research about wide band/multi band antenna - Canadian TV, Computing and Home Theatre Forums

hosam171 · 2010-03-02, 12:22 PM

hello
i am an electrical engineer and i am taking antenna course and i need to do a reasearch about wide band/multi band antenna any one recommend any books or sites having explenation a bout this subject and definition to it

300ohm · 2010-03-02, 12:32 PM

We have Shorted Bowtie Loops in area 51 that you may be interested in looking at. X0560 is a nice one. Very wideband and the higher the frequencies, the more wideband it gets. Its possible to make an antenna that covers 2 Ghz to 10 Ghz from the SBL with just a simple rescaling.
Googling Ultra Wideband Antennas or UWB antennas will bring up many books.

stampeder · 2010-03-02, 12:32 PM

Hello, have a look in this thread:

Useful Antenna Design Books & Tutorials

How much are we allowed to help provide info for you? Is your professor okay with this? It would be a shame if you got into trouble.

Good luck with your studies.

hosam171 · 2010-03-02, 12:44 PM

i want to have some information any books that i can find what i want
i only find a product a bout it i need to know what is multi band/wide band antenna (definition only)

300ohm · 2010-03-02, 04:27 PM

Wideband antenna: http://en.wikipedia.org/wiki/Wideband

Multi-band antenna: http://en.wikipedia.org/wiki/Antenna_%28radio%29

Basically, a wideband antenna is one that covers a wide range of CONTINUOUS frequencies. Whereas a multi-band antenna covers multiple ranges of frequencies, but not necessarily continuous.

hosam171 · 2010-03-03, 05:38 PM

does UWB is combination of wide band and multi band antenna or is it another thing???

300ohm · 2010-03-03, 06:50 PM

UWB stands for Ultra Wide Band. I guess if the frequency range is > 500mhz, its Ultra.
http://en.wikipedia.org/wiki/Ultra-wideband

Some history of Wide Band antennas here : http://www.coe.montana.edu/ee/rwolff...B_antennas.pdf

ota_canuck · 2010-03-03, 08:59 PM

Isn't a VHF/FM/UHF combined antenna considered multiband ?

300ohm · 2010-03-03, 09:29 PM

Yep, as typically sold. But if its a full LPDA from 54 to 698 mhz, it would be an ultra wideband antenna and very very long. However, all (that I know of) commercial vhf/fm/uhf LPDA antennas cut out non TV sections to make it shorter, so then it is considered a multi-band antenna.

hosam171 · 2010-03-03, 11:19 PM

thanks lot for helping me i was cofused

ericball · 2010-03-04, 10:27 AM

Note that bandwidth is a function of the center frequency and the EM characteristics of the frequencies. Covering the entire 50-220MHz VHF band is considerably more difficult than the 400-800MHz UHF band because the VHF band is over 2 full octaves (frequency doubling), while the UHF band is only 1 octave. (A folded dipole has a bandwidth of around an octave.)

holl_ands · 2010-03-04, 11:23 AM

Frequency Independent Antennas were computer modeled in the last-50's/early-60's
at the Univ. of Illinois using Method of Moments (MoM) techniques...just like today,
except the computer runs cranked away for hours and hours and hours at a time:
http://www.ece.illinois.edu/about/history/timeline.html
http://www.ece.illinois.edu/about/history/antenna/
http://www.ece.illinois.edu/mediacen...a.pdf#antennas
LPDA, Zig-Zag LPA, Conical Log Spiral, Horn Antennas, et. al. all date back to this massive effort....
See page 8 for a list of inventors....you can find their patents at www.freepatentsonline.com
FREE registration required to access.

If you Google "frequency independent antennas" (FIA) you'll find lots of useful info...
And check out your Univ. library for various antenna books looking for chapters re FIA...
BTW, today, the term UWB antenna is also used....

Multi-Band antennas come in many flavors. Some simply slap a hi-freq section in front
of a lo-freq section (e.g. one LPDA in front of the other....or a UHF Yagi & a VHF LPDA).
And some actually intersperse the hi-freq elements within the lo-freq elements,
some magic made possible through modern computer optimization techniques:
http://www.warrenelectronics.com/antennas/cs1100.htm
http://ti.arc.nasa.gov/m/pub/295h/0295%20%28Lohn%29.pdf
http://alglobus.net/NASAwork/papers/...006Antenna.pdf

Only some Amateur Radio bands are conveniently located on harmonic frequencies.
For 2-4+ element antennas for the HF Band (2-30 MHz), it is fairly common to see
some "Trap Filters" inserted part way through each element to help the antenna
resonate on multiple frequencies. Several articles re "Traps" can be found here:
http://www.cebik.com/content/radio.html
FREE registration required to access.

And here's a Trap Loaded GPS antenna for much higher frequencies:
http://www.mitre.org/work/tech_paper.../triplegps.pdf

If you search for various articles....and on-line copies of Thesis submissions...you'll
find that there is a lot of current work adapting the Freq Indep antennas of the past
so that they fit onto a PCB artwork....or smaller....

300ohm · 2010-03-04, 12:53 PM

Quote:

Covering the entire 50-220MHz VHF band is considerably more difficult than the 400-800MHz UHF band because the VHF band is over 2 full octaves (frequency doubling), while the UHF band is only 1 octave. (A folded dipole has a bandwidth of around an octave.)

Yeah, defining Ultra Wide Band as more than one octave would be a better definition than the > 500 mhz definition wikipedia has.

2010-03-02, 12:22 PM	#1
hosam171 Rookie Join Date: Mar 2010 Posts: 4	research about wide band/multi band antenna hello i am an electrical engineer and i am taking antenna course and i need to do a reasearch about wide band/multi band antenna any one recommend any books or sites having explenation a bout this subject and definition to it

2010-03-02, 12:32 PM	#2
300ohm Veteran Join Date: Mar 2008 Location: Somewhere in Delaware on the flat side Posts: 7,002	We have Shorted Bowtie Loops in area 51 that you may be interested in looking at. X0560 is a nice one. Very wideband and the higher the frequencies, the more wideband it gets. Its possible to make an antenna that covers 2 Ghz to 10 Ghz from the SBL with just a simple rescaling. Googling Ultra Wideband Antennas or UWB antennas will bring up many books. __________________ My builds/plans (not the latest models) are located here.

2010-03-02, 04:27 PM	#5
300ohm Veteran Join Date: Mar 2008 Location: Somewhere in Delaware on the flat side Posts: 7,002	Wideband antenna: http://en.wikipedia.org/wiki/Wideband Multi-band antenna: http://en.wikipedia.org/wiki/Antenna_%28radio%29 Basically, a wideband antenna is one that covers a wide range of CONTINUOUS frequencies. Whereas a multi-band antenna covers multiple ranges of frequencies, but not necessarily continuous. __________________ My builds/plans (not the latest models) are located here.

2010-03-03, 05:38 PM	#6
hosam171 Rookie Join Date: Mar 2010 Posts: 4	does UWB is combination of wide band and multi band antenna or is it another thing??? Last edited by hosam171; 2010-03-03 at 06:34 PM.

2010-03-03, 06:50 PM	#7
300ohm Veteran Join Date: Mar 2008 Location: Somewhere in Delaware on the flat side Posts: 7,002	UWB stands for Ultra Wide Band. I guess if the frequency range is > 500mhz, its Ultra. http://en.wikipedia.org/wiki/Ultra-wideband Some history of Wide Band antennas here : http://www.coe.montana.edu/ee/rwolff...B_antennas.pdf __________________ My builds/plans (not the latest models) are located here.

2010-03-02, 12:32 PM	#3
stampeder OTA Forum Moderator Join Date: Jan 2005 Location: North Delta, BC (96Av x 116St) Posts: 23,338	Hello, have a look in this thread: Useful Antenna Design Books & Tutorials How much are we allowed to help provide info for you? Is your professor okay with this? It would be a shame if you got into trouble. Good luck with your studies.

2010-03-02, 12:44 PM	#4
hosam171 Rookie Join Date: Mar 2010 Posts: 4	i want to have some information any books that i can find what i want i only find a product a bout it i need to know what is multi band/wide band antenna (definition only)

2010-03-03, 08:59 PM	#8
ota_canuck Veteran Join Date: Mar 2009 Location: Dunnville, Ontario on the Grand River, North shore Lake Erie Posts: 2,405	Isn't a VHF/FM/UHF combined antenna considered multiband ?

2010-03-03, 09:29 PM	#9
300ohm Veteran Join Date: Mar 2008 Location: Somewhere in Delaware on the flat side Posts: 7,002	Yep, as typically sold. But if its a full LPDA from 54 to 698 mhz, it would be an ultra wideband antenna and very very long. However, all (that I know of) commercial vhf/fm/uhf LPDA antennas cut out non TV sections to make it shorter, so then it is considered a multi-band antenna. __________________ My builds/plans (not the latest models) are located here.

2010-03-03, 11:19 PM	#10
hosam171 Rookie Join Date: Mar 2010 Posts: 4	thanks lot for helping me i was cofused

2010-03-04, 10:27 AM	#11
ericball Join Date: Apr 2008 Posts: 172	Note that bandwidth is a function of the center frequency and the EM characteristics of the frequencies. Covering the entire 50-220MHz VHF band is considerably more difficult than the 400-800MHz UHF band because the VHF band is over 2 full octaves (frequency doubling), while the UHF band is only 1 octave. (A folded dipole has a bandwidth of around an octave.)

2010-03-04, 11:23 AM	#12
holl_ands Veteran Join Date: Nov 2008 Location: San Diego, CA Posts: 1,592	Frequency Independent Antennas were computer modeled in the last-50's/early-60's at the Univ. of Illinois using Method of Moments (MoM) techniques...just like today, except the computer runs cranked away for hours and hours and hours at a time: http://www.ece.illinois.edu/about/history/timeline.html http://www.ece.illinois.edu/about/history/antenna/ http://www.ece.illinois.edu/mediacen...a.pdf#antennas LPDA, Zig-Zag LPA, Conical Log Spiral, Horn Antennas, et. al. all date back to this massive effort.... See page 8 for a list of inventors....you can find their patents at www.freepatentsonline.com FREE registration required to access. If you Google "frequency independent antennas" (FIA) you'll find lots of useful info... And check out your Univ. library for various antenna books looking for chapters re FIA... BTW, today, the term UWB antenna is also used.... Multi-Band antennas come in many flavors. Some simply slap a hi-freq section in front of a lo-freq section (e.g. one LPDA in front of the other....or a UHF Yagi & a VHF LPDA). And some actually intersperse the hi-freq elements within the lo-freq elements, some magic made possible through modern computer optimization techniques: http://www.warrenelectronics.com/antennas/cs1100.htm http://ti.arc.nasa.gov/m/pub/295h/0295%20%28Lohn%29.pdf http://alglobus.net/NASAwork/papers/...006Antenna.pdf Only some Amateur Radio bands are conveniently located on harmonic frequencies. For 2-4+ element antennas for the HF Band (2-30 MHz), it is fairly common to see some "Trap Filters" inserted part way through each element to help the antenna resonate on multiple frequencies. Several articles re "Traps" can be found here: http://www.cebik.com/content/radio.html FREE registration required to access. And here's a Trap Loaded GPS antenna for much higher frequencies: http://www.mitre.org/work/tech_paper.../triplegps.pdf If you search for various articles....and on-line copies of Thesis submissions...you'll find that there is a lot of current work adapting the Freq Indep antennas of the past so that they fit onto a PCB artwork....or smaller....

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