I think the length of a 1/2 wave dipole in feet is basically 468/f(MHz) where the ratio of the length to diameter is very large (wire antennas in the HF region, for example). Making the diameter of the elements larger does two things: it reduces the overall length of the antenna and increases the bandwidth of the dipole.
Sounds like a new product: and infinately short dipole useable over an infinately large range of frequencies! The only drawback is the diameter needs to be infinately large.... Oh well, can't have everything.... Best Regards, Michael Hopkins Manager, EMC Technologies Thermo Electron Control Technology Division EMC & ESD Simulation Solutions One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 [email protected] www.thermo.com/esd One Thermo, committed to integrity, intensity, innovation & involvement From: robert Macy [mailto:[email protected]] Sent: Wednesday, October 29, 2003 1:54 PM To: [email protected]; [email protected] Subject: Re: Effective length of half wave dipole >From Dave Cuthbert's comments to me regarding a 1/4 wavelength dipole; he said that the current moves down the rod as the rod becomes thicker, which implies that the current distribution absolutely determines the effective length. Was that "effective length" or "tuned length"? hmm However, the whole thing may start with the conductivity of real life materials... Interesting to see the others' comments. - Robert - Robert A. Macy, PE .. [email protected] 408 286 3985 . . . .. . . fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 On Wed, 29 Oct 2003 16:59:20 +0800 [email protected] wrote: > > > Dear all > > I got confused with the effective length of a half wave > dipole. > > 1) It is due to non-constant current distribution, or > > 2) It is due to the wave velocity in materials different > from that in > vacuum. > > > What do you think which one is correct? > > Regards > KC Chan > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
