Antenna

The antenna is a directional UHF antenna to receive radiosonde signals in the 400MHz meteorological band. The antenna consists of six antenna segments for horizontal reception and one segment for upwards direction, Each horizontal segment is a folded ground plane antenna with a 60ì corner reflector, the gain of an antenna element, at 0ìelevation angle is 11dB(over half wave antenna),for the upwards direction, the antenna is equipped with a cross dipole. One antenna segment at a time is connected for the reception. The antenna switch is controlled to make the selection between seven directions by the position from the flying radiosonde GPS. The output signal of antenna is sent for further processing to receiver after being prefiltered and amplified by LNA.

Specification

Operating Frequency

400~406 MHz

The half-wave dipole antenna

Type of Polarization

Horizontal Polarization

Antenna Gain

5dB

Beam width 

60º (3dB)

Antenna Standing Wave Ratio

1.5

The directional Antenna

Type of Polarization

Vertical Polarization

Antenna Gain

8dB

Beam Width

H Side Symmetrical

60º (3dB)

E Side Asymmetrical

(0ìaugmentation direction)

50º (3db)

Antenna Standing Wave Ratio

1.5

Filter

Band width

403±6MHz (3dB)

Standing Wave 

2

Insertion Loss

2dB

Switches

Isolation

-18dB

Insertion Loss

1dB

LNA

Gain

22dB

Noise Figure 

1

Operating temperature

-40~+85

º