Rohde & Schwarz SMR Microwave Signal Generators

The Rohde & Schwarz SMR series is built around a standardized architecture featuring a backlit monochrome LCD and internal storage capable of saving up to 50 complete instrument setups. For system integration and automated testing, the platforms include standard remote interfaces. The Rohde & Schwarz SMR27 provides both GPIB (IEEE-488) and RS-232 interfaces, whereas the Rohde & Schwarz SMR40 provides a GPIB (IEEE 488.2) interface.

All instruments in the series utilize a standard 10 MHz TCXO reference oscillator with an aging rate of less than 1 x 10^-6 per year. To achieve higher frequency stability, the optional OCXO (Option SMR-B1) can be integrated, which improves the aging rate to less than 5 x 10^-10 per day. The warm-up time of the instrument is approximately 10 minutes when using the standard TCXO, and approximately 30 minutes when equipped with the optional OCXO SMR-B1.

Model selection in the SMR family is primarily determined by the target frequency band and required spectral purity:

• Rohde & Schwarz SMR20: Serves as a CW generator covering 10 MHz to 20 GHz (with a minimum frequency of 1000000000 Hz in standard configurations).
• Rohde & Schwarz SMR27: Covers a frequency range from 10 MHz to 27 GHz. It provides a standard frequency resolution of 1 kHz, which can be refined to 0.1 Hz via the optional R&S SMR-B3. Phase noise is specified at <-83 dBc/Hz (typical -89 dBc/Hz) at a 10 kHz offset with a 10 GHz carrier.
• Rohde & Schwarz SMR40: Offers the highest frequency coverage in the family, spanning 10 MHz to 40 GHz. It features a standard frequency resolution of 1 kHz (upgradeable to 0.1 Hz via option SMR-B9) and delivers a phase noise of <-103 dBc/Hz (typical -109 dBc/Hz) at a 10 kHz offset and 10 GHz carrier. Both the SMR27 and SMR40 offer a frequency settling or switching speed of less than 10 ms.

Standard models deliver digital frequency sweeps, level sweeps, and pulse modulation. Additional optional configurations allow users to extend the capabilities of each instrument:

• Rohde & Schwarz SMR27: Offers a standard output power range of -20 dBm to +11 dBm (for frequencies up to 20 GHz) and up to +9 dBm (for frequencies above 20 GHz). Installing the optional R&S SMR-B9 step attenuator extends this range down to -130 dBm.
• Rohde & Schwarz SMR40: Features a standard output power range of -20 dBm to +9 dBm. Users can extend this range down to -130 dBm using the optional SMR-B17 step attenuator.
• Modulation and Sweep Upgrades: For both the Rohde & Schwarz SMR27 and Rohde & Schwarz SMR40, AM, FM, and phase modulation can be added using the optional SMR-B5 (or R&S SMR-B5) module. To enable analog ramp sweeps in place of standard digital sweeps, the SMR-B4 (or R&S SMR-B4) option must be installed.