Juniper ACX500 Hardware Manual page 118

• Grounding plane
• Cable routing
We recommend the guidelines and procedure described in this chapter to ensure optimum GNSS signal
reception for the ACX500 router.
Requirements for Installing a GNSS Antenna
This section describes the requirements to correctly install a GNSS antenna on an ACX500 router.
31 on page 109 lists the items that you must provide to install the GNSS antenna.
Table 31: Antenna Mounting Requirements
Item
GNSS L1/G1 antenna with a frequency band of 1575 to 1610 MHz +/-10 MHz, 3 dB bandwidth
Antenna mount that is used to secure the GNSS antenna
Mounting area clear for at least two meters of any metal or other material that could act as a shield and block the
GNSS signal
360° unobstructed clear view of the sky from 15° above horizon
Clamps, cable ties, and so on, to secure cable
ACX500 Router GNSS Antenna Signal Gain Requirements
The ACX500 router requires an active GNSS antenna with built-in low-noise amplifier (LNA) for optimal
performance. The LNA amplifies the received satellite signals first to compensate the loss due to the
cable, and second to lift the signal amplitude to a range that is required by the receiver.
The cables and connectors that are used to connect the GNSS antenna to the receiver cause signal loss,
which can be up to 13 dB. The signal gain due to the LNA amplification can be up to 30 dB.
When calculating the required signal for the router, keep in mind the loss due to the cables and
connectors, and the gain due to the LNA amplification. Therefore, if the loss due to the cables and
connectors is 13 dB and the LNA signal gain is 30 dB, then the signal gain available to the receiver is
17 dB. We recommend that you limit the available gain to less than 35 dB. Also, ensure that the LNA
you select has a low noise profile.
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