Transceiver Rh-9 - Rf Module - Nokia RH-9 Series Ccs Technical Documentation

CCS Technical Documentation

Transceiver RH-9 - RF Module

This section describes the RF module for the RH-9 transceiver. The RF module includes
the RF chip, VCO, PA and surrounding components.
RH-9 is a dualband E-GSM900/GSM1800 phone, with GPRS (Class 4).
The RF engine is based on a RF chip called Mjoelner which contains all the RF function-
ality including LNA`s and reference oscillator. The engine is build for single-sided compo-
nent mounting. The shielding of the engine is made through two cans with removable
lids. One shielding can is for the buffers – the PA and the antenna switch, the other
shielding can is for the Mjoelner RF-ASIC. The VCO is shielded in a separate shielding can
which is an integrated part of the Mjoelner shielding can. The division of the circuit
blocks in the two shielding cans is made on the basis that the attenuation between the
harmonics of the transmitter and the VCO signal (in Mjoelner) has to be very high. In
order to achieve the adequate attenuation, a reliable contact between the shield and the
PWB is important.
The control lines between the PA area and Mjoelner are routed in a quite layer and
decoupled in order to guard against the radiated spurious in the PA area.
The battery is a Janette BLC-2 internal battery. The engine uses an operating voltage of
2.8 V, except for the PA, which is connected to the battery.
The engine use internal antenna based on a superstrate loaded PIFA structure, which
means that the metal patch is placed between the dielectric material and the ground
plane. The interconnection between antenna and PWB allows disconnection of the
antenna through a special coaxial connector.
Issue 1 11/02 ãNokia Corporation
RH-9
System Module & UI
Page 73