The device has two independent channels that can tune in 0.1 Hz increments from 54 MHz to 13.6 GHz. The SynthHD’s RF power is adjustable in .01 dB increments from -50 dBm to +22 dBm. It also has many modulation features including FM chirps. The relative phase between the two channels can be adjusted in .01 degree increments. It is a hybrid approach because the device can either be controlled with a PC graphical user interface (GUI) like benchtop test and measurement (T&M) equipment, or it can be programmed to function as a module inside a communication system without a PC, like the narrow band synthesizer mentioned above.
The GUI is laid out as close as possible to similar bench top signal generators. After tuning to the spec needed in the project, those settings can then be programmed to the SynthHD signal generator’s nonvolatile memory. The device will power up that way from now on, with sweeps or modulation, even both. Another interesting feature with all of Windfreak Technologies software is that it is written in Labview, and the software source code is included with the purchase. Labview is ubiquitous for controlling test equipment in labs all around the world. This allows the end user to hack out the features they don’t need, or add features they do need for ease of use. The SynthHD is really the best of both worlds. Its RF power settings can be calibrated for accuracy. It has an external reference input or output for frequency stability, an external trigger for stepping and other functions like external modulation, and a GUI for quickly adjusting parameters similar to their benchtop counterpart. To make it even more accurate, there is an onboard temperature compensation algorithm that periodically makes amplitude adjustments over temperature.
Module integration engineers get much more tuneability than they were going to get with the old solution. This allows them to purchase one broadband device for their system instead of many narrowband variations. They don’t have to use external attenuators to perfectly set the RF power. The SynthHD also has an ultra-small form factor with mounting tabs. Similar Windfreak designs have successfully flown on fighter aircraft—suggesting sufficient ruggedness for most applications. The SynthHD signal generator is not just a continuous wave (CW) generator. It can also sweep, hop and modulate.
The SynthHD signal generator will generate sweeps. The sweeps can be single channel or dual channel. The device can sweep up or sweep down. It can also ramp up or down amplitude while sweeping. The sweep can be controlled with an external trigger to either perform a full sweep per trigger, or perform a single step. In dual channel mode you can program a constant frequency offset between the two channels for the sweep.
The SynthHD signal generator will generate hops. The GUI allows the user to program up to 100 arbitrary points with a frequency and amplitude in dBm. This table is stored onboard in nonvolatile memory. Like the sweep mode the user can then have an offset on the other RF channel, hop up the list, hop down the list, and work with the trigger input.
Additionally, the SynthHD signal generator will digitally modulate FM, AM, and pulse. FM can be a typical sinusoidal signal, or it can also be a chirp. AM can also be the typical sinusoid signal or it can be ramps. The modulations can be combined. Combining a pulse and a chirp allows the user to set up a frequency modulated continuous wave (FMCW) radar signal. You can even combine this with the sweep function. As an electronic warfare example, you could sweep a pulsed waveform across a range of frequencies. Rates can be very slow, or in the case of FM, up to 5 KHz. Of course, all of these features can be saved to the device; it will begin sweeping on power up without a PC connected!
Use the external Trigger connection to perform external modulation such as FM, AM and Pulse.