Antenna Requirements - Garmin GDL 90 Installation Manual

General Information
1.3.7

Antenna Requirements

1.3.7.1 GPS Antennas
The GDL 90 may be installed with the Garmin AT A-33 and A-34 GPS antennas. The following table
summarizes the antenna identification.
Model/Description
A-33, GPS WAAS
Antenna
A-34, GPS WAAS
Antenna
1.3.7.1.1 A-33 (590-1104)
Early production runs of PN 590-1104 were marked with TSO-C129a. This antenna was re-qualified to
TSO-C144 with no changes to the antenna. P/N 590-1104 antennas marked with TSO-C129a
identification are identical to those marked with TSO-C144.
Applicable TSO.......................................................... TSO-C144 (RTCA/DO-228 with Change No. 1)
Frequency...................................................... 1575 MHz
Polarization ................................................... Right Hand Circular
Axial Ratio .................................................... 3 dB Max at bore site
Radiation Coverage....................................... Elevation Angle
Finish............................................................. Polyurethane Enamel
Weight ........................................................... 3.9 oz. (0.11 kg)
Height............................................................ 0.61 inches (1.55 cm)
Operating Temperature .............................................. -55°C to +85°C
Operating Altitude...................................................... 55,000 feet (16,764m) max.
Amplifier:
Gain ........................................................ 26.5 dB ±2 dB
Noise Figure ........................................... 2.5 dB Max
Impedance............................................... 50 ohms
VSWR (Dry)........................................... < 1.5:1
VSWR (Rain) ......................................... < 2.0:1
Band Rejection ....................................... 35 dB
1-6
Mount Style
Screw Mount
Screw Mount,
Teardrop Footprint
560-1049-02 Rev. B
Part
Manufacturer
Number
Aero Antenna 575-9
Garmin AT 590-1104
Aero Antenna 575-93
Garmin AT 590-1112
Minimum Gain
>15º
10º
5º
0º
Order
Number
N/A
N/A
013-00113-00
013-00113-00
-2.0 dBic
-3.0 dBic
-4.5 dBic
-7.5 dBic
GDL 90 Installation Manual