User Guide

PAMS Technical Documentation 3 - Audio System
NPE-4
Original ãNokia Corporation. Page 3-9
Deviations in gain performance:
Transmit gain absolute accuracy: -1.0 / 0.0 dB
Transmit gain variation (temperature, supply): +/- 0,7 dB
Transmit gain variation with frequency (300 – 3000 Hz): +/- 0,5 dB
Transmit gain variation with signal level (> -50 dBm0): +/- 0,5 dB
(<-50 dBm0: +/- 1.2 dB)
Receive gain absolute accuracy: +/- 0,5 dB
Receive gain variation (temperature, supply): +/- 0,7 dB
Receive gain variation with frequency (100 – 3000 Hz): +/- 0,5 dB
Receive gain variation with signal level (> -50 dBm0): +/- 0,5 dB
(<-50 dBm0: +/- 1.2 dB)
DSP Gain:
Initially the DSP gain uplink (Mic) is set to 12 dB and 0 dB downlink. This is done in the
Equaliser.
The AGC controled by the DSP is able to reduce the Uplink gain in the UEM by 18 dB
maximum in steps of 1.5 dB.
The DRC can either attenuate the signal or enhance in it in DSP by up to 10 dB.
Note: Local mode gains are uptimised for production testing and are not the same as in
normal mode.
Internal Audio Devices
NPE-4’s internal audio design is described in the following sections.
Earpiece
Receiver solution is selected to be a Kirk Acoustic earpiece. Earpiece design is leak toler-
ant with a front protection cover directly on the earpiece component. The Earpiece will
be placed in a moulded rubber gasket which seals the front cavity to the IMD Window.
In front of the earpiece and leakholes a shielding material will be placed to prevent dust
particles to migrate onto the earpiece diaphragm. This material consists of a grid mate-
rial type Saati PES 120/41 from Tradex (It is the same material as in Nokia 8210).
The earpiece is designed to be approved in type approval by type 3.2, low leak artificial
ear (Ear Simulator Type 4195, Low Leakage). No support for type 1 artificial ear is made
(Ear Simulator Type 4185).