The manuscript presents a reconfigurable arbitrary waveform generator (RAWG) that exploits the pulse-width modulation (PWM) technique implemented in a low-cost FPGA for independent control of multiple transmission parameters. The idea is to use it on ultrasound laboratory researches.

My main concern is that the performance was evaluated using RC loads, so no initial tests in a real scenario has been done yet. So authors should elaborate a little bit more on what should be expected when the system has a real transducer load.

The manuscript evokes references 21 and 22, but reference 22 is not in English so the utility will be limited to people that understand that language. Additionally, when published there is no evidence that this reference will be available to the public. Authors should find a solution for that.

References 21 and 22 should be checked regarding the authors’ names are provided. The authors of the manuscript are the same of those references and “Eduardo” and “Joaquim” are their given names and not their family names.

Pg 1, “methods, line 4: change “for independent control of” to “for independent controlling of”.

Pg 4, line 6: change “handling a large among of” to “handling a large amount of”.

Pg 4, line 20: change “can be independently drive to each” to “can be independently driven to each”.

Pg 5, lines 1-2: “…as well as a good penetration depth to increase the image quality fully”. What do you mean by "fully"? Image quality depends on other aspects too.

Pg 6, “Results”, 3rd paragraph: “The maximum output frequency that the RAWG is capable of generating is 20 MHz and a slight decrease in the output amplitude over the 10 MHz to 20 MHz can be noted.”. According to figures 7a and b, there is around 20% of voltage loss, I would not call it a "slight decrease".

Pg 6, last paragraph: change “four different 20 MHz…” to “four different 20-MHz…”.

Pg 6, last paragraph: change “… radiation patterns” to “… radiation pattern”.

Pg. 6, Results, 3rd paragraph: change “Figures 7(a) and 7(b) allows” to “Figures 7(a) and 7(b) allow”.

Pg 7, lines 1-2: “Figure 8(c) shows a medium bandwidth pulse with a relative bandwidth of 54.2 %, which is appropriate for detection and sizing,…”. Detection and sizing of what? Please be more specific.

Pg. 7, lines 3-4: “A narrow bandwidth pattern used for detection of interfaces between media of different acoustic impedance with…”. All those pulses are capable of detecting interfaces of media with different acoustic impedances. So why this observation only for Figure 8c? They can also be used for detection and sizing.

Pg 7, line 6: change “can produces” to “can produce”.

Pg 7, line 8: change “the second harmonic of the produced pulses were” to “the second harmonic of the produced pulses was”.

Pg 7, 2nd paragraph: “Figure 9 shows the experimental resulting eight waveforms generated simultaneously…”. If there is a delay in the generation then it is not simultaneous, please rewrite the sentence.

Pg 7, Discussion, lines 2-3: “to generate high voltage output waveforms…”. You mean "high voltage" considering the intended application...It is important to give a complete idea of what you mean, given that potential readers of Biomedical Engineering area have different backgrounds.

Pg 7, Discussion, 3rd paragraph: “…our preliminary experimental results show that the proposed research platform can be considerably advantageous to provide accurate control over several US transmission parameters, such as waveforms, aperture weighting amplitude control and dynamic focusing phase adjustment.”. It would be useful to give some data and/or characteristics regarding other platforms (as the ones you mentioned in the Background section) and compare with the one you present here, so readers can evaluate if it is really "considerably advantageous" as you state.

Pg 7, Discussion, 3rd paragraph: change “The proposed architecture was evaluated across onboard” to “The proposed architecture was evaluated through onboard”.

Pg. 8, line 11: change “there was a output” to “there was an output”.

Discussion section: In the objective you mention "low-cost" I would like to see more comments on that.

The expression “preliminary results” (that appears in the abstract and in the conclusion) should be change “preliminary experimental results” or something like that the testes were performed only with RC loads.

English revision is recommended.

Conflicts of interest

Do you have any conflicts of interest here? NO