Linear FM pulse waveform
The LinearFMWaveform object creates a linear FM pulse waveform.
To obtain waveform samples:
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).
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.
Specify the length of each pulse (in seconds) as a positive scalar. The value must satisfy PulseWidth <= 1./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:
FM sweep bandwidth
Specify the bandwidth of the linear FM sweeping (in hertz) as a positive scalar. The default value corresponds to 100 kHz.
FM sweep direction
Specify the direction of the linear FM sweep as one of 'Up' or 'Down'.
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.
Specify the envelope function as one of 'Rectangular' or 'Gaussian'.
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.
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'.
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'.
|bandwidth||Bandwidth of linear FM waveform|
|clone||Create linear FM waveform object with same property values|
|getMatchedFilter||Matched filter coefficients for waveform|
|getNumInputs||Number of expected inputs to step method|
|getNumOutputs||Number of outputs from step method|
|getStretchProcessor||Create stretch processor for waveform|
|isLocked||Locked status for input attributes and nontunable properties|
|plot||Plot linear FM pulse waveform|
|release||Allow property value and input characteristics changes|
|reset||Reset states of the linear FM waveform object|
|step||Samples of linear FM pulse waveform|
Create and plot an upsweep linear FM pulse waveform.
hw = phased.LinearFMWaveform('SweepBandwidth',1e5,... 'PulseWidth',1e-4); plot(hw);
 Levanon, N. and E. Mozeson. Radar Signals. Hoboken, NJ: John Wiley & Sons, 2004.
 Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGraw-Hill, 2005.