FMCW radar performance

1
FMCW radar performance and cost
2
FMCW radar design

• FMCW radar - key design questions
• The needs of the users
• Required sensitivity
• Range resolution
• Doppler capability
• Polarimetric capability
• Specification of instrument preliminary to
  detailed design
• Dual or single antenna
• Tx power (solid state amplifier type)
• Key instrument design features to permit later
  upgrades
• Quality if signal
• Constraints of Functionality vs Cost
• How many do we foresee being sold/deployed?
• What features are likely to raise the costs
  above an acceptable threshold?

3
FMCW radar - Objectives
Radar development - activity objectives Maximisi
ng sensitivity to be a key objective. Aiming to
see most cloud types and fog - -45dBz at a range
of 2km. Range resolution should be manually
selectable depending on the target type.
(15-30 metres typically for fog) Maximum
range 12 13 km. Minimum near-field range 50
metres Doppler capability would not require
additional hardware but would reduce sensitivity
seen as a second order
requirement. Signal purity was going to be very
important. Polarimetry seen as a third order
need and would require additional hardware -
increasing the cost. The radar unit needs to be
rugged and robust for non-specialist users. The
radars will eventually be deployed in a range of
climates the units will need to be
weather proof, and be air-conditioned to maintain
temperature control.

4
One specification for an FMCW cloud radar
The specification below is intended as an
indication of the performance that can be
expected from a FMCW cloud radar that makes use
of components available commercially.

Frequency of choice 94 GHz Antenna
configuration Dual antenna system
30 cm diameter horn antennas Beamwidth 0.55
degrees Transmit Power 400 mW
(26dBm) Receiver Noise Figure 6.5 dB Range
resolution 60 metres Pulse length 1
msec Pulse Repetition Frequency 1 kHz
5
FMCW radar performance figures
Radar sensitivity can be improved by integrating
pulses so it is anticipated that At a range of
2 km, the sensitivity would be 39 dBz
when integrating for 1 second. At a
range of 2 km, the sensitivity would be 44 dBz
when integrating for 10 seconds. At a
range of 10 km, the sensitivity would be -37
dBz when integrating for 60 seconds.

6
FMCW development time and cost estimates

• The following estimates of development time and
  costs of a prototype
• are for guidance only at this stage
• Development time 1 year
• Development costs (components and manpower)
  200K Euros

The objective would be to produce systems for
sale at below 100K Euros