SMG

The Rohde & Schwarz SMG is a classic, high-performance analog RF signal generator designed for versatile testing applications up to 1 GHz. Offering exceptional spectral purity, fast switching speeds, and precise modulation capabilities, the SMG remains a reliable standard in laboratory and production environments.

RF and Microwave Receiver Testing Signal Generation

Specifications

Frequency

Parameter	Value
Minimum Frequency	100 kHz
Maximum Frequency	1000 MHz
Frequency Resolution	1 Hz

Output

Parameter	Value
Maximum Output Power	+13 dBm (up to +19 dBm with overrange)
Output Power Range	-140 dBm to +13 dBm (settable to +19 dBm)
Phase Noise	<-126 dBc/Hz (typical -131 dBc/Hz) at 20 kHz offset (500 MHz carrier)

Modulation

Parameter	Value
Modulation	AM, FM, Phase (φM), Pulse (with SMG-B3 option)
Sweep Modes	Frequency sweep, RF level sweep (digital step sweep)
Internal Fixed AF Frequencies	40 Hz, 150 Hz, 300 Hz, 400 Hz, 1 kHz, 3 kHz, 6 kHz, 15 kHz
Internal AF Synthesizer Option SMG-B2 Frequency Range	10 Hz to 100 kHz
External Modulation Input Impedance	100 kOhm

General

Parameter	Value
Reference Oscillator	10 MHz crystal standard (high stability ovenized reference optional via SMG-B1)
Interfaces	GPIB (IEEE-488)
Display	Liquid crystal display (LCD) for all settings
Memory Storage	50 complete instrument settings

Physical

Parameter	Value
Power Supply	100 V / 115 V / 120 V / 200 V / 220 V / 240 V AC (±10%), 47 Hz to 440 Hz
Dimensions (W×H×D)	435 mm x 147 mm x 460 mm
Weight	16 kg

Frequency Specifications

Parameter	Value
Frequency Switching Speed	< 15 ms
Internal Reference Frequency	10 MHz
External Reference Input Frequency	10 MHz

Amplitude Specifications

Parameter	Value
Amplitude Resolution	0.1 dB
Output Impedance	50 Ω
Output Voltage SWR	< 1.5 (for output levels <= 0 dBm)

Spectral Purity

Parameter	Value
Harmonics	<-30 dBc (for output levels <= 10 dBm)
Non-Harmonics (Spurious)	<-70 dBc (carrier frequencies > 125 MHz, offset > 10 kHz)
Sub-harmonics	None (for carrier frequencies < 500 MHz), <-40 dBc (for carrier frequencies > 500 MHz)
Residual FM	< 2 Hz (at 500 MHz carrier, 0.3 kHz to 3 kHz bandwidth)
Residual AM	< 0.02% (0.03 to 20 kHz, RMS)
Broadband Noise	<-140 dBc/Hz (at >10 MHz offset from carrier)

Analog Modulation

Parameter	Value
AM Depth Range	0% to 99%
AM Modulation Rate Range	10 Hz to 50 kHz
AM Distortion	< 1% (at 1 kHz rate and 30% modulation depth)
FM Maximum Deviation	Up to 1600 kHz (carrier frequency dependent)
FM Modulation Rate Range	10 Hz to 100 kHz
FM Distortion	< 0.5% (at 1 kHz rate and 40 kHz deviation)
Phase Modulation Rate Range	10 Hz to 20 kHz
Internal Modulation Frequencies	40 Hz, 150 Hz, 300 Hz, 400 Hz, 1 kHz, 3 kHz, 6 kHz, 15 kHz

System Connectivity and Interfaces

Parameter	Value
RF Output Connector	N female (front panel)
External Reference Input Connector	BNC female (rear panel)
Reference Output Connector	BNC female (rear panel)

Physical and Environmental Specifications

Parameter	Value
Operating Temperature Range	0 °C to +55 °C
Storage Temperature Range	-40 °C to +70 °C
Rack Unit Height	3 RU

Power Requirements

Parameter	Value
Power Consumption	Approx. 75 VA

Hardware and Software Options

Parameter	Value
Oven-controlled Crystal Reference Option	SMG-B1 (aging < 1 x 10^-9 / day)
Pulse Modulator Option	SMG-B3
AF Generator Option	SMG-B2 (synthesized internal AF generator)

Protection

Parameter	Value
Overvoltage Protection Max Power	50 W (from 50 Ω source)
Overvoltage Protection Max DC Voltage	35 V

RF Output

Parameter	Value
Level Uncertainty	< 1 dB (for levels > -127 dBm)

Sweep

Parameter	Value
Sweep Spacing	linear or logarithmic

Reference Oscillator

Parameter	Value
External Reference Input Level	0.1 V to 2 V rms
Reference Output Level	approx. 1 V rms (into 50 Ohm)

Technology

RF Analog Signal Generator

Applications

RF transmitter testing, receiver characterization, general laboratory RF testing