The simulation of loop antenna's radiation pattern on polar plot

[aredhel]

Hi there. I'm looking for help on the simulation of loop antenna's radiation pattern on polar plot. I am rather lost. I have read some things on the topic and even browsed through Matlab's HELP ... but I couldn't find anything that could teach me how to plot the radiation pattern. Help please or maybe recommend a book for me to refer to.

Thank you.

 

[RF-OM]

Re: Loop antenna

NEC program can do this task and it is free. You can find a lot of topics about NEC on this site.

 

[VSWR]

Re: Loop antenna

Radiation plot of loop antenna, dipole, etc in Matlab:

https://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=6569

 

[aredhel]

Re: Loop antenna

I am having trouble with the NEC. As for the link that VSWR gave, I used it and thank you alot, but my lecturer specifically wants us to use polar(). I've been trying to plot it but I have come to a dead end. Maybe I did something wrong. Anyone knows how to?

 

[RF-OM]

Re: Loop antenna

I am doing antenna work on very rare occasions, so I am not the best person to ask. I have a friend Azulykit, who is good antenna engineer and I will try to ask him to help you.

 

[disisku_22]

Re: Loop antenna

hi aredhel

please find the attachement, it will describe how to plot the radiation pattern on the polor plot.
note: reference level is the measured max power level

 

[Azulykit]

Re: Loop antenna

It sounds like you are trying to plot the radiation pattern in polar coordinates. Most calculus texts have sections describing various plotting techniques. The two most commonly used are cartesian (x y plots) and polar (r, Θ)

What you probably want is plot with each point defined by a vector (in the x-y plane) whose origin is at the coordinate axis and the direction is an angle, counter-clockwise from the x-axis. The vector length is the gain. Be careful about letting the length "reflect" through the origin for small values as this will produce a strange looking plot. You will probably want to plot amplitude (gain) using a dB scale. I usually truncate the amplitude at whatever value corresponds to the center of the plot to avoid having the plot pass through the center. Stopping at the center does not look weird the way it would if you allowed it to go through the origin and beyond. Plotting in cartesian coordinates avoids this issue, but then you want a polar plot.

The other warning is pay attention to the angular units (radians or degrees) when you prepare your plot.