AlfaRadio AlfaSpid Rotator and Controller Instrukcja Użytkownika Pobierz pdf (Strona 2)

S-band ground station prototype for low-earth orbit nanosatellite missions

TELECOMUNICAŢII ● Anul LII, nr. 2/2009 65

2. Space communication system

architecture

The simplified space communication system ar-

chitecture, presented in Fig. 2.1, is splited into two

physically separated units: the nanosatellite trans-

ceiver and the ground station. The nanosatellite and

the ground station can communicate via a circular

polarized (LHCP/RHCP) link operating in some S-

band portion allocated to Earth-space communica-

tions or to amateur radio service. The ground station

has a modular architecture in order to meet different

communication requirements which are application

dependent. The station main sub-systems are:

– the elevation-azimuth motorized antenna;

– a radio unit (satellite or application dependent);

– the satellite tracking module;

– a GPS module for time synchronization;

– the TLE data update module.

3. Ground station prototype

implementation

Most of the components which are integrated in

sub-systems are commercial off-the-shelf radio hard-

ware and software. The components were selected to

meet the requirements imposed by the uplink and

downlink budgets for the first Romanian nanosatellite.

3.1. Elevation & Azimuth motorized antenna

sub-system

The ground antenna consists of a radio amateur

highly directional 3M (F/D= 0.4 ratio) parabolic mesh

dish antenna. The operating range of the antenna is

from 1 to 6 GHz and has 65% efficiency. The gain at

2400 MHz is more than 35 dBd and the -3dB beam

width is approximately 2.9°. The mesh minimizes

problems with wind loading on the mounting hard-

ware caused by periodic local windstorms. For dish

specifications – see Table 3.1.

Table 3.1

The 3 meter mesh dish specifications

(Efficiency 65%)

Frequency Gain [dBd] -3dB angle (degrees)

1296 MHz 30.3 5.7

2320 MHz 35.4 3.2

3456 MHz 38.8 2.1

5760 MHz 43.3 1.3

Weight 40 kg

Fig. 2.1. Basic Architecture of the S-Band Space Communication System.

1 2 3 4 5 6 7 8

Komentarze do niniejszej Instrukcji

Brak uwag

AlfaRadio AlfaSpid Rotator and Controller Instrukcja Użytkownika Strona 2

Komentarze do niniejszej Instrukcji

Powiązane produkty i podręczniki dla Nie AlfaRadio AlfaSpid Rotator and Controller