on flat terrain; four are arranged in a square, and the fifth one is at the center
Adcock radio range ground station. Hundreds of these stations were deployed around the U.S. alone.

The Adcock antenna is an antenna array consisting of four equidistant vertical elements which can be used to transmit or receive directional radio waves.

The Adcock array was invented and patented by British engineer Frank Adcock and since his August 1919 British Patent No. 130,490, the 'Adcock Aerial' has been used for a variety of applications, both civilian and military.[1][2][3] Although originally conceived for receiving low frequency (LF) waves, it has also been used for transmitting, and has since been adapted for use at much higher frequencies, up to ultra high frequency (UHF).[4][5]

In the early 1930s, the Adcock antenna (transmitting in the LF/MF bands) became a key feature of the newly created radio navigation system for aviation. The low frequency radio range (LFR) network, which consisted of hundreds of Adcock antenna arrays, defined the airways used by aircraft for instrument flying. The LFR remained as the main aerial navigation technology until it was replaced by the VOR system in the 1950s and 1960s.

The Adcock antenna array has been widely used commercially, and implemented in vertical antenna heights ranging from over 40 m (130 feet) in the LFR network, to as small as 13 cm (5 inches) in tactical direction finding applications (receiving in the UHF band).[5][6](pp 88–89)

  1. ^ GB 130490, Frank Adcock, "Improvements in Means for Determining the Direction of a Distant Source of Electro-magnetic Radiation", published 1919-08-07, issued 1919-08-07  (Note: The patent lawyer's name appears as inventor, with "F. Adcock" in parentheses, since Lt. Adcock, Royal Engineers(RE) Service Number 33962 was serving in wartime France at the time.)
  2. ^ "Quadrupole Adcock direction finder and antenna therefor". USPTO. 17 February 1976. U.S. Patent 3939477 – via freepatents.com.
  3. ^ Beauchamp, K. G. (2001). History of telegraphy. IET. p. 367. ISBN 0-85296-792-6.
  4. ^ "Adcock DF antenna 20–1000 MHz" (PDF). Poynting Antennas (poynting.co.za). Retrieved 2009-07-29.[dead link‍]
  5. ^ a b "MA1410 mobile direction finding antenna" (PDF). Cubic Defense Applications (cubic.com). Archived from the original (PDF) on 2010-08-27. Retrieved 2009-07-29.
  6. ^ Johnson, Randy (2003). "Part III: Emerging technologies the radio-range – the radio beacon and visual indicator" (PDF). Journal of Air Transportation. Blind flying on the beam: Aeronautical communication, navigation and surveillance: Its origins and the politics of technology. 8 (2): 79–102, esp. pp 88–89. Archived from the original (PDF) on 29 October 2008. Retrieved 16 May 2023.