Quartzlock E6-SS User Handbook Manual - 2.1.1 Introduction
Model
E6-SS
Operation Manual
E6-SS Manual A5 29 September 2015
Page 7
2 Desk Top Universal Reference Source
2.1 Universal Reference Source
2.1.1 Introduction
The instrument is a synthesized source optimised for signal purity. A wide
range of output frequencies is provided, at output levels between –18 and
+13dBm. Various analogue and digital modulation modes are available.
The instrument is powered from a 12V DC supply with a maximum power
consumption of 6 watts.
A USB interface is provided. Communication can either use a set of simple
control codes, or a front end Windows graphic interface.
2.1.2 Technical Description
A block diagram is shown in FIG1
FIG 2 shows the front and rear panel layouts.
The basis of the source is two single chip fractional N synthesizers with built
in VCOs.
The first synthesizer (reference synthesizer) generates an intermediate
reference frequency between 50MHz and 56.5MHz in steps of 0.5MHz. The
reference input to the reference synthesizer is either the internal TCXO at
20MHz, or the external reference input at 10MHz. The reference synthesizer
operates in integer mode. The phase comparison frequency is 10MHz. The
VCO operates between 2GHz and 2.26GHz. The internal divider is 40.
The second (main) synthesizer generates directly the high range of output
frequencies between 100MHz and 3GHz. The internal VCO operates
between 1.5GHz and 3GHz, and lower frequencies are generated by binary
division using the internal divider. The divider range is 2 to 62. When using
the divider, the output is close to a square wave.
The low range of frequencies from 380kHz to 100MHz are generated by
external binary dividers with ratios between 2 and 64. ECL dividers are used,
with differential outputs.