RF OVERVIEW
Issue 1
Section 3
MCUK991001G8
Revision 0
– 12 –
Technical Guide
3.2.3 Antenna
The antenna is a fixed helical type.
A mechanical RF switch is used to route the RF signal from the external antenna for handsfree operation and test purposes.
3.2.4 Transmit and Receive
The transmit and receive paths of GD30/GD50 are covered in their own specific chapters later in this manual.
3.3 RF & Accessory Connector
In previous models the RF signal is routed to the accessory connector which contains a micro-switch. If the switch is open, the
RF signal is routed to the hands free unit. If it closed, the signal is routed back via the Main PCB to the antenna. This routing
of the RF signal up and down the Main PCB invariably has a finite power loss associated with it.
In addition, the GD30/GD50 has a limited PCB area and the routing of the RF signal in this way reduces further the available
PCB area required for the Dual Band circuit.
To alleviate these problems the RF connector is located close to the PA module. This reduces the loss and hence the PAs do
not have to be driven so hard. This allows the power supply voltage to be lower, thus improving battery performance.
