Mw<n> - Transmit waveforms

Mw<n> menu is used for defining the waveform to be used within a transmit sequence. The FIR downconversion filter and any windowing functions are also defined here. Applying windowing functions to the ADC samples when deriving IQ is a new functionality available in the RVP10. This will become more relevant as support for SSPA digital waveform synthesis evolves.

Number of pulse/filter definitions: 4

The maximum number of different transmit waveforms is 16.

Configure settings for each transmit waveform by typing Mw<n>, where n is the number of the pulse.

Example

Mw0 -
Pulse/Filter #0 (ID: "mw_0")
----------------------------------
Rx Intermediate Frequency  : 60.0000 MHz
  Pulse
  ---------
  Pulselength of transmit pulse : 0.32 usec
  Pulse index (aka 4-bit code): 0x0
  -
  Filter
  ----------
  Type <Matching> (0 - Bandpass; 1 - Matching) : 1

  Window Type:
   0: Blackman
   1: Blackman Exact
   2: Chevyshev
   3: Flat Top
   4: Hamming
   5: Hann
   6: Kaiser
   7: Rectangular
   8: Triangular
   9: Tukey
  Window type <Tukey> : 9
  Window edge (tapering, 0 to 0.5): 0.10

Intermediate frequency


Rx Intermediate Frequency  : 60.0000 MHz

Define the intermediate frequency of the receiver with the question Rx Intermediate Frequency. The limits are 6 ... 72 MHz.

The radar intermediate frequency can be selected separately for each pulse width, so that different width pulses can occupy different frequency bands if desired. The Tx and Rx intermediate frequencies can also be different from each other, so that the RF up-conversion chain for transmission can be different from the down-conversion chain for reception.

Transmit pulse

Pulselength of transmit pulse : 0.32 usec
Pulse index (aka 4-bit code): 0x0

The value of the question Pulselength of transmit pulse represents the entire time duration of the waveform, including whatever amplitude modulations may be included at the tails. This may be derived from the width of the pulse as observed in the Ps plot, or using an external oscilloscope. For more information, see Burst spectra and AFC plot (Ps).

Filter

Type <Matching> (0 - Bandpass; 1 - Matching) : 1

The RVP10 supports the legacy bandpass FIR filter used in the earlier RVP products. New to the RVP10 is supporting an idealized matched filter computed from the Pulse Length of Transmission and Rx Intermediate Frequency values. 

Window Type:
 0: Blackman
 1: Blackman Exact
 2: Chevyshev
 3: Flat Top
 4: Hamming
 5: Hann
 6: Kaiser
 7: Rectangular
 8: Triangular
 9: Tukey
Window type <Tukey>: 9

The question Window Type defines the type of windowing applied to the raw ADC samples when computing IQ. Use a rectangular window with the legacy RVP900, RVP8, or earlier RVP versions. The windowing functions here are as defined within MATLAB.

Window edge (tapering, 0 to 0.5): 0.10

The question Window edge (tapering, 0 to 0.5) defines how much window tapering is applied to the raw ADC samples when computing IQ. 0 means no tapering is present, giving the same output as the ‘rectangular’ window. A value of 0.1 implies that 10% of the ADC samples at the start and end of the burst pulse time domain are tapered. A value of 0.5 implies that 50 % on each side of the time domain are tapered, or in other words the windowing function would be applied to all ADC samples.