Compact Payload Test Range
The Compact Payload Test Range (CPTR) is used for radiating payload measurements to verify in-orbit performance of complex radiating systems, so as to eliminate the uncertainties caused by predicting system performance from measurements performed on the various units that make up the system.
In addition, engineers can measure other critical system parameters that are not normally verifiable by means of tests, such as EIRP, Group Delay, G/T, beam steering, and link budgets, on the integrated system.
The CPTR is a Compensated Compact Range, designed for low cross-polar performance. This allows the making of accurate measurements of communications payloads employing frequency re-use. The feed horns can be placed at different locations in the focal zone, causing the wave front to deviate from the normal range axis. By placing horns at a variety of positions, the performance of a complete up/downlink via a satellite for ground stations in different locations can be measured.
The CPTR at ESTEC has been operational since late 1990. It consists of a shielded anechoic chamber with a feed scanner room, an attached control room, and a test preparation area.
The equipment needed to operate the positioners and acquire the test data is located in the control room. The Electrical Ground Support Equipment (EGSE) required to operate the system under test is placed in the test preparation area and connected, via feed-throughs, into the CPTR.
Purpose
The CPTR has been designed to carry out antenna, Radar Cross Section (RCS), and radiating payload testing. It can assess measurement techniques and develop them for research and development projects and provides measurement services to ESA projects and external customers.
| Electrical characteristics | |
| Overall size | 16 x 11 x 25 metres |
| Inside size | 11 x 10 x 24 metres |
| Plane Wave Zone | 7 x 5 x 5 metres |
| Frequency Range (instrumentation) | 1.0 to 40 gigahertz |
| Amplitude Ripple | +/- 0.2 decibels |
| Phase Ripple | +/- 4 deg. C |
| Taper | 0.4 decibels |
| Environmental characteristics | |
| Cleanliness Class | 100.000 |
| Temperature | 20 deg. C +/- 2 deg. |
| Humidity | 50% +/- 10% |
| Positioners | |
| Test Positioner - Load Capacity | 5000 kilograms |
| Relectors | |
| Main Reflector Dimensions | 10.5 x 7.5 metres |
| Surface accuracy | 70 microns (peak to peak) |
For more information please contact Maurice Paquay, CPTR manager.
Maurice.Paquay @ esa.int
