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What is different between isotropical and directivity antenna? thanks
Hi, Can somebody give some suggestions on any planar antenna designs which have a very good directivity i.e. farfield radiation focussed in one direction. thanks in advance. regards, abti Hi abti Could tell us what you means the"high directivity"of planar antenna.The limit directivity of (...)
anybody can give me some detail about st330.this is a kind of directivity antenna which design by Radio Frequency Systems.and i want to simulate it in supernec,but i don't know the size ,who can tell me?thanks!
The gap between high mm-wave band and far infrared is today a hot topic (0.1-10THz)! Usually, if you have a single antenna, lens is the approach you should go for in case you need high-directivity antenna. One of (many) problems is the reflection on the lens-air interface. EDIT: "patch antenna" ... you mean planar (...)
As an additional remark, the SRD regulations don't allow either a PA or a higher directivity antenna in this band. But the legal aspect may be irrelevant for a single application.
Hi Fellows, I am working on the design of an horn antenna. I have designed a horn antenna operating at 8 GHz frequency. directivity achieved with this antenna is 18dB. and a beamwidth of 22 degrees. I want to know, is the gain same as the directivity of the antenna. What is the (...)
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!
directivity of an antenna system towards a given direction(θ,φ) is the radiation intensity normalized by the corresponding isotropic intensity: D(θ,φ)=U(θ,φ)/Ui=U(θ,φ)=4πdP/PraddΩ Gain of an antenna system towards a given direction(θ,φ) is the total accepted power norma
Hello has all How can calculate the directivity and the gain of an antenna to simulate by CST. Thank you well
Hi Friends, Recently I use hfss to simulate a circular patch loaded with annualr ring antenna. S parameter is ok, but the directivity is below than 1. I seed the air with lambda/10, and the boundary is lambda/4 away from the radiation element, but the result is same. Anyone can give some advice? Thanks a lot! The parameter from hfss: htt
Hi snowboy if you compare total gain with total directivity?
My suggestion is to simulate the antenna in Simulator and you can see the gain / directivity. Otherwise you can refer any one of the simulator website where you can find some examples.
Hi,everyone We usually can see on Paper some antenna the design is High gain and high directivity. But I do not understand the antenna Gain and directivity have any to be different. I knew these two relational type is G(Gain)=radiation efficiency*D(directivity). But I did not understand to this (...)
Hello, how can I plot the directivity of an antenna in HFSS in dBi (relative to an isotropic antenna) since in the plot window I can only select dB for the measurement unit? Thank you
in CST we can parametrize our structure and then can perform parametrization and from the results of parametrization we can optimize of our structure. e.g for the desired S11 however i want to optimize the directivity of my antenna . is it possible to do in CST and if answer is yes whats the procedure to do it any suggestions, comments
Hi, everyone. I have a basic question about using MATLAB program to calculate the antenna directivity by using the field data. The field data are stored in a N-by-M array of magnitude of the E field, N is the phi angle from 0 degree to 360 degree and M is the theta angle from 0 degree to 180 degree. My calculation is basically converting the
Hi everyone I have faced a problem that the directivity of simulated antenna, half-wavelength slot antenna, is lower than 1 (an omni-directional dipole antenna ususally get 1.6 approximately ). Can any of you help me to figure out the problem. Thanks so much.
Hi there, I want to calculate directivity of the antenna in MATLAB. I have a matrix of 72*37 which are measured values in an anechoic chamber of radiation intensity at different values of theta and phy. The thing is i dont know MATLAB and its start of my project to take measurements. I want to plot directivity from these measurements. (...)
Hi guys, I'm using HFSS to simulate an antenna, and I've run into an interesting problem. The antenna is surrounded by a standard airbox, lambda/8 at the longest wavelength away from the antenna, as recommended. I'm interested in simulating the effect of an infinite ground plane on the antenna, so I use a perfect E (...)
Hello, I've designed a Metamaterial antenna working at 434MHz but it shows a negative directivity (-3.2 dB)?!! What do you think about this problem? thanks for help.
Hello, I am a bit confused about the notion of partial directivity and gain. According to textbooks and papers the total directivity is defined as the sum of the partial directivities (the same for gain). But the common practice to get the sum of two orthogonal vectors is to take the vector sum. i.e. Instead of G = G_phi + G_theta, shoul
Hi, I've just started studying about antennas and I'm not able to understand why we need to take phi and theta as pi and 2*pi or vice versa in directivity formula. Could anyone please explain this ? Thanks in advance.
With any antenna, gain equals directivity minus loss. Some antennas are resonant and should be tuned for the best matching at a specified frequency (s11 >10 dB). Wideband antennas are considered if their S11 is poorer over the band width. Low S11 means less RF power supplied from a transmitter is radiated, also in a (...)
How many ways we can measure the gain of antenna. What is the best method to measure the gain of antenna? Gain=f(eff,directivity) :!: :idea: :?:
Such as Impedance vs Frequency directivity pattern Elevation pattern Radiation impedance vs. wavelength Others
Dear Rayengine! If we consider lambda/2 dipole for example, it has directivity 2.15 dBi. Monopole with infinite ground causes radiating only to upper half space, so that directivity of monopole=directivity of relevant dipole+3dB In our case of lambda/2 dipole, its counterpart is lambda/4 monopole with D=2.15dBi+3dB=5.15dBi In prac
Dear Lupin, I need to calculate the directivity of linear and planar array. I have already calculated array factor. Can you help me in matlab. I will be very thankful to you
hi,interested paper to modify the gian and directivity of yagi antenna using log periodic technique. i hoe enjoy special thanks to dr.hassan sallabi to help me. pls thanks him
Hi, Do anybody know how to measure gain of an antenna? I am using Pringles can antenna, but not sure exactly what gain I am getting out of it...Plz help if you can Thanks Mitesh Hi! directivity of this type of antenna is around 8dBi. So the gain is slightly lower, you can count with 7dBi. Regards, eirp
Hi, I'm involved in a study of linear and planar phased arrays. I'm looking for formulas of directivity. I've been writing a code. The general formula of the directivity must be checked for particular cases (uniform array..). Can u help me? Thanks in advance Lupin
i just begin to do some job in this field, i want to know what should be considered when choosing the mobile antenna.thanks the gain ,the size ,the shape ,the weight&the directivity
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 So D1
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.
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. Regards Lupin
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.
max232, 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 (...)
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.
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 (...)
Hi, 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 (...)
Dear All 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
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
Have you tried to use Gain / directivity to calculate the radiation efficience? How is the result, still great than 1? Hi, 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.
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.
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.
hello svarun, 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 (...)
I can say we need more details about the required directivity in what application .. for simplicity why you don't try mono-pole antenna
HI 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 (...)
Simply, gain is directivity minus circuit losses. If losses are negligible, then directivity=gain.
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 (...)
obtain the gain/directivity with hfss and then use the formula G=4piAef/lambda^2