Test and Measurement Channel

Rohde & Schwarz SMB100A Signal Generator

Rohde & Schwarz today announced the R&S SMB100A analog signal generator that offers the best combination of performance, ease of use, and serviceability of any instrument in its price range. The R&S SMB100A is an excellent choice for R&D as well as production testing in both commercial and aerospace and defense applications. The R&S SMB100A is the successor to the R&S SML Series that is highly regarded throughout the world, and it is based on the graphically-oriented, Linux-based operating system of the company?s ?high-end? R&S SMA Series instruments. As a result, both configuration and measurement are simple for technicians and veteran designers alike. The R&S SMB100A is available in four models with measurement coverage from 9 kHz to 1.1, 2.2, 3.2 and 6 GHz. Within the ?midrange? class of analog signal generators, it delivers higher output (+18 dBm specified and +25 dBm in overrange mode) with greater flatness (+/- 0.5 dB < 3GHz, +/- 0.9 dB > 3GHz), faster setting time (less than 3 ms for frequency, less than 2.5 ms for level, and less than 1 ms in list mode), and lower phase noise. At 1 GHz with a 1 Hz measurement bandwidth, phase noise is typically -128 dBc/Hz at a 20 kHz carrier offset. Unlike competitive instruments that employ mixers to cover the lowest frequencies in their output range, the SMB100A employs a direct digital synthesizer (DDS) from 9 kHz to 23.3475 MHz. This dramatically improves phase noise performance at low frequencies. The mixing approach typically degrades phase noise performance in the mixing range, while phase noise of the R&S SMB100A remains low, with little variation, all the way to its lowest output frequency. This makes the instrument an excellent choice for use as a crystal oscillator replacement and other low-frequency signal generation applications as well. The high performance and versatility of the SMB100A make it well suited for both general-purpose benchtop applications and the production line. When used in the development of mixed-signal circuits for example, the non-harmonic suppression and wideband noise performance of a signal generator are key parameters. The SMB100A easily satisfies these requirements with the highest level of nonharmonic suppression in its class (-70 dBc at 1 GHz at a 10-kHz offset). ?Wideband noise is typically -152 dBc at 1 GHz as well. High-volume production test applications demand the highest levels of measurement speed, since even small decreases in frequency and level setting times, multiplied by the large number of products tested over a given time, can significantly improve throughput and reduce manufacturing cost. The extremely fast frequency and level setting times of the R&S SMB100A along with its standard Ethernet and IEEE-488 connectivity make it extremely well suited for these environments. In list mode, up to 2000 pairs of frequency and level can be stored in the instrument and run automatically, reducing setting time to less than 1 ms, the highest speed in its class. Production test and other ATE applications also incur considerable signal losses caused by the many cables and connectors required. The high output level of the R&S SMB100A compensates for these losses, typically eliminating the need for an external power amplifier to boost RF output. The R&S SMB100A is also designed to be serviced on-site by the owner thanks to an architecture that relies on only four main modules. A self-diagnostic routine checks the modules, and if servicing is required a module can be replaced on site. Backups for any of the four modules can be retained in inventory, and each one is calibrated at the factory. In addition, precise level adjustment and correction can be performed after the repair is completed by simply connecting a Rohde & Schwarz NRP power sensor to the instrument. As a result, the instrument can return to service with a minimum of downtime. Calibration interval for the R&S SMB100A is 3 years. The R&S SMB100A meets the needs of aerospace and defense applications such as radar system (pulsed signal) testing. In addition to the instrument?s standard AM, FM, and phase modulation, a pulse generator and pulse modulator are available as options. The pulse modulator has a typical on/off ratio of 90 dB and rise and fall times of 10 ns. The flexible pulse generator has a minimum pulse width of 20 ns, which allows it to generate a wide variety of pulsed signals. The instrument operates over a temperature range of 0o C to +55o C at a maximum altitude of 4600 m, weighs only 5.3 kg (11.7 lb), and requires only two height units in a rack. All are essential attributes when measurements must be made in airborne, mobile, and other environmentally or physically challenging situations. The instrument will also soon be offered with the ability to perform a dedicated clearance procedure so that nothing can be recovered if the instrument falls into unfriendly hands. Other features of the R&S SMB100A include reverse power protection of 50 W at 1 GHz, 25 W up to 2 GHz, and 10 W at 6 GHz, broadband frequency modulation with a maximum deviation of 16 MHz above 3 GHz, VSWR of less than 1.8:1, measurement repeatability of +/-0.02 dB, integrated frequency, level, and low-frequency sweeps, and an internal low-frequency generator that delivers sine wave signals up to 1 MHz and square wave signals up to 20 kHz. All models of the R&S SMB100A are available now from Rohde & Schwarz. and are priced from $6,350.

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