Vector Signal Generators
SG390 Series — DC to 2 GHz, 4 GHz and 6 GHz vector signal generators

SG390 Series Vector Signal Generators· DC to 2 GHz, 4 GHz or 6 GHz· Dual baseband arb generators· Vector and analog modulation· I/Q modulation inputs (300 MHz RF BW)· ASK, FSK, MSK, PSK, QAM, VSB,
and custom I/Q· Presets for GSM, EDGE, W-CDMA,
APCO-25, DECT, NADC, PDC, ATSCDTV & TETRA· GPIB, RS-232 & Ethernet interfaces

Introducing the new SG390 Series Vector Signal Generators— high performance, affordable RF sources.
Three new RF Signal Generators, with carrier frequencies
from DC to 2.025 GHz, 4.050 GHz and 6.075 GHz, support
both analog and vector modulation. The instruments utilize
a new RF synthesis technique which provides spur free
outputs with low phase noise (–116 dBc/Hz at 1 GHz) andextraordinary frequency resolution (1 µHz at any frequency).
Both analog modulation and vector baseband generators areincluded as standard features.
The instruments use an ovenized SC-cut oscillator as thestandard timebase, providing a 100 fold improvement in thestability (and a 100 fold reduction in the in-close phase noise)compared to instruments which use a TCXO timebase.
A New Frequency Synthesis Technique
The SG390 Series Signal Generators are based on a new
frequency synthesis technique called Rational Approximation
Frequency Synthesis (RAFS). RAFS uses small integer
divisors in a conventional phase-locked loop (PLL) tosynthesize a frequency that would be close to the desired
frequency (typically within ±100 ppm) using the nominal PLL
reference frequency. The PLL reference frequency, which issourced by a voltage controlled crystal oscillator that is phaselocked to a dithered direct digital synthesizer, is adjusted sothat the PLL generates the exact frequency. Doing so provides
a high phase comparison frequency (typically 25 MHz)

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phone: (408)744-9040
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SG390 Series Vector Signal Generators

yielding low phase noise while moving the PLL reference
spurs far from the carrier where they can be easily removed.
The end result is an agile RF source with low phase noise,essentially infinite frequency resolution, without the spurs offractional-N synthesis or the cost of a YIG oscillator.
Analog Modulation
The SG390 Signal Generators offer a wide variety ofmodulation capabilities. Modes include amplitude modulation(AM), frequency modulation (FM), phase modulation (ΦM),
and pulse modulation. There is an internal modulation
source as well as an external modulation input. The internal
modulation source produces sine, ramp, saw, square, and noise
waveforms. An external modulation signal may be applied
to the rear-panel modulation input. The internal modulation
generator is available as an output on the rear panel.
Unlike traditional analog signal generators, the SG390 Series
can sweep continuously from DC to 62.5 MHz. And for
frequencies above 62.5 MHz, each sweep range covers morethan an octave.
Vector Modulation
The SG390 series builds upon this performance by adding
full support for vector signal modulation on RF carriers
between 400 MHz and 6.075 GHz. It features a dual, arbitrary
waveform generator operating at 125 MHz for baseband signal
generation. The generator has built-in support for the mostcommon vector modulation schemes: ASK, QPSK, DQPSK,
π/4 DQPSK, 8PSK, FSK, CPM. QAM (4 to 256), 8VSB, and
16VSB. It also includes built-in support for all the standard
pulse shaping filters used in digital communications: raised
cosine, root-raised cosine, Gaussian, rectangular, triangular,
and more. Lastly, it provides direct support for the controlled
injection of additive white Gaussian noise (AWGN) into thesignal path.

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Internal baseband generators
Using a novel architecture for I/Q modulation, the SG390
series provides quick, user-friendly waveform generation.
The baseband generator supports the playback of pure digital
data. It automatically maps digital symbols into a selected
I/Q constellation at symbol rates of up to 6 MHz and passes
the result through the selected pulse shaping filter to generate
a final waveform updated in real time at 125 MHz. This
baseband signal is then modulated onto an RF carrier using
standard IQ modulation techniques.
Preset communications protocols (GSM, GSM EDGE,
W-CDMA, APCO-25, DECT, NADC, PDC, TETRA, and
ATSC DTV) quickly configure the signal generator to thecorrect modulation type, symbol data rates, TDMA duty
cycles and digital waveform filters. The preset protocols also
configure the rear-panel TDMA, START of FRAME, andSYMBOL CLOCK digital outputs. The baseband generators
can be configured for these protocols without the use of
external computers or third party software.
The I/Q waveforms are computed in real time. Symbols are
mapped to constellations, digitally filtered, and up-sampled
to 125 Msps to drive the I/Q modulator via dual 14-bit DACs.
The symbols can be a fixed pattern, PRBS data from aninternal source, or come from a downloaded user list of up to
16 Mbits. The constellation mapping can be modified by theuser. Digital filters include Nyquist, root Nyquist, Gaussian,rectangular, linear, sinc, and user-defined FIR .
External I/Q Modulation
The rear-panel BNC I/Q modulation inputs and outputs
enable arbitrary vector modulation via an external source. The
external signal path supports more than 300 MHz of bandwidthwith a full scale range of ±0.5 V and a 50 Ω input impedance.

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SG390 Series Vector Signal Generators

Power vs Frequency

Easy Communication

All SRS RF signal generators have cascaded stages ofamplifiers and digital attenuators to drive the RF output.
Five stages can provide up to +25 dB of gain to -130 dB ofattenuation in 156 digitally controlled steps. During factory
calibration the output power is measured at 32 frequencies
per octave for each of the 156 attenuator steps to populate amemory matrix with about 40,000 elements. When set to aparticular frequency and power, the instrument interpolates
between these matrix elements to determine the best attenuatorsetting. An analog attenuator is used to provide 0.01 dB
resolution between matrix elements and to compensate forresidual thermal effects.

Remote operation is supported with GPIB, RS-232 andEthernet interfaces. All instrument functions can be controlled
and read over any of the interfaces. Up to nine instrument
configurations can be saved in non-volatile memory.

This method eliminates the need for precision attenuators
and automatic level controls (ALC) without any sacrifice inperformance. Eliminating the ALC also removes its unwanted
interactions with amplitude, pulse and I/Q modulation.
OCXO or Rubidium Timebase

Ordering Information

The SG390 Series come with a oven-controlled crystal
oscillator (OCXO) timebase. The timebase uses a third-overtone
stress-compensated 10 MHz resonator in a thermostaticallycontrolled oven. The timebase provides very low phase noiseand very low aging. An optional rubidium oscillator (Opt. 04)
may be ordered to substantially reduce frequency aging andimprove temperature stability. An external 10 MHz timebasereference may be supplied to the rear-panel timebase input.

SG392
SG394
SG396
Option 04
RM2U-S
RM2U-D

2 GHz signal generator
4 GHz signal generator
6 GHz signal generator
Rubidium timebase
Single rack mount kit
Dual rack mount kit

SG394 rear panel

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phone: (408)744-9040
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SG390 Series Specifications (Analog)

Residual FM (typ.)Residual AM (typ.)

Frequency Setting
Frequency ranges
SG392
SG394
SG396
Frequency resolution
Switching speed
Frequency error
Frequency stability

DC to 62.5 MHz (BNC output, all models)
950 kHz to 2.025 GHz (N-type output)
950 kHz to 4.05 GHz (N-type output)
950 kHz to 6.075 GHz (N-type output)
1 µHz at any frequency<8 ms (to within 1 ppm)<(10–18 + timebase error) × fC
1 × 10–11 (1 s Allan variance)

1 Hz rms (300 Hz to 3 kHz BW)
0.006 % rms (300 Hz to 3 kHz BW)* Spurs, phase noise and residual FM scale by 6 dB/octave to othercarrier frequencies

Front-Panel BNC Output
Frequency range
Amplitude
OffsetOffset resolution
Max. excursion
Amplitude resolution
Amplitude accuracy
Harmonics
Spurious
Output couplingUser load
Reverse protection

DC to 62.5 MHz
1.00 Vrms to 0.001 Vrms
±1.5 VDC
5 mV
1.817 V (amplitude + offset)
<1 %
±5 %
<–40 dBc<–75 dBc
DC, 50 Ω ±2 %50 Ω
±5 VDC

Front-Panel N-Type Output
Frequency range
SG392
SG394
SG396
Power output
SG392
SG394
SG396
Voltage output
SG392
SG394
SG396
Power resolution
Power accuracy
Output couplingUser load
VSWR
Reverse protection

950 kHz to 2.025 GHz
950 kHz to 4.050 GHz
950 kHz to 6.075 GHz+16.5 dBm to –110 dBm+16.5 dBm to –110 dBm (<3 GHz)
+16.5 dBm to –110 dBm (<4 GHz)
1.5 Vrms to 0.7 µVrms
1.5 Vrms to 0.7 µVrms (<3 GHz)
1.5 Vrms to 0.7 µVrms (<4 GHz)
0.01 dBm±1 dB
AC, 50 Ω
50 Ω<1.6
30 VDC, +25 dBm RF

Spectral Purity of the RF Output Referenced to 1 GHz*
Sub harmonics
Harmonics
Spurious<10 kHz offset>10 kHz offset
Phase noise (typ.)
10 Hz offset
1 kHz offset
20 kHz offset
1 MHz offset

None<–25 dBc (<+7 dBm, N-type output)<–65 dBc<–75 dBc–80 dBc/Hz–102 dBc/Hz–116 dBc/Hz (SG392 & SG394)–114 dBc/Hz (SG396)–130 dBc/Hz (SG392 & SG394)–124 dBc/Hz (SG396)

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Phase Setting on Front-Panel Outputs
Max. phase step
Phase resolution±360º
0.01º (DC to 100 MHz)
0.1º (100 MHz to 1 GHz)
1.0º (1 GHz to 8.1 GHz)

Standard OCXO Timebase
Oscillator type
Stability (0 to 45 ºC)
AgingOven controlled, 3rd OT, SC-cut crystal<±0.002 ppm<±0.05 ppm/year

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SG390 Series Specifications (Analog)

Rubidium Timebase (Opt. 04)
Oscillator typePhysics package
Stability (0 to 45 ºC)
Aging

SG396 power error(–30 dBm to +10 dBm, DC to 6 GHz)

Oven controlled, 3rd OT, SC-cut crystal
Rubidium vapor frequency discriminator<±0.0001 ppm<±0.001 ppm/year

Timebase Input
Frequency
Amplitude
Input impedance

10 MHz, ±2 ppm
0.5 to 4 Vpp (–2 dBm to +16 dBm)
50 Ω, AC coupled

Timebase Output
Frequency
SourceAmplitude

10 MHz, sine
50 Ω, DC transformer coupled
1.75 Vpp ±10 % (8.8 dBm ± 1 dBm)

Output Power Error
SG392 power error(–30 dBm to +10 dBm, DC to 2 GHz)Internal Modulation Source
Waveforms
Sine THD
Ramp linearity
Rate

Sine, ramp, saw, square, pulse, noise–80 dBc (typ. at 20 kHz)
<0.05 % (1 kHz)
1 µHz to 500 kHz(fC ≤ 62.5 MHz (SG392 & SG394))(fC ≤ 93.75 MHz (SG396))
1 µHz to 50 kHz(fC > 62.5 MHz (SG392 & SG394))(fC > 93.75 MHz (SG396))
Rate resolution
1 µHz
Rate error
1:231 + timebase error
Noise function
White Gaussian noise (rms = dev / 5)
Noise bandwidth
1 µHz < ENBW < 50 kHz
Pulse generator period 1 µs to 10 s
Pulse generator width 100 ns to 9999.9999 ms
Pulse timing resolution 5 ns
Pulse noise function
PRBS 25 – 219. Bit period (100 + 5N) ns
Modulation Waveform Output
SG394 power error(–30 dBm to +10 dBm, DC to 4 GHz)
Output impedanceUser load
AM, FM, ΦM
Pulse/Blank

50 Ω (for reverse termination)
Unterminated 50 Ω coax
±1 V for ± full deviation“Low” = 0 V, “High” = 3.3 VDCExternal Modulation Input
Modes
Unmodulated level
AM, FM, ΦM
Modulation bandwidth
Modulation distortion
Input impedance
Input offset
Pulse/Blank threshold

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AM, FM, ΦM, Pulse, Blank
0 V input for unmodulated carrier±1 V input for ± full deviation>100 kHz<–60 dB
100 kΩ<500 µV+1 VDC

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SG390 Series Specifications (Analog)

SG396

Amplitude Modulation
Range
Resolution
Modulation source
Modulation distortion
BNC output
N-type output
Modulation bandwidth

0 to 100 % (decreases above +7 dBm)
0.1 %Internal or external<1 % (fC < 62.5 MHz, fM = 1 kHz)
<3 % (fC > 62.5 MHz, fM = 1 kHz)>100 kHzFrequency Modulation
Frequency deviation
Minimum
Maximum (SG392 & SG394)
fC ≤ 62.5 MHz
62.5 MHz < fC ≤ 126.5625 MHz
126.5625 MHz < fC ≤ 253.125 MHz
253.125 MHz < fC ≤ 506.25 MHz
506.25 MHz < fC ≤ 1.0125 GHz
1.0125 GHz < fC ≤ 2.025 GHz
2.025 GHz < fC ≤ 4.050 GHz (SG394)
Maximum (SG396)
fC ≤ 93.75 MHz

Deviation resolution
Sweep source
Sweep distortion
Sweep offset
Sweep function

0.1 HzPhase Modulation

Smaller of fC or
64 MHz – fC
1 MHz
2 MHz
4 MHz
8 MHz
16 MHz32 MHzDeviation
Deviation resolution

Smaller of fC or
96 MHz – fC
1 MHz
2 MHz
4 MHz
8 MHz
16 MHz32 MHz93.75 MHz < fC ≤ 189.84375 MHz
189.8437 MHz < fC ≤ 379.6875 MHz
379.6875 MHz < fC ≤ 759.375 MHz
759.375 MHz < fC ≤ 1.51875 GHz
1.51875 GHz < fC ≤ 3.0375 GHz
3.0375 GHz < fC ≤ 6.075 GHz
Deviation resolution
0.1 HzDeviation accuracy<0.1 %(fC ≤ 62.5 MHz (SG392 & SG394))(fC ≤ 93.75 MHz (SG396))<3 %(fC > 62.5 MHz (SG392 & SG394))(fC > 93.75 MHz (SG396))
Modulation source
Internal or external
Modulation distortion <–60 dB (fC = 100 MHz, fM = fD =1 kHz)
Ext. FM carrier offset <1:1,000 of deviation
Modulation bandwidth 500 kHz(fC ≤ 62.5 MHz (SG392 & SG394))(fC ≤ 93.75 MHz (SG396))
100 kHz(fC > 62.5 MHz (SG392 & SG394))(fC > 93.75 MHz (SG396))

DC to 96 MHz
89.0625 MHz to 192.188 MHz
178.125 MHz to 384.375 MHz
356.25 MHz to 768.75 MHz
712.5 MHz to 1537.5 MHz
1425 MHz to 3075 MHz
2850 MHz to 6150 MHz
0.1 HzInternal or external<0.1 Hz + (deviation / 1,000)<1:1,000 of deviation
Triangle, ramp or sine up to 120 Hz

0 to 360º
0.01º to 100 MHz, 0.1º to 1 GHz,
1º above 1 GHz
Deviation accuracy<0.1 %(fC ≤ 62.5 MHz (SG392 & SG394))(fC ≤ 93.75 MHz (SG396))<3 %(fC > 62.5 MHz (SG392 & SG394))(fC > 93.75 MHz (SG396))
Modulation source
Internal or external
Modulation distortion <–60 dB (fC = 100 MHz, fM =1 kHz,ΦD = 50º)
Modulation bandwidth 500 kHz(fC > 62.5 MHz (SG392 & SG394))(fC > 93.75 MHz (SG396))
100 kHz(fC > 62.5 MHz (SG392 & SG394))(fC > 93.75 MHz (SG396))
Pulse/Blank Modulation
Pulse mode
Blank mode
On/Off ratio
BNC output
Type-N output
Pulse feed-throughTurn on/off delay
RF rise/fall time
Modulation source

Logic “High” turns RF “on”
Logic “High” turns RF “off”
70 dB
57 dB (fC ≤ 1 GHz)
40 dB (1 GHz ≤ fC < 4 GHz)
35 dB (fC ≥ 4 GHz)
10 % of carrier for 20 ns at turn on (typ.)
60 ns
20 ns
Internal or external pulse

GeneralFrequency Sweeps (Phase Continuous)Frequency span
Sweep ranges
SG392 & SG394

10 Hz to entire sweep range
DC to 64 MHz
59.375 MHz to 128.125 MHz
118.75 MHz to 256.25 MHz
237.5 MHz to 512.5 MHz
475 MHz to 1025 MHz
950 MHz to 2050 MHz
1900 MHz to 4100 MHz (SG394)

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Ethernet (LAN)GPIB
RS-232
Line power
Dimensions, weight
WeightWarranty

10/100 Base-T.TCP/IP & DHCP default
IEEE488.2
4800 to 115,200 baud, RTS/CTS flow
<90 W, 90 to 264 VAC, 47 to 63 Hz w/ PFC
8.5" × 3.5" × 13" (WHD)
10 lbs.
One year parts and labor on defects inmaterials and workmanshipphone: (408)744-9040
www.thinkSRS.com

SG390 Series Specifications (Vector)

External I/Q Modulation

Vector Modulation

Carrier frequency range 400 MHz to 2.025 GHz (SG392)
400 MHz to 4.05 GHz (SG394)
400 MHz to 6.075 GHz (SG396)
I/Q inputs
50 Ω, ±0.5 V (rear panel)
I/Q full scale input(I2 + Q2)1/2 = 0.5 V
Modulation bandwidth 300 MHz RF bandwidth
I or Q input offset<500 µV
Carrier suppression>40 dBc (>35 dBc above 4 GHz)

Modulation type
PSK derivatives
QAM derivatives
FSK derivatives
ASK derivatives
CMP derivatives
VSB derivatives
Preset modes

PSK, QAM, FSK, CPM, MSK,
ASK, VSB
PSK, BPSK, QPSK, OQPSK,DQPSK, π/4DQPSK, 8 PSK, 16 PSK,
3π/8 8 PSK
4, 16, 32, 64, 256
1-bit to 4-bit with deviations from0 to 6 MHz
1-bit to 4-bit
1-bit to 4-bit with modulation indicesfrom 0 to 1.0
8 and 16 (at rates to 12 MS/s)
GSM, GSM-EDGE, W-CDMA,
APCO-25, DECT, NADC, PDC,TETRA, ATSC DTV, and audio
clip (analog AM and FM)

Rear-Panel Markers
Type
Amplitude
Output impedance

Symbol Clock, Data Frame, TDMA,
and user-defined
0.5 to 4 Vpp (–2 dBm to +16 dBm)
50 Ω, AC coupled

EVM or FSK Errors
TETRA
EVM (typ.)Dual Baseband Generator (for Vector I/Q Modulation)
2 (I and Q)
Dual 14-bit at 125 MS/s
10 MHz, 3rd order Bessel LPF
Up to 16 Mbits
1 Hz to 6 MHz (1 µHz resolution)
1 to 9 bits (maps to constellation)
Default or user-defined constellation
User-defined symbols, built-in PRBS
generator, or settable pattern generator
PRBS length
2n – 1 (5 < n < 32)(31 to about 4.3 × 109 symbols)
Pattern Generator 16 bits
Digital Filtering
Filter type
Nyquist, Root Nyquist, Gaussian,
Rectangular, Linear, Sinc, User FIR
Filter length
24 symbols
Noise Impairments
Additive noise
White, GaussianLevel–70 dBc to –10 dBc(band limited by digital filter)(π/4 Diff Quad PSK, 24.3 kS/s, 420 MHz)
0.76 % (0 dBm)

TETRA constellation(420 MHz carrier)Channels
DAC data format
Reconstruction filter
Arb symbol memory
Symbol rate
Symbol length
Symbol mapping
Symbol source

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TETRA I-EYE diagram(420 MHz carrier)phone: (408)744-9040
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SG390 Series Specifications (Vector)

NADC
EVM (typ.)(π/4 Diff Quad PSK, 24.3 kS/s, 875 MHz)
0.33 % (0 dBm)

APCO-25
FSK error foreach symbol

NADC constellation(875 MHz carrier)

DECT
FSK error (typ.)

NADC I-Eye diagram(875 MHz carrier)

APCO-25
FSK error (typ.)(FSK2, 1.152 Mbps, 1.925 GHz)
1.5 % (0 dBm)

DECT constellation(1.925 GHz carrier)(FSK4-C4FM, 4.8 kS/s, 850 MHz)
0.46 % (0 dBm)
DECT I-Eye diagram(1.925 GHz carrier)
APCO-25 constellation(850 MHz carrier)

APCO-25
I-Eye diagram(850 MHz carrier)Stanford Research Systems

DECT error foreach symbol

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SG390 Series Specifications (Vector)

GSM
EVM (typ.)GSM
EVM (typ.)(GMSK, 270.833 kS/s, 935 MHz)
0.3 % (0 dBm)
(GMSK, 270.833 kS/s, 1.932 GHz)
0.6 % (0 dBm)

W-CDMA
EVM (typ.)(QPSK, 3.840 Mcps, 1.850 GHz)
1.7 % (0 dBm)

W-CDMA
constellation(1.85 GHz)

GSM constellation(9355 MHz carrier)

GSM I-Eye diagram(9355 MHz carrier)

W-CDMA
ACPR

GSM-EDGE
EVM (typ.)
GSM-EDGE
EVM (typ.)(3π/8 8PSK, 270.833 kS/s, 935 MHz)
0.3 % (0 dBm)
(3π/8 8PSK, 270.833 kS/s, 1.932 GHz)
0.5 % (0 dBm)

QAM256
EVM (typ.)(6 MS/s, 2.450 GHz)

1.1 % (0 dBm)

QAM256 constellation(2.45 GHz carrier)

GSM-EDGE constellation(935 MHz carrier)Stanford Research Systems

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SG390 Series Specifications (Vector)

QAM32
EVM (typ.)(6 MS/s, 5.800 GHz)
2.5 % (0 dBm)

QAM32 constellation(5.8 GHz carrier)

QAM32 I-Eye diagram(5.8 GHz carrier)

ATSC-DTVEVM (typ.)(8 VSB, 10.762 MS/s, 695 MHz)
2.2 % (0 dBm)

ATSC-DTV (8VSB) constellation(695 MHz carrier)Stanford Research Systems

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