SASARII XBand Imaging Radar Simulation Using Pulse Compression

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SASARII X-Band ImagingRadar Simulation
UsingPulse Compression

• PRESENTED BY M.L Sathekge

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AGENDA

• INTRODUCTION TO RADAR
• PROBLEM DESCRIPTION
• PROPOSED SOLUTIONS
• DESIGN STATISTICS
• SIMULATION TESTS AND RESULTS
• CONCLUSIONS

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INTRODUCTION TO RADAR THEORY
The filling of the Katse Dam in
Lesotho differential InSAR to the mapping of
ground deformation induced by the loading effect
of a large reservoir.
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PROBLEM DESCRIPTION

• Component limitations on the systems resolution
• - Filters for up-conversion and down-conversion
• - Noise generated by components
• - Non-linearity in Components
• Effect of an analog-to-digital converter (ADC)
  full-scale resolution on the systems resolution

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PROPOSED SOLUTIONS

• Solutions to filter limitations
• - 5th order Butterworth Filters
• - Good trade-off between filter roll-off
  and group delay
• Non-linearity and noise generated by components
• - Operation of mixers, splitters and amplifiers
  in their linear region
• Solution to ADC resolution limitations
• - A 14-bit ADC is used. The systems dynamic
  range is determined by its quantisation level.

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CHIRP RADAR SIMULATION
IF1 at 158MHz And IF2 At 1300MHz
DAC
Chirp Formation
I
RF _at_ 9300MHz
Delay
Q
I
Matched Filter
ADC
Receiver With two Down-Conversion Stages
Q
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Chirp Signal _at_ IF1(158MHz)
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Complex Chirp _at_ 158MHz
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DESIGN STATISTICS

• Transmission power is 3.5kW at frequency of
  9.3GHz
• Systems noise figure is 2dB and worst noise
  figure is 6dB
• The MDS is at 95dBm
• The Radars maximum range is 11538m.
• The signal to noise ratio at the receiver output
• after matched filtering is 3dB
• A 14bit ADC with a sample rate of 210MHz was
  used to sample
• the signal
• The ADCs quantisation voltage is 0.00012207V
• The receiver noise level is 666mV

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SIMULATION TEST

• Filter test
• 5th Butterworth VS 9th order Chebyshev Group
  Delay Response

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SIMULATION TEST

• Power Return Test
• Corner Reflector
• With 95dB
• Attenuation

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TEST RESULTS
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Non-linearity in Components
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Conclusions

• A 130dB attenuation sets the minimum
  detectable signal in the receiver
• In non-linearity test mixer inter-modulation
  products put stress on the filter roll-off (Sharp
  filter roll-off required), hence group delay.
• With a gain of 77.5dB the receivers MDS
  improved from 50dBm to
• -95dBm
• Pulse Integration (output stacking) must be done
  to improve the signal to noise ratio.
• Good care must be taken to operate RF components
  according to their specifications to avoid
  non-linearity