Using an Antenna with GSG 5/6 Simulators

Technical & Application Notes

Orolia’s GSG 5 & 6 Essential GNSS Simulators meet all required regulations of the FCC and CE Mark for operation as electronic test equipment.

When using the GSG signal generator with an optional antenna, one must consider additional regulations controlling the radiation of GPS-like signals into the air.

In the USA, the GPS spectrum is controlled by the National Telecommunications and Information Administration (NTIA). Sections 8.3.28 and 8.3.29 of the Manual of Regulations and Procedures for Federal Radio Frequency Management
describe the restrictions.

Depending on your situation, you may need authorization from the FCC to operate at or near the level allowed by the NTIA. A Special Temporary Authorization (STA) or Experimental License may be required. For more information about this, refer to the FCC
web site.

Countries other than the USA may have their own regulations or restrictions, which you should be aware of and comply with before using the optional antenna.

Power Level Considerations

The NTIA restricts the maximum signal level to -140 dBm (24 MHz BW) as received from an isotropic antenna at a distance of 100 feet from the building where the test is being conducted. Therefore, the maximum power level output from the GSG Signal Generator may need to be limited to conform to this regulation.

For example, consider the following test setup:

Antenna distance to nearest exterior wall: 100 ft.
Antenna gain: 0 dB (omni antenna)
Cable loss, antenna to GSG: 0 dB (no cable used)

Using the free space loss calculation for radio propagation:

Loss (dB) = 20 log10 (4π * Distance / λ)
Where λ = wavelength: @ 1575 MHz= 19 cm = 0.62 ft
Distance = 200 ft total => 100 ft from antenna exterior wall + 100 ft to restricted perimeter
Loss = 72 dB = 20 log10 (4π * 200/0.62)