Talk:Whip antenna

Monopole antenna?

I think it could be better to move the theory into "monopole antenna" article (now redirect to "whip antenna"), stress there the differences against the dipole antenna, and keep only the whip-specific issues here. Eg, the FLR-9 antenna has the outer ring consisting of monopoles, and I doubt they are of the flexible whip type. Opinions, comments? --Shaddack 07:08, 10 October 2005 (UTC)

propose merging with "Rubber Ducky Antenna"

Rubber_Ducky_antenna has better content, whip antenna is the better (more formal) name. Bernd in Japan 14:06, 11 March 2007 (UTC)

In the section on Electrically Short Whips the statement "Multi-band operation is possible with coils at about one-half or one-third etc..." is confusing. One-half or one-third of what? --Xmitr2 (talk) 05:08, 5 July 2014 (UTC)

Misleading Description

The page says this:

"For example, the common quarter-wave whip antennas used on FM radios in the USA are approximately 75 cm long, which is roughly one-quarter the length of radio waves in the FM radio band, which are 2.78 to 3.41 meters long. Half-wave antennas are also common."

Radio waves do not have a length as they are dimensionless photons. Wavelength refers to the optimal group motion they induce in a conductive material. The less ability a length of conductor has to produce group motions suitable for the incoming photons, the less it will absorb. — Preceding unsigned comment added by 36.37.205.121 (talk) 06:11, 22 April 2016 (UTC)

I think you may have been misinformed. As with all quantum particles, photons, the quanta of electromagnetic radiation, can be regarded as either particles or waves. In the case of frequencies as low as radio waves, the photons have such low energy that they are virtually undetectible individually; from Planck's equation the energy of a 100 MHz FM radio photon is

$E=h\nu =6.6(10^{-35})\times 100(10^{6})=6.6(10^{-27}){\text{joules}}$

So an antenna radiating radio waves is emitting a huge number of photons per second, about 10²⁸. Therefore, as with other processes involving huge numbers of quanta, the operation of antennas is regarded as a "classical" process, which is described by classical electromagnetism; Maxwell's equations, with no need for quantum mechanics. In electromagnetics, a radio wave is described as a travelling coupled electric and magnetic field. For a radio wave of a single frequency, the fields have the form of sinusoids which are periodic; they repeat after a certain distance. This is called the wavelength. --Chetvorno^TALK 10:22, 22 April 2016 (UTC)

Does any theory address why/how an electromagnetic radio wave is "coupled" to (or "guided" by) the surface of a metallic guide? [I am a chemist who looks at a metal wire and wonders why an EM field (a 'packet' of low-energy radio-frequency photons launched by whatever source) tends to stay on the surface of a wire even when the wire makes a gentle bend around a corner.] ...I know I digress a bit from whip antenna, but my mind won't let me put this question to rest. Geoff9614 (talk) 22:05, 5 April 2024 (UTC)

Yes. I will contact you on your talk page, which I will create. Constant314 (talk) 17:55, 28 April 2024 (UTC)

What types of physical and material properties increase the figure of merit of a conductor for producing "group motions" [on/around the waveguide] for the incoming photons? Is it simply smoothness of surface and electrical conductivity? Or is something else, like a design feature, very important? 158.51.117.14 (talk) 21:40, 5 April 2024 (UTC)

Correction of gain statement

I have deleted the statement that a whip has 3 dB gain over a dipole. I believe this confusion arose from the fact that a quarter wave antenna modelled over a perfect ground shows gain over a dipole in free space. This is a meaningless comparison. A dipole over a perfect ground will have 3 dB additional gain since all of the energy is confined to the upper hemisphere. In addition the pattern is modified. The total gain can be as high as 6 dB for horizontally polarization at the peak of the main lobe. I don't remember the exact value for vertical polarization but think it the same. For real ground the Brewster's angle and other complications arise. Of course in all cases it varies with the take off angle and the height above the ground. A fairer comparison would be between an elevated ground plane (ground plane antenna or whip on a car top) and an elevated vertical dipole both at a fixed distance above a perfect or real ground. The dipole will have slightly higher gain. Rather than introduce all of this complication, I think it best to simply delete the 3 dB gain statement. — Preceding unsigned comment added by JNRSTANLEY (talk • contribs) 14:56, 24 August 2017 (UTC) I checked the monopole article and it explains this better. In transferring that info to the whip article some important qualifications were lost. Even in the monopole article there is some possibility of misunderstanding. For example Some AM stations use a center fed vertical dipole raised above ground. This has gain over a quarter wave monopole. JNRSTANLEY (talk) 15:06, 24 August 2017 (UTC) I am open to anyone's ideas of how to make this more clear.JNRSTANLEY (talk) 17:35, 24 August 2017 (UTC)

Your points about the dipole are well taken and I agree with your concerns. However I feel the article needs to have some gain numbers; we should not just omit them. The article could just say that the λ/4 whip has a gain of 5.19 dBi when mounted over a perfect infinite ground plane, without mentioning the comparison with the dipole. --Chetvorno^TALK 21:43, 24 August 2017 (UTC)

Sounds good. Lets go with that for now. I will make the change. JNRSTANLEY (talk) 10:47, 25 August 2017 (UTC)

Captions

Some of the captions could be wrong. The example cell-phone antenna is not base loaded. It is a 900 MHz 5/8 wave antenna. The tower-mounted fiberglass antennas appear to be 1/2 wave dipoles, since there is no counterpoise or visible loading coil. The Uninvited Co., Inc. 21:55, 9 February 2018 (UTC)