Gps Module - Nokia N900 Service Manual

RX-51
System Module
Bluetooth audio signals are sent to and from the device using a PCM and UART interface. The Bluetooth RF
signal is routed via a buried track to the Bluetooth antenna on the side of the PWB. An RF filter is needed
between the Bluetooth antenna and Bluetooth ASIC to prevent interference to and from the celluar phone
antenna. Phones that have both Bluetooth and WLAN use a shared antenna, as both services occupy the
2.4GHz ISM frequency band. The co-existence signaling interface between Bluetooth and WLAN ASICs controls
the RF activity in the shared frequency band.
The audio signal from the FM radio is routed via the phone Audio ASIC to the phone headset or loudspeaker.
The external wired headset is also used as an Antenna for the FM radio. The FM radio receiver RF signal is
routed from the ASIC via a buried track to an impedance matching circuit placed near the headset connector.
The following block diagram shows how Bluetooth-FM is connected to the host engine.
Figure 52 Bluetooth and FM radio block diagram

GPS module

RX-51 supports GPSCost4.0 release. GPS module is connected to cellular engine via I2C interface and GenIO
control signals. GPS clock configuration includes dedicated GPS TCXO and reference clock from Vapaus.
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