1. Main Function
Main task of this antenna subsystem is to accurately track the satellite, provide RF (both uplink and downlink) channels with high quality for the satellite testing and controlling system and complement the efficient track and measurement to the satellite angles; also real-timely send the messages such as the status, mode and angle of operation, etc to the supervisory computer.
2. SPECIFICATION
2.1 RF specification
Electric Performance
| Item | Tx | Rx |
| Frequency (GHz) | 13.75~14.50 | 10.95~12.75 |
| Gain (dBi) | 58.6+20log(F/14.25) | 57.6+20log(F/12.50) |
| First Sidelobe | ≤-14dB | |
| Wide-angle Sidelobe | 90 percent of the sidelobe peak values satisfy the following envelope，the excess is less than 3dB，comply with ITU_R.S580-6 specifications.
29-25log (q) dBi （1°£q<20°） -3.5dBi （20°<q£26.3°） 32-25log (q) dBi （26.3°<q<48°） -10dBi （48°£q） |
|
| Polarization Mode | Tx&Rx：HLP&VLP | |
| Port-Port Isolation | Rx-Rx ≥30，Tx-Tx ≥30，Tx-Rx ≥85 | |
| Cross Polarization Isolation | 35dB on Axis and 30dB within 1dB contour | |
| Antenna Noise Temperature
（LNAInput Port） |
≤65K（Elevation of 20º, sunny day, gentle breeze） | |
| G/T (dB/K) （El=20º,LNAnoise temperature≤70K,
Clear Sky and Light Wind） |
³ 36.2+10lg (f/12.5GHz) dB/K | |
| VSWR | ≤1.30:1 | |
| Feed Insertion Loss(dB) | ≤0.60 | |
2.2 Mechanical Specification
| Item | Description |
| Output interface of feed | Tx: WR-75F waveguide interface
Rx: WR-75F waveguide interface |
| Feed | Frequency multiplex 4-port, corrugated conical horn |
| Antenna type | Modified antenna |
| Antenna diameter | 7.3m |
| Pedestal type | THA, azimuth-elevation (EL/AZ) type |
| Antenna travel | Azimuth: ±90°Continuous |
| Elevation: 5°~90°(Continuous) | |
| Antenna velocity (AZ/EL) | Slew Speed: 0.05 °/s (max) |
| Surface accuracy (steady wind: 50km/h, gust: 75km/h ) | Main reflector: ≤0.5mm (r.m.s.)
Sub reflector: ≤0.2mm (r.m.s.) |
| Antenna appearance | White |
| Environmental Condition
Normal Operation Wind Degraded Operation Wind Survival Wind Temperature Relative humidity Earthquake Rain Solar Radiation |
50km/h gusting to 75km/h
75km/h gusting to 97km/h 200km/h at EL=90° indoor: 5℃ to 45℃ outdoor:-35℃ to 55℃ outdoor: 100%;indoor:20%-90%,no dew. 0.3g horizontal, 0.1g vertical 100mm/h 1135W/m2 |
