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201 Threads found on edaboard.com: Directivity Antenna
Hello , the Sinuous antenna that i have built is dual polarized because it hase two orthogonal dipole feed,i have attached the diagram and farfield results of the simulation. this antena is dually polarized, i have used ludwig 3 on vertical /horizontal as shown in the attached photos. how can i interpret the ludwig 3 diagram and get the direct
What you are expecting that efficiency of antenna should be plotted against? As in antenna we always prefer to be in spherical co ordinate systems so theta is the most suitable candidate for efficiency and directivity of antenna. I am not all clear about your question of efficiency but what I gather that (...)
Hi, Can anyone tell me why does directivity of a directional antenna changes over frequency? For example, I designed a patch antenna with -10 dB bandwidth from 3-5GHz. By simulation I obtained the 2d plot of directivity vs frequency. directivity changes over frequency within 3-5 GHz. What may be the (...)
You need to increase the Ground plane size to increase the directivity. I changed the expression to -30*h + PatchX
Just the opposite, the definition of the directivity: is how much more of the transmitted power goes to certain direction, comparing to isotropic antenna. In other words, if you have a very directive pencil beam antenna, it's beamwidth will be very small...
For a short linear antenna (l<< lama) the received power increases in direct proportion to the length of the antenna? The higher the directivity of an antenna the wilder the beamwidth? Anyone has equation o prove these? Thank you so much.
Hi, I have some questions: For a short linear antenna (l << ) the received power increases indirect proportion to the length of the antenna? The higher the directivity of an antenna the wider the beamwidth? anyone can give me the formula to prove these. Thank you.
my antenna is in nano meter size... and got a frequency in 800 to 1000 thz. below -10 db of return loss.used Gold and silicon dioxide as matarial. got 4.81 dbi directivity.... but very very low minus scale efficiency... then i understood it was a port mistake... we can not simply generate the rectangular wave guide port for achiving thz frequency..
Besides all implementation details, some general properties of an electrically small antenna should be considered - the maximum achievable directivity is that of a small dipole (cosine law) - the smaller the antenna relative to wavelength, the higher it's resonance Q respectively the smaller it's bandwitdth, Q ~ 1/r? - the bandwidth of (...)
I have a measured data and I have been told that it is realized gain pattern values. Does that mean that these values are output from measurement instrument after some internal calibration.? And if so how can calculate the directivity from it, given that I have no information of input power and any other loss factors.?
hi, antenna parameters are efficiency, gain and directivity and not coverage area. patch antenna has high directivity with gain can be up to 5 to 7dB. refer to link below to know more about patch
The radiation gain is in fact the directivity which is calculated knowing that the power delivered to the antenna is totally absorb by the antenna. We compute also the radiation intensity (W/str) in one direction to the isotrope radiation intensity. The gain take into account the loss (dielectric and conductive) and the mismatch of the (...)
hi, E field is electrical field and H field is magnetic field. i would say most relevant gain and efficiency. from gain you got to know directivity and polarization of an antenna. from efficiency you know how much radiated power over input power for an antenna. E field plus H field with other parameters involve creates force on (...)
Same form (rod) can implement different antenna types, need to read the fine print. Generally, more length gives better vertical directivity of an omnidirectional antenna.
There are various reasons why received UHF field strength can't give a reliable distance indication 1. antenna directivity and polarization 2. multi-path propagation 3. wave diffraction, reflection and absorption by obstacles It can give a rough zone information, but not more. You can probably improve the results by using antenna (...)
Dear all Can anyone give me the matlab code for the follwoing problem? Write a Matlab progran to calculate & plot 1) Radiation Pattern. 2) directivity 3) Input resistance 4) Radiation Resistance of Dipole antenna having different lengths L=λ/4
I had simulated micro patch antenna for 2.4 ghz and I can find s11 but please explain procedures to find other results like far feild radiation, near feild,efficiency,gain,directivity and all parameters
Best e-book is the Google. By array-antenna, are you looking to build a Phased Array? Or just using multiple arrays to increase directivity and gain? I would've gone for Helical however...
antenna radation pattern measurement requires a test range (best an open area without obstacles), a reference antenna, a transmitter and a calibrated receiver. Details can be found in antenna textbooks and you can google commercial companies offering such service. The pattern is measured relative to a maximum directivity in (...)
HFSS allows you to plot 2D & 3D Polar as well as Rectangular plots with a variety of variables. For transmitting antenna designs, apart from the actual E-Field pattern there is a variable called Dir (or directivity) which is DirTotal, DirPhi, DirTheta, DirX,Y,Z etc. What is this though? I thought directivity is a ratio so its a number. (...)
antenna stray lobes depend on desired interference levels required for directivity reception or transmission. 15 dBi peak with 0dBi lobes may be adequate for some applications but for a RADAR signal it might need to be -40dBi depending on dynamic range of signals.
To add to previous post... the omnidirectional horizontal path and the dead spot on vertical, yields a meagre gain of only 2dBi . 0dB isotropic or 0 dBi is for a theoretical spherical antenna. This "rubber ducky" choice trades sensitivity with directional pattern or "directivity Gain" It does not control the transmit level, path loss or Receive
It is impossible to say what is important without considering the specific application because it changes so much. For satellite communications, directivity and polarization purity are very important. For handheld devices, directivity is usually a bad thing and polarization impurity is more tolerable. In high power systems, a good impedance matc
Do you know why the gain would be negative? What is the directivity of the antenna? Do you know the relationship between the two?
Hi, I've set up a pyramidal horn in CST MWS 2014 with the following properties: directivity: ~20dBi Design frequency: 10 GHz Waveguide measurements is standard EIA WR-90 x-band. I've simulated this with a E-field monitor and a farfield monitor and the plots for the farfield has good agreement with what was expected from the analysis
There are other issues such as Rican fading off tall buildings from GPS giving false position, so antenna directivity can be important to reject Rican fading noise. THe only azimuth Doppler track designs I have done used two separated quad helix antenna for 500 mile rocket range and azimuth tracking
The directivity values given are in dB. Look at the definition of dB: x in dB = 10*log(x). Any value smaller then 1 leads to negative dB value. Therefore you have a positive directivity but the representation in dB leads to negative values. Thus the directivity there is very small. Almost every antenna has regions with very (...)
Hello Everyone I am simulating an antenna at 193.5 THz frequency range (150-250 THz). The design is a simple Dielectric Resonator fed by a microstrip line. I am facing two problems: 1) I am getting the value of Gain to be more than directivity, i.e. My directivity = 12.47 and Gain =13.18 as shown in Figures below. Which means that my (...)
obtained negative antenna gain despite the positive directivity. This is caused by loss in the antenna: lossy dielectric material and conductor losses. On lossy substrates like FR4, the gain of patch antennas is pretty bad, and your simulation shows that if you include the dielectric losses (tand) in the simulation.
Well it depends if you exported gain, directivity or RCS. See pages 14-101 to 14-102 of the FEKO 6.3 User Manual for details on the *.ffe file.
hi all i am tring to plot the radiation pattern of a monopole printed antenna with cst (in gain ieee and polar plot with phi=0 and 90 degress and theta variable ) i got results where it shows that the results iaccurate and directivity less than one ie the radiation pattern is moving out of 0 db what mistake i commited in simulations the gain v
Is guided wavelength lambda g\lambda somehow related to directivity of a patch antenna?
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 (...)
Hai while i am doing simulation in ADS i am getting the directivity value is little bit higher than gain why this is. Please help me Thank you
Dear All... Good afternoon Can anyone describe the limitations of the parameter of antenna and other microstrip circuits such as return loss, efficiency, directivity, axial ratio etc. (for example the return must be less than -9.8 db upper and positive values are not permissible and VSWR must have the valve less than 2 for an antenna to (...)
Who says directivity monopole and dipole are same????????? Please read a few books antennas They both have an omni-directional pattern in azimuth Dave
Hi. I have simulated a dielectric λ/4 monopole antenna in (30-400 MHz).now I want to examine the results. So,I extracted gain , directivity and efficiency versus frequency (30-300 MHz) my directivity and gain are maximum in f=300 MHz (Dmax = 3.5 dB),while my resonant frequency is 125 MHz. actually, my efficiency is best in f=125 (...)
hi everyone,i have a project in hfss , i get good wsvr and s11 values but i cant have directivity and gain as i want. i uploaded my project here can anyone say what is wrong with my project ? 90907
i m beginner in hfss can u tell me how plot gain vs freq graph,radiation pattern,directivity vs frequency,co and cross polarization...if any doc then upload...pls help..
hello I have a Project called in designing miniature antenna with high directivity cavity Fabry Perrot I need help I use hfss
hello everyone.. i have design rectangular microstrip antenna but i dont know how to plot gain vs freq and radition pattern,directivity such parameter... also i m not able to find what that graph represent pls help...
Sorry i run CST. In CST you add the FARFIELD option and you see how the antenna radiate the gain directivity etc.... i think it would similar in HFSS
hi, I trying to plot radiation resistance and directivity of Horizontal electric dipole, but i am not getting correct result as given in Balanis Book. I have also attached graph from Balanis Here is my code, PI = 4.0*atan(1.0); Wave_impe = 120.0*PI; h=5; L=1/50; A = L*PI; Io = 1; r=2; % U=zeros(2000,2000); UMAX=0; k=2*pi; i=0; j=1; a
Can u differentiate the gain from directivity?
hi i,ve designed a pifa antenna and simulated it with both ie3d and hfss, gain, s parameters, impedance and directivity are the same but electric field pattern are not!, i know this is caused by difference in method of MOM and FEM but how can i scale voltage source in IE3D or power source in HFSS to get the same electric field pattern regards.
What substrate material do you use, respectively what is the tangent loss factor of the material? When you have a good directivity but low gain it is often because of a high loss substrate. Also a wrong height could be responsible. sandipm14, please don't copy text form wikipedia.
I am learning question 15, It tries to relate directivity with effective area by using two antenna A1 and A2. I can follow the derivation to the last part where we let P_1\;=\;P_2. Then it said according to reciprocity, P_{1-2}
Ferrite rods offer the small size and a good directivity. In basic textbooks you can learn the details
Hi, I'm designing a 4X1 microstrip patch array antenna (microstrip line feed) at 2.4-2.5 GHZ band using ADS the parameters i m getting are returnloss = -25.8 db directivity is 12.65 dbi gain= 12.7dbi the problem is that im getting very narrow bandwidth of only ~30MHZ, how can i increase it so it'll cover most of the 2
what is the required diameter of a conical horn antenna operating at 3Ghz with 14dBI gain? what should be the value of directivity for required gain? will you please help me out? All answers to your questions you can find in any antenna textbook, please try to find one. I do not understand what you really