The LinearFMWaveform object creates a linear
FM pulse waveform.

To obtain waveform samples:

Define and set up your linear FM waveform. See Construction.

Call step to generate the linear
FM waveform samples according to the properties of phased.LinearFMWaveform.
The behavior of step is specific to each object in
the toolbox.

Construction

H = phased.LinearFMWaveform creates a linear
FM pulse waveform System object™, H. The object
generates samples of a linear FM pulse waveform.

H = phased.LinearFMWaveform(Name,Value) creates
a linear FM pulse waveform object, H, with each
specified property Name set to the specified Value. You can specify
additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

Properties

SampleRate

Sample rate

Specify the sample rate, in hertz, as a positive scalar. The
quantity (SampleRate ./ PRF) is a scalar or vector
that must contain only integers. The default value of this property
corresponds to 1 MHz.

Default: 1e6

PulseWidth

Pulse width

Specify the length of each pulse (in seconds) as a positive
scalar. The value must satisfy PulseWidth <= 1./PRF.

Default: 50e-6

PRF

Pulse repetition frequency

Specify the pulse repetition frequency (in hertz) as a scalar
or a row vector. The default value of this property corresponds to
10 kHz.

To implement a constant PRF, specify PRF as
a positive scalar. To implement a staggered PRF, specify PRF as
a row vector with positive elements. When PRF is
a vector, the output pulses use successive elements of the vector
as the PRF. If the last element of the vector is reached, the process
continues cyclically with the first element of the vector.

The value of this property must satisfy these constraints:

PRF is less than or equal to (1/PulseWidth).

(SampleRate ./ PRF) is a scalar
or vector that contains only integers.

Default: 1e4

SweepBandwidth

FM sweep bandwidth

Specify the bandwidth of the linear FM sweeping (in hertz) as
a positive scalar. The default value corresponds to 100 kHz.

Default: 1e5

SweepDirection

FM sweep direction

Specify the direction of the linear FM sweep as one of 'Up' or 'Down'.

Default: 'Up'

SweepInterval

Location of FM sweep interval

If you set this property value to 'Positive',
the waveform sweeps in the interval between 0 and B, where B is the SweepBandwidth property
value. If you set this property value to 'Symmetric',
the waveform sweeps in the interval between –B/2 and B/2.

Default: 'Positive'

Envelope

Envelope function

Specify the envelope function as one of 'Rectangular' or 'Gaussian'.

Default: 'Rectangular'

OutputFormat

Output signal format

Specify the format of the output signal as one of 'Pulses' or 'Samples'.
When you set the OutputFormat property to 'Pulses',
the output of the step method is in the form of multiple
pulses. In this case, the number of pulses is the value of the NumPulses property.

When you set the OutputFormat property
to 'Samples', the output of the step method
is in the form of multiple samples. In this case, the number of samples
is the value of the NumSamples property.

Default: 'Pulses'

NumSamples

Number of samples in output

Specify the number of samples in the output of the step method
as a positive integer. This property applies only when you set the OutputFormat property
to 'Samples'.

Default: 100

NumPulses

Number of pulses in output

Specify the number of pulses in the output of the step method
as a positive integer. This property applies only when you set the OutputFormat property
to 'Pulses'.