Appendix B: Definitions - Nokia NPD-4 Series Technical Documentation Manual

CCS Technical Documentation

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
Issue 1 02/2003
Nokia Corporation
Troubleshooting — RF
Confidential
NPD-4
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