Antenna radiation plots can be quite complex because, in the real world they are three-dimensional. However, for simplification, a Cartesian coordinate system (a two-dimensional system which refers to points in free space) is often used. Radiation plots are most often shown in either the plane of the axis of the antenna or the plane perpendicular to the axis and are referred to as the azimuth or "E-plane" and the elevation or "H-plane" respectively.

There are generally two types of radiation pattern shown for each antenna:

• Azimuth (i.e. the RF radiation pattern when viewed from above the antenna)
• Elevation (i.e. a side-on view of the antenna RF radiation pattern)

For measurements, you will need to be able to rotate the antenna. The receiving antenna is positioned exactly opposite i.e. parallel plane to the transmitting antenna, separated as far as possible. An appropriate measuring device is connected to the receiving antenna - an oscilloscope or a spectrum analyzer - connect a signal generator to the transmitting antenna and transmit a steady signal - typically a continuous wave - and take measurements at the receiving end...turn the transmitting antenna in steps of 5 degrees, and depending on the antenna being tested, you can measure right up to 180 degrees in each direction - clockwise and anti clockwise...or even a full circle; then plot it in MS Excel for the radiation pattern. (input the far-field range numbers into an excel format and generate 2D polar plots of those numbers. I have not used it, but I believe that feature is already built into MS Excel; it's called the Chart Wizard. You probably want the 'Radar' plot. Copy and paste the numbers into Excel, and if you don't have a complete 360-degree data set, then select the data and run the Chart Wizard.)

Here are some other useful links:

Antenna Radiation Patterns in the Real World

Dipole Radiation Patterns | Antenna Polar Diagram | Tutorial

You may also like to try this software: Polar plot

http://wifinigel.blogspot.in/2013/11/antenna-radiation-patterns-in-real-world.html

http://www.radio-electronics.com/info/antennas/dipole/radiation-patterns.php

I wish you good luck.

thank u all for you're answers.

Aparna: so how can i modify coordinates system in HFSS to see radiation pattern of antenna simulation, normally HFSS displays just spherical coordinates to see radiation pattern wich is normal.

i want to see variations on z axes of radiation besides teta and phi ???

First of all define the " far field setup"

Go to the project manager window --->right click on "radiation" ----> "insert far field setup" and set the range of phi and theta.

This complete your far field setup.

Now to display on the surface of antenna

Go to your model and select all the model

right click on the model---->plot feilds------> radiation field

A window will open and tick under "visible" and then apply.

With due respect to the answers above I guess you wish to plot the radiation pattern in a plane at a certain height above z-axis (for example 6 cm). You already know the procedure to plot radiation pattern as you have already shown the plots. Am i right?

Nitin Kumar : Nitin Kumar Nitin kumar: You're absolutely right, it's what i'm looking for.

Dear Radouane, this is really very tricky, and it will not give you any precise answer. Usually you can visualize the pattern in plane perpendicular to the plane of your antenna, in a parallel plane the shape most of the time will remain same only it will scale by some amount. Even though you may try this, estimate the angle theta for the desired value of z by following the method explained by Mr. Zahid above, let us say that for z=6cm and theta 45deg (the reference point is the global coordinate system, theta=0 deg parallel to z-axis i.e zx/yz plane and then increases as you move towards xy-plane, theta=90 in xy-plane.), then while plotting the 3D-polar plot choose all values of phi and the estimated theta. You can get an idea how the field will look like, but again this is not accurate just an estimate.

Thnaks, I have already tried this type of solution. :)