Search Engine

193 Threads found on Directivity Antenna
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 (...)
You can do a relative directivity, where all the gain points are related to a maximum gain point. For example if you get an antenna gain pattern from 0 deg to 360 deg (step by 15 deg), and you get a maximum antenna gain at 30 deg, consider that gain point 0dB. Relate (in dB) all the other point measurements to this 0dB point, and finally you (...)
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.
hai, I designed a mimo antenna in HFSS v 13. In that, i reached a very good return loss and VSWR. Where as the gain of my antenna is 2dB and the directivity is about 5dB. Since the directivity is high when compared with gain, the efficiency of my antenna gets very low. Kindly, give some tips to improve (...)
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 2.4-2.5 GHZ band? THNA
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?
hi i ve designed 4X4 microstrip patch array antenna at 35GHZ using ADS the parameters i m getting are returnloss =-25.86 directivity is 18.56 dbi gain= 11.23dbi gain is very low so i want to ask that what is the range of the gain and how can i increase the gain my antenna plz guide me
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.
In Yagi -Uda antennas; the inductive nature of element is given to the reflector by choosing a length greater than resonant length; And for the director capacitive nature is given by choosing its length shorter than the resonant length; to acheive directivity of beam. What is the relationship between them? And what mechanism makes the element to
Is there a formula that related the 3dB beam width of a 1/2 wave dipole antenna with the gain of the antenna? Since the a narrower beam on a E field radiation represents more directivity, more gain. I was hoping there is a convenient formula where if you determine the 3db beam width from a antenna (...)
antenna gain is directivity is a given direction. One example where gain is not the only object is for antenna (typically parabolic dishes or segmented parabolic surface) used for space communication. Signal to noise is the main object. Higher antenna gain does not alway mean better signal to noise. In space (...)
What Dot4 has said : 1) radiation efficiency = conduction efficiency and dielectric efficiency 2) antenna efficiency = reflection efficiency, conduction efficiency and dielectric efficiency What drkirkby has said : polarisation loss and mismatch loss don't effect the gain. So as a result : G(Gain)=radiation efficiency*D(directivity) ( i believe
The polarisation of a linearly polarised antennna is by definition the direction of the electric field. All 4 of your diagrams show E plane plots. You have not drawn any H plane plots, which would be circular for a dipole. Two of your dipoles (A and C) are horizontally polarised, the other two (B and D) are vertically polarised. Knowing
Thanks for responding........I apologize in advance with all the trivial and meticulous questions. I hope you can understand what Im trying to ask. It is normal to talk of "azimuth" and "elevation" in antennas. If the antenna is vertically polarized, then the E-plane diagram shows you how the antenna behave with elevati