CAM-M8 - Data Sheet

UBX-15031574 - R04

Page 16 of 31

Production Information

1.19 Antenna

The CAM-M8 concurrent GNSS modules are designed with integrated GNSS chip antenna.

Optionally, the CAM-M8 series modules can be connected to an external GNSS antenna.

should be followed in order to maintain good performance of the on-board GNSS chip antenna.

For more information, see the CAM-M8 Hardware Integration Manual [1].

1.19.1 Embedded antenna

The CAM-M8 series modules have an embedded GNSS antenna and the signal is further filtered and

amplified by internal Low Noise Amplifier (LNA), which is available at the

RF_OUT output. The

antenna signal

RF_OUT shall be connected externally to RF_IN Antenna Input signal via a short trace

between pads. For more information, see the CAM-M8 Hardware Integration Manual [1].

1.19.2 External GPS/GLONASS antenna connectivity

The customer may use an external active GNSS antenna connected via an external RF-switch. It is

suggested that the active antenna has a net gain including cable loss in the range from +10 dB to

+30 dB. Specified sensitivity is measured with an external low noise (NF < 1dB, G > 15dB) amplifier.

The antenna shall provide simultaneous reception of both GPS 1575 MHz and GLONASS bands 1598

to 1606 MHz.

antenna option, see the CAM-M8 Hardware Integration Manual [1].

1.19.3 Active antenna control (LNA_EN)

The

LNA_EN Pin can be used to turn on and off an external LNA or an active antenna. This reduces

power consumption in Power Save Mode (Backup mode).

LNA_EN signal. For more information, see the CAM-M8 Hardware Integration Manual [1].

1.19.4 Embedded antenna operation

The embedded GNSS chip antenna provides optimal radiation efficiency 80% typ. with 80x40 mm

ground plane. The GNSS chip antenna provides linear polarization with peak gain 1.1 dBi and

radiation pattern optimized for portable devices. The chip antenna is insensitive to surroundings and

has high tolerance against frequency shifts. Figure 2 shows the typical free space radiation patterns

of the embedded GNSS chip antenna at 1575 GHz. However, on small ground plane widths, the

antenna gain and radiation efficiency is reduced.