Antennas

Ground station antennas

Our ground station has two Yagui model X-Quad from Wimo for both 2 m and 70 cm bands.

Antenna used in 2 m band is the following:

Antenna used in 70 cm band is the following:

This table shows their characteristics, note the geometry of the 2m antenna that allows double polarization.

  2m X-Quad 70cm X-Quad
Elements 12 18
Gain 10,5 12,8 dBD
3dB HPBW horizontal  (E) 47 36 Deg
Vert. (H) 46 36 Deg
Front/Back ratio 19 21 dB
Max. power 1500 1000 Watt
Stacking distance  2,8 1,1 m
Length 1460 1270 mm
Width 730 220 mm
Height 2,3 1,6 Kg
Windload a 160km/h 74 48 N
Connector 2x N jacks
Connector for circular polarisationNo. 18047  18049

See the instruction manual here and here (70cm).

We can work in both vertical and horizontal polarization; moreover, if we use an emphaser we would work in LHCP and RHCP polarization.

In a radio-link between the satellite and the ground station we need circular polarization because radio waves passing through the Earth’s ionosphere are likewise subject to Faraday effect.  You can look up a better explanation in the book: Antenas, ediciones UPC, Cardama y otros. Tema 2: Propagación.  

The following figure shows the radiation pattern of both antennas:

No, we show you some photos of our antennas:

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