NPD-1
Troubleshooting — RF
CCS Technical Documentation
Page 52
Nokia Corporation Confidential
Issue 1 11/2002
APPENDIX B:
Definitions
ACPR
: Adjacent Channel Power Ratio. A ratio of power at an offset frequency as com-
pared to the power at the center frequency.
ADC
: Analog to Digital Converter
AGC
: Automatic Gain Control
AFC
: Automatic Frequency Control
CW:
Continuous Wave. This is a pure sine wave with no modulation such as CDMA or
FM.
DAC
: Digital to Analog Converter
dB
: A power ratio. Formula is 10log(power1/power2). It is used to denote differences,
such as gain or loss. Power1 and power2 are in linear units such as W or mW.
dBm
: A unit for an absolute power level. Formula is 10log(power in mW/1 mW).
LNA
: Low Noise Amplifier
LO:
Local Oscillator. This is a CW signal used to mix signals up or down to a different fre-
quency.
PA
: Power Amplifier
PDM
: Pulse Density Modulation. This is used for control signals. The density of a stream
of digital voltage pulses is varied proportionally to the desired control level, then it is
converted to an analog voltage used as the control signal.
PLL
: Phase Locked Loop. Used in Synthesizer circuits to generate an LO.
PPM
: part per million
RSSI
: Received Signal Strength Indicator