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2. Random wire antenna - Wikipedia

   en.wikipedia.org/wiki/Random_wire_antenna

   Often random wire antennas are also (inaccurately) referred to as long-wire antennas.There is no accepted minimum size, but actual long-wire antennas must be greater than at least a quarter-wavelength (⁠ 1 / 4 ⁠ λ) or perhaps greater than a half (⁠ 1 / 2 ⁠ λ) at the frequency the long wire antenna is used for, and even a half-wave may only be considered "long-ish" rather than "truly ...

3. Two-wire circuit - Wikipedia

   en.wikipedia.org/wiki/Two-wire_circuit

   Two-wire circuits in new installations are limited to intercom and military field telephone applications, though these too are being supplanted by modern digital communication modes. To communicate in both directions in the same wire pair, conversion between four-wire and two-wire was necessary, both at the telephone and at the central office .

4. Rectenna - Wikipedia

   en.wikipedia.org/wiki/Rectenna

   The invention of the rectenna in the 1960s made long distance wireless power transmission feasible. The rectenna was invented in 1964 and patented in 1969 [2] by US electrical engineer William C. Brown, who demonstrated it with a model helicopter powered by microwaves transmitted from the ground, received by an attached rectenna. [3]

5. Moxon antenna - Wikipedia

   en.wikipedia.org/wiki/Moxon_antenna

   Moxon antenna for the 20-meter band.The antenna is the faint rectangle of wires held in tension by the bent X-shaped support frame. Moxon antenna for the 2-meter band. The Moxon antenna or Moxon rectangle is a simple and mechanically rugged two-element parasitic array, single-frequency antenna. [1]

6. Numerical Electromagnetics Code - Wikipedia

   en.wikipedia.org/wiki/Numerical_Electromagnetics...

   2.4 GHz helical antenna radiation pattern (NEC simulation) The Numerical Electromagnetics Code, or NEC, is a popular antenna modeling computer program for wire and surface antennas. It was originally written in FORTRAN during the 1970s by Gerald Burke and Andrew Poggio of the Lawrence Livermore National Laboratory. The code was made publicly ...

7. Cage aerial - Wikipedia

   en.wikipedia.org/wiki/Cage_aerial

   This antenna achieved transatlantic contacts on 1.5 MHz, at a power of 440 W. A cage antenna ( British cage aerial ) is a radio antenna where a conventional design has been augmented by replacing a single long conductor with several parallel wires, connected at their ends, and held in position by ring spacers or support struts mounted on a ...

8. Counterpoise (ground system) - Wikipedia

   en.wikipedia.org/wiki/Counterpoise_(ground_system)

   Inverted-L antenna with counterpoise, in a powerful amateur radio station, Colorado, 1920. The counterpoise is the lower grid of horizontal wires, suspended below the antenna. The largest use of counterpoises is in transmitters on the low frequency (LF) and very low frequency (VLF) bands, as they are very sensitive to ground resistance. [2]

9. Beverage antenna - Wikipedia

   en.wikipedia.org/wiki/Beverage_antenna

   The Beverage antenna or "wave antenna" is a long-wire receiving antenna mainly used in the low frequency and medium frequency radio bands, invented by Harold H. Beverage in 1921. [1] It is used by amateur radio operators, shortwave listeners, longwave radio DXers and for military applications.