# step

System object: phased.ElementDelay
Package: phased

Calculate delay for elements

## Syntax

`TAU = step(H,ANG)`

## Description

`TAU = step(H,ANG)` returns the delay `TAU` of each element relative to the array's phase center for the signal incident directions specified by `ANG`.

 Note:   The object performs an initialization the first time the `step` method is executed. This initialization locks nontunable properties and input specifications, such as dimensions, complexity, and data type of the input data. If you change a nontunable property or an input specification, the System object™ issues an error. To change nontunable properties or inputs, you must first call the `release` method to unlock the object.

## Input Arguments

 `H` Element delay object. `ANG` Signal incident directions in degrees. `ANG` can be either a 2-by-M matrix or a row vector of length M. If `ANG` is a 2-by-M matrix, each column of the matrix specifies the direction in the form [azimuth; elevation]. The azimuth angle must be between –180 and 180 degrees, inclusive. The elevation angle must be between –90 and 90 degrees, inclusive. If `ANG` is a row vector of length M, each element specifies a direction's azimuth angle. In this case, the corresponding elevation angle is assumed to be 0.

## Output Arguments

 `TAU` Delay in seconds.`TAU` is an N-by-M matrix, where N is the number of elements in the array. Each column of `TAU` contains the delays of the array elements for the corresponding direction specified in `ANG`.

## Examples

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### Element Delay for Uniform Linear Array

Calculate the element delay for a uniform linear array when the input is impinging on the array from 30 degrees azimuth and 20 degrees elevation.

```ha = phased.ULA('NumElements',4); hed = phased.ElementDelay('SensorArray',ha); tau = step(hed,[30;20])```