Engineers know that you never get something for nothing. Occasionally, however, the laws of physics are kind, and a particular tradeoff provides significant value. With SPC’s Cheetah Cub software-gated PNA measurement system, customers get an unmatched cost-to-performance ratio.
Range-to-target and radio frequency are two of the most important variables when assessing whether an RCS measurement can be made using continuous-wave (CW) illumination. The following graphic indicates the regions within this two-dimensional variable space where CW RCS measurements are useful and highly effective.
| One-Way Range to Target | RCS Frequency Bands | ||||
| 0.01-2 GHz | 2-4 GHz | 4-8 GHz | 8-18 GHz | 18-110 GHz | |
| Below 30 ft |  |
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| 30 to 50 ft | |||||
| 50 to 70 ft | |||||
| 70 to 90 ft | |||||
| Above 90 ft | |||||
The following table represents the calculated performance of a Cheetah Cub measurement system relative to collecting RCS data with a performance network analyzer (PNA) only.
| Calculated RCS Sensitivity (dBsm)1 | |||||
| 2 GHz | 6 GHz | 10 GHz | 14 GHz | 18 GHz | |
| Cheetah Cub | -31.0 | -51.9 | -52.5 | -54.1 | -58.7 |
| PNA Only | -18.6 | -21.0 | -20.3 | -20.5 | -24.5 |
| 1 - Calculation based on: SNR = 20 dB, Range to target = 30 ft, PNA IFBW = 500 Hz, Antenna efficiency = 55%, Antenna beam width = 11° @ 18 GHz. The calculated sensitivity for the PNA only system is based on the PNA providing +4 dBm power from 2 to 18 GHz. | |||||
Cheetah Cub includes everything needed for making RCS measurements from 2 to 18 GHz. With optional hardware and software, a Cheetah Cub also supports near- and far-field antenna measurements as well as automated phased-array tuning. Cheetah Cubs are based on an optimized RF design that maximizes the performance available from a CW measurement system.