Page 7 - GNSS Simulation - A Guide to Testing

Conducted or Radiated Testing?

The choice between conducted or radiated testing will depend on whether your device or

receiver has an external antenna connection. With no external connection available, your test
signal must be radiated (Radiated Testing) so that the internal antenna can receive the signal. If
an external connection is available, then you can use Conducted Testing where the signal is
delivered directly via the test set-up.

Conducted testing

Conducted testing can be done where there is a direct antenna connection available on the unit
under test. In this case the simulator RF output is connected directly to the antenna input or, in

some cases, via fixed passive attenuators to further reduce the signal level.

Wired test setup using
attenuator

Radiated testing

Testing devices such as smart watches or cell phones with internal antennas is also possible but
adds some additional challenges. Radiated Testing introduces the risk of confusion between the
test signals and live GNSS signals. This combined with very strict legal restrictions on broadcast-

ing within the GNSS frequency band means that any radiated testing must be carried out within
a suitable RF shielded enclosure.

The small separation between the transmitter and receiver imposed by using a chamber in turn

means that very small differences in device position or environment can have a significant impact
on the received signal strength.

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