Agilent Technologies 8960 10 Series Reference Manual page 508

Block Diagram
The discriminator audio has an uncalibrated volume control provided due to the high tolerances involved.
Typically the DDS mode is used to feed the MIC input of a radio, or it may simply be used as a general purpose
low distortion function generator.
Demodulated audio can be selected from either of two Demodulation Downconverters. 300 - 3000 Hz BPF, 750
usec de-emphasis, and expandor circuits can be individually applied to the receiver audio, or bypassed.
Audio echo can be selected to route the received audio to the front panel audio output connector.
RF Sources
The test set can contain two identical RF sources. The RF sources are used to provide analog or digitally
modulated RF carriers for use in parametric testing of mobile stations encompassing a variety of cellular radio
formats. In general, the sources have a frequency range of 45 MHz to 2.7 GHz and an amplitude range of -13
dBm to -135 dBm.
The RF sources consist of a Synthesized Signal Generator module followed by a Vector Output module and an
RF Attenuator module. Baseband modulation information is supplied to the RF sources from a Baseband
Generator module preceded by an Audio Section module. The various components which make up the test set
source system are described in the following sections.
Baseband Generators
The purpose of the Baseband Generator module is to provide, for the modulation type currently in effect,
properly formatted baseband signals to the modulation circuits on the RF Source modules.
The Baseband Generator performs several functions related to the generation and processing of these
base-band modulation signals. These are:
• Transform data and clock signals from the Protocol Processor module into base-band analog I-Q modulation signals for
the I-Q modulator in the Vector Output module
• Transform data from the Protocol Processor module into baseband FSK modulation for the FM modulator in the Signal
Generator module
• Provide baseband FM path source selection, gain adjustment and summing node for analog FM signals from the Audio
module and internally generated baseband FSK signals which are output to the FM modulator in the Signal Generator
module
• Transform burst and adjacent timeslot signals from the Protocol Processor module into baseband burst modulation signals
for the burst modulator in the Vector Output module
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