If the radiation patter of an antenna
is cos(Teta) normaly it means that the directivity
is >1, so use tu be A*cos(Teta) with A>1...
All non omnidirectional antena has a directibity > 1
RF, Microwave, Antennas and Optics :: 31.03.2004 08:34 :: tapa :: Replies: 2 :: Views: 912
The basic concepts in antenna measurements are presented in this module. First, a brief description of antenna ranges and anechoic chambers is given. Second, the basic methods for measuring the far-field radiation patterns, the gain, the directivity, the radiation efficiency, the impedance and the polarization are discussed.
RF, Microwave, Antennas and Optics :: 12.04.2004 11:47 :: zubair :: Replies: 0 :: Views: 786
I used the version 3.0 and there was sonething to be improved..I mena for instance directivity computation...
I've no idea about the 4.0..does anyone have comments?
I agree, a trial version could help us.
Electromagnetic Design and Simulation :: 11.05.2004 05:53 :: Lupin :: Replies: 3 :: Views: 801
Not only microstrip antennas have been constructed on a PCB. I've heard that a complete Yagi (5 or7 elements) can be constructed on a PCB. Does anyone have the plans for a 5 or 7 element Yagi working at 915MHz? I'm also interested on any other antenna type that can be printed (but needs to have large gain and directivity). Thanks all.
RF, Microwave, Antennas and Optics :: 12.05.2004 00:07 :: exata :: Replies: 2 :: Views: 2862
The problems that you can get designing a PIFA for mobile depend by your system requirements: dimensions, directivity, bandwidth, gain, etc.
Must be finding the compromise among antenna dimensions and radiation characteristics.
Modifying the antenna geometry lead to smaller size. Inserting slots force the surface currents to (...)
RF, Microwave, Antennas and Optics :: 22.12.2004 10:20 :: vfone :: Replies: 10 :: Views: 2352
Passive, the gain you get is relative to either an isotropic(dBi) radiator or dipole(dBd). Should think in terms of directivity instead og gain.
RF, Microwave, Antennas and Optics :: 18.08.2004 18:46 :: frannk :: Replies: 2 :: Views: 1243
antenna gain is often quoted as EIRP, that is "Effective Isotropic Radiated Power", or the apparent power transmitted assuming that the antenna radiates equally in all directions, IE. the field is assumed to be spherical from a point source with an equal power transmitted in all directions. EIRP is the product of Power supplied to the (...)
Electronic Elementary Questions :: 20.08.2004 04:21 :: GlamZ :: Replies: 3 :: Views: 4098
I need help to simulate an antenna (extended inner conductor coaxial antenna) as shown in the figure (Fig2).
It should give properties similar to a 2-wire dipole antenna (radiation pattern, S11<-10dB, etc).
I've tried to simulate in HFSS. But i cannot get a compromise between low reflection loss and a 90degree (...)
RF, Microwave, Antennas and Optics :: 26.08.2004 03:49 :: huiyuzz :: Replies: 2 :: Views: 875
anybody know the st330 antenna.the antenna is design by Radio Frequency System. in many book,the sloping wire can get omni-directivity pattern.why the antenna st330 can have directivity? how they do it? who can tell me? and i want to know the value of the terminal.thanks!
RF, Microwave, Antennas and Optics :: 10.09.2004 11:22 :: 105s :: Replies: 0 :: Views: 591
Please I am a master student in iraq I am studying on Rectangular Micro strip antenna but I met many problems in (Radiation pattern, Input impedance, Radiation power, directivity, Energy stored, Q-factor, Input conductance, Gain, Efficiency) because there is no new sources in iraq please are their any one can help me to send me any sear
Analog Circuit Design :: 22.09.2004 02:34 :: rushdy :: Replies: 0 :: Views: 844
Lets say I have a monopole antenna and S11 for this monopole is -5dB (in free space) over a certain frequency range. If I improve S11 from -5dB to -20dB over the same frequency range, would this be considered as a good improvement? In addition to the improvement in the S11, if I obtain 12 degrees of half power beamwidths both in E-pl
Electromagnetic Design and Simulation :: 09.10.2004 10:52 :: svarun :: Replies: 5 :: Views: 958
Have you tried to use Gain / directivity to calculate the radiation efficience? How is the result, still great than 1?
Gain/directivity ratio was the first thing I looked at and as expected in this scenario, it is greater than one. By the way , seeding the mesh in the airbox to λ0/6 also did not help.
Electromagnetic Design and Simulation :: 04.11.2004 13:40 :: svarun :: Replies: 16 :: Views: 6858
I hope to get some information about multi skirt antenna.
I don't know the exact spell.
It may be multi scot, multi scat, multi scott, and so on.
I attach the shape I found and the directivity I want.
The upper directivity graph is horizontal directivity.
And the lower one is vertical directivity.
Electromagnetic Design and Simulation :: 03.11.2004 18:21 :: Mingyu :: Replies: 2 :: Views: 707
i simulate a gsm dualband helical antenna in hsff. but the peak gain and directivity computed by hfss is always below -10dbi, this is obviously wrong, and the radiated power always large than the accept power, how it can be? But the radition pattern and return loss seem to be correct.
pls help me.
Electromagnetic Design and Simulation :: 10.11.2004 22:09 :: dirtypig :: Replies: 1 :: Views: 1170
your question says "... how big is good enough?" and I ask you, good enough for what?. Be aware that the ground plane size gives you an additional degree of freedom, and making it larger or smaller you can control the antenna beamwidth, and therefore the directivity.
If you want a directive antenna with low back radiation (...)
Electromagnetic Design and Simulation :: 09.12.2004 11:07 :: dowjones :: Replies: 10 :: Views: 2254
I can say we need more details about the required directivity in what application .. for simplicity why you don't try mono-pole antenna
RF, Microwave, Antennas and Optics :: 19.12.2004 16:06 :: armsgroup :: Replies: 2 :: Views: 665
backward radiation and forward radiation are related to main antenna lobe, forward radiation is the region were directivity (or gain) has its max value;
"backfire","endfire" and "broadside" are also related to the maximal value of directivity; in particular endfire means that radiation is max on direction along the array, in (...)
RF, Microwave, Antennas and Optics :: 23.03.2005 03:05 :: angie-filt :: Replies: 1 :: Views: 781
Simply, gain is directivity minus circuit losses. If losses are negligible, then directivity=gain.
RF, Microwave, Antennas and Optics :: 16.03.2005 08:16 :: edf :: Replies: 4 :: Views: 1404
hello ,everyone. Recently I have used HFSS to simulate two kinds of antenna (helical and microstrip antenna),I found all the parameters like gain ,directivity,pattern are correct except the antenna efficiency ,which is always highter than 1.
I was quite puzzled that it was obviously unreasonable for efficiency highter than (...)
Electromagnetic Design and Simulation :: 30.05.2005 06:58 :: cyriltighten :: Replies: 3 :: Views: 1357
obtain the gain/directivity with hfss and then use the formula
Electromagnetic Design and Simulation :: 08.06.2005 10:18 :: dowjones :: Replies: 1 :: Views: 652
it is a group of anntennas .
primary intention is to form high directivity or to achieve unidirectional casting
based on phase relations, they are classified into two types i)endfire ii)broadside arrays
A linear array of antenna elements which are spaced by lamda/2 apart and driven with alternating phases has its principle radiation maxi
Electronic Elementary Questions :: 23.06.2005 07:28 :: electronics_kumar :: Replies: 7 :: Views: 1323
I wold love to have derivations regarding loop antenna.the methametical derivations of its perametets like E & H fields ,Power ,directivity
Electromagnetic Design and Simulation :: 07.07.2005 17:56 :: saima :: Replies: 3 :: Views: 1611
Who can tell me how the Hfss caculate directivity?
why the directivity is so little(<1) in simulated microstrip antenna?
the directivity always should be more than 1,it's true?
Electromagnetic Design and Simulation :: 13.08.2005 05:34 :: lydu :: Replies: 0 :: Views: 568
There are many type of antennas in the world such as Dipole antenna, Monopole antenna, Patch antenna, PIFA (Planar Inverted F-type antenna), Slot antenna, CP (Circular polarization) antenna and so on.
Are there any web-sites or papers or books that introduce those (...)
RF, Microwave, Antennas and Optics :: 23.09.2005 23:19 :: crenyen :: Replies: 3 :: Views: 1598
dBi as an antenna measurement mean's dB over isotropic. An Isotropic radiator is an antenna that radiates equally in all directions. In other words, the radiation pattern look's like a perfect sphere.
Because antenna's are directional, the antenna directivity is measured as the peak of the radiation (...)
RF, Microwave, Antennas and Optics :: 02.11.2005 21:05 :: RFDave :: Replies: 3 :: Views: 667
you may also think about a printed dipole array above a reflecting plate. the directivity may be lower than a patch, but won't have the same bandwidth issues as noted by flatulent.
cavity distance will be relative to the wavelength in the dielectric, so size must be considered.
RF, Microwave, Antennas and Optics :: 10.11.2008 17:28 :: ghb :: Replies: 3 :: Views: 1197
i need program with matlab for antenna simulation that in first of program get "L" and give "E" and "H" and drawing "E" and "H" and get "f" and give antenna pattern 1D and 3D and get maximum input current (phase and amplitude) and give "radiated resistance" and directivity and drawing current of (...)
RF, Microwave, Antennas and Optics :: 14.12.2005 17:38 :: star22 :: Replies: 0 :: Views: 840
i need program with matlab for antenna simulation that in first of program get "L" and give "E" and "H" and drawing "E" and "H" and get "f" and give antenna pattern 1D and 3D and get maximum input current (phase and amplitude) and give "radiated resistance" and directivity and drawing current of antenna . and if (...)
Electromagnetic Design and Simulation :: 17.12.2005 04:23 :: star22 :: Replies: 5 :: Views: 1081
The gain of an antenna takes account of the antenna efficiency as well as its directivity. The formal definition of gain in any direction is "power density radiated in that direction divided by the power density which would have been radiated at that direction by a lossless (perfect) isotropic radiator having the same total accepted input (...)
Electronic Elementary Questions :: 26.12.2005 08:06 :: albert22 :: Replies: 2 :: Views: 1392
What is the difference between the two antenna parameters - Gain and directivity
Which is practical (not considering the ideal case of isotropic radiators)?
RF, Microwave, Antennas and Optics :: 06.01.2006 06:22 :: Lord Loh. :: Replies: 14 :: Views: 13060
Introducing the newest addition to the Diamond Engineering product line: the DAMS 6000 v5.0 antenna Measurement System
- DC-18 GHz Frequency Range----->not new
- Precision 2 axis Movement-------->Precision level??
- Accuracy to 1/8 of a degree--------> not good for high directi
RF, Microwave, Antennas and Optics :: 14.01.2006 11:29 :: g86 :: Replies: 3 :: Views: 1014
How can I put the directivity and gain in the same plot?
Electromagnetic Design and Simulation :: 09.02.2006 15:54 :: plasma :: Replies: 6 :: Views: 1739
Can I build any of these components on board:
- antenna (what about directivity and radiation pattern?)
Please help me in it in some details
Thanks alot in advance,
RF, Microwave, Antennas and Optics :: 11.03.2006 10:27 :: ahmad_abdulghany :: Replies: 4 :: Views: 629
Hi, what kind of antenna parameters do you want to test?
I think if you just want to measure the return loss (S11) or VSWR, then Network Analyzer is the only equipment you need. You just need to calibrate 1-port measurement of VNA, and then directly connect the VNA to your antenna, and read the S11 or VSWR from VNA.
If you want to measure the
RF, Microwave, Antennas and Optics :: 18.05.2006 20:00 :: winglj :: Replies: 5 :: Views: 914
I'm a little confused, so Gain here is not the (maximum directivity)*eff, but is diff. from the direction: directivity(theta,phi)*eff. ??
RF, Microwave, Antennas and Optics :: 27.06.2006 20:55 :: verashen :: Replies: 6 :: Views: 782
antenna can be of "resonnant" and "non-resonnant" type. TV antenna is resonant. It is selective.
antenna elements dimensions depend on frequency. But overall antenna dimensions depend ollso on parameters like wanted gain and directivity.
Try to search forum on this topics and you will find a lot of (...)
Electronic Elementary Questions :: 07.08.2006 04:18 :: Borber :: Replies: 5 :: Views: 848
directivity simly varies with size of antenna.
You can have a look on small antennas fudamental limits regarding relations between antenna size and other parameters for a better view.
Electromagnetic Design and Simulation :: 05.01.2007 05:38 :: AN56 :: Replies: 6 :: Views: 1183