Radar sector scanning!

I want to scan from 0 to 45 degress azimuth scanning electronically. I made 1 degree beamwidth of 32dbi gain using 20 by 20 array. I couldn't understand radar scan URA example regarding the rotation of antenna. It states that rotational movement is not supported but howcome antenna scanned from -45 to 45? Any help

Answer 1

[Honglei Chen]

The example uses the electronic scanning, i.e., scanning the beam via changing the phase at each element. Also for simple rotation, it isn't too difficult to write one yourself. You just need to use a different orientation at each angle and then use rangeangle to compute the target angle relative to the array.

HTH

[Hassam Mahmood]

Can you please copy paste the code from the example which is changing the phase at each element? And with 1 degree beamwidth what do you mean by different orientation? Elaborate it further

[Honglei Chen]

In this example

http://www.mathworks.com/help/phased/examples/scan-radar-using-a-uniform-rectangular-array.html

The following section computes the needed phase shift at each element for a given direction

    % Calculate steering vector for current scan angle
    scanid = floor((m-1)/int_pulsenum) + 1;
    sv = steeringvec(fc,scangrid(scanid));
    w = conj(sv);

and then the weights is applied at the radiator to form the beam toward that direction

    txsig = radiator(txsig,tgtang,w);

HTH

[Hassam Mahmood]

Okay I get this code but what exactly is steering vector? Does it steer the beam in the mentioned direction?

[Honglei Chen]

Yes it steers the beam.

It looks like you are not familiar with the array processing subject. Here is a good article to start with

https://www.researchgate.net/publication/3321188_Two_Decades_of_Array_Signal_Processing_Research_The_Parametric_Approach

[Hassam Mahmood]

Thank you