Difference between no steering and steervec in 0, 0 ?

Question

Lore DT 2019-6-2

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/465176-difference-between-no-steering-and-steervec-in-0-0

评论： Lore DT 2019-6-18

In phased array system toolbox, plotting the 3D response pattern of volumetric array geometries, I obtain different responses in two cases that seem similar: if I don't specify steering at all and if I specify "steervec(f, [0, 0])", as an example of this documentation:

https://it.mathworks.com/help/phased/ref/phased.steeringvector-system-object.html.

But, since this documentation says that [0, 0] is the default steering angle in ANG, how is it possible that whether specifying it or not returns to me two different responses? Does "no steering specified" means that, by default, the pattern is in the 0, 0 direction?

Thanks.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Lore DT 2019-6-2

UPDATE. Probably I've found a way: if I don't specifiy the value

'PropagationSpeed'

inside phased.SteeringVector, the two cases that I said before return the same response, as expected.

But now the question is: why does Matlab give me the possiblity to introduce the parameter 'PropagationSpeed' inside phased.SteeringVector if this returns me a different response pattern? What could be this new, different response?

Hope someone can explain me. Thank you.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Honglei Chen 2019-6-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/465176-difference-between-no-steering-and-steervec-in-0-0#answer_377553

Could you share how you invoke the two interfaces? From what you described? The two interfaces is a bit different in array definition. For a SteeringVector, it contains an array object which specifies the element positions in meters. That's why you need to specify the propagation speed. On the other hand, in steervec() function, the element positions are specified in wavelength, so no propagation speed is needed. The object interface is more versatile in the sense that it can handle wideband case too.

HTH