R&S®SMF100A Microwave Signal Generator

The R&S^®SMF100A (22 or 43.5 GHz model) in combination with one of the below frequeny multipliers R&S^®SMZ covers the frequency range from 50 GHz up to 170 GHz

For generating more complex pulse scenarios, the R&S^®SMF100A offers a new feature – based on its pulse modulator and pulse generator concept – using the R&S^®SMF-K27 pulse train option. In contrast to single or double pulses, "pulse trains" are a combination of different pulses, which can be a periodical or non-periodical set of pulses. The built-in optional pulse generator makes it now possible to generate these "pulse trains", which are commonly used for radar applications. Pulse width as well as pulse pause can be set independently and separately for each pulse. This makes it possible to generate staggered pulses or to apply jitter to pulse width as well as pulse pause.

In contrast to ARB solutions, the greatest advantage is the much better performance of the pulse modulator with respect to ON/OFF ratio, rise and fall time, etc.

In the absence of spectrum or network analyzers scalar network analysis can be performed by means of the R&S^®SMF100A microwave signal generator with the R&S^®SMF-K28 power analysis option plus an R&S^®NRP-Zx power sensor. One example is to measure the passband characteristic of a bandpass filter.

The input of this filter is connected to the RF output whereas the output is connected to an R&S^®NRP-Zx power sensor. The power sensor itself is plugged to the sensor input of the R&S^®SMF100A. Based on the entered frequency range the R&S^®SMF100A performs the measurement and displays the passband of this bandpass filter. The filter can now be manually tuned and the adjustments can be directly controlled on the R&S^®SMF100A display.

Measurement setup:

For enabling the power analysis the option R&S^®SMF-K28 is needed.

Compression point analysis with an R&S^®NRP-Zxx power sensor.

The R&S^®SMF100A microwave signal generator plus a power sensor R&S^®NRP-Zxx enables pulse data analysis in measurement mode “power”. In the following graphs 1 dB- and 3 dB-compression point measurements of an external amplifier are shown:

Measurement setup:

Measurement setup:

For enabling the power analysis the option R&S^®SMF-K28 is needed.

Pulse analysis with an R&S^®NRP-Zxx power sensor.

The R&S^®SMF100A microwave signal generator in combination with a power sensor R&S^®NRP-Z81 enables pulse data analysis in measurement mode “time”. All important pulse parameters are measured after setting the threshold levels. The following graph shows most of these parameters:

Measurement setup:

For enabling the power analysis the option R&S^®SMF-K28 is needed.

DUTs such as power amplifiers always have frequency responses. In these cases, the signal generator needs to compensate for the frequency response. The R&S^®SMF100A offers the User Correction function for precisely this purpose. For a known frequency response that needs to be corrected, you can enter the level correction values as a function of the frequency. Automatic interpolation of the correction values is performed between these frequency points.

To simplify this, the R&S^®SMF100A can also automatically include the level correction values at the press of a button by using external Rohde & Schwarz power sensors.

One important performance requirement in many applications is the generation of a highly accurate and stable power for testing DUTs (e.g. power amplifiers). This is not a trivial task since the real power directly applied to the DUT is affected by the level accuracy of the signal generator, the losses due to cables, the losses due to modules or components or the gain of an amplifier and last but not least by mismatching (as illustrated below).

The solution to overcome the above problem is “closed loop power control” in real time which is a standard feature of the R&S^®SMF100A or R&S^®SMB100A. In the below setups it ensures a highly accurate and very stable input power to the DUT irrespective of unwanted power drifts or changes in your setup.

In between the RF output of the R&S^®SMF100A or R&S^®SMB100A and a directional coupler (or the R&S^®NRP-Z28) different components, modules, amplifiers or cables might be used, which lead to a unknown input power to the DUT. By using the R&S^®NRP-Zxx power sensor connected to the directional coupler or the R&S^®NRP-Z28 instead, one can measure the input power to the DUT. The measurement result of the R&S^®NRP-Zxx or the R&S^®NRP-Z28 is fed back to the R&S^®SMF100A or R&S^®SMB100A which compares the measured level with the wanted level. It immediately adapts its output power in order to overcome the discrepancy between wanted and measured level.