A Wireless Data Transfer by Using a Patch Antenna for Biomedical Applications
Round 1
Reviewer 1 Report
The authors have presented a wireless data transfer (WDT) system with a notch-based biomedical patch antenna that operates at 20 GHz frequency. The results of the proposed antenna show wider bandwidth and higher radiation gain as compared to the traditional patch antenna. Additionally, the manuscript shows how the power consumption of the WDT system can be significantly reduced by using NTV oscillator. There are a few comments for the authors as listed below:
1. It is impressive that a smaller antenna provides good bandwidth and gain at 20GHz frequency. Since this is shown to be applicable for in-brain WDT chip, does it comply with the FCC guidelines? If yes, please add a reference stating that.
2. Please explain, why the inside antenna design in the wireless biotelemetry system (Fig. 7) is kept different from the outside antenna design? How will the results differ if both inside and outside antennas are same?
3. In the simulation scenario, the authors have introduced different tissue layers inside the brain, i.e., Brain/skull, fat, and skin. However, there is another layer that exists below the skin, which is periosteum tissue layer. This is the membrane of blood vessels and nerves that wraps around the skull. It is well known that any tissue that has higher water content is very conducive at such high frequencies. Therefore, it is important to consider this layer in the simulations as well to have a better understanding of how this biotelemetry device will work in this conductive environment. Otherwise, the results with only fat layer between the skull and skin is not very practical.
4. Please specify the frequency at which the permittivity values in Table 1 are collected.
5. In Fig. 9, the effect of simulated S21 frequency characteristics at different antenna gap distance is presented. Please specify in Fig. 7, which gap is being considered here.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
Thanks for your questions.
We are careful in responding to your questions.
Please see the attachment file.
Thank you one again!
Gyungsu Byun (Prof., Dr)
Author Response File: Author Response.pdf
Reviewer 2 Report
Authors have presented a wireless data transfer by using a patch antenna for biomedical applications at 20GHz. Following comments would be helpful to improve the paper and to highlight the significance of the work.
Usually, the implants are communicating at much lower frequencies as mentioned by authors in introduction i.e. MICS or ISM band and some work is also reported at higher frequencies. Why authors have chosen 20GHz and what band will be used. Add references and highlight applications for this frequency band.
Add work from literature carried out on 20GHz implants.
The dielectric properties of the human tissue layers are presented in table 1, mention the frequency in caption of Table 1 at which these properties are listed.
Add Specific Absorption Rate (SAR) results and add relevant discussion.
The comparison presented in Table 2 is not fair due to large differences in operating frequencies. Add some references at 20GHz and compare (if any available). Also, present the dimensions and the bandwidth in terms of wavelength for better comparison.
Author Response
Dear Reviewer,
Thanks for your questions.
We are careful in responding to your questions.
Please see the attachment file.
Thank you one again!
Gyungsu Byun (Prof., Dr)
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thanks for your revision, I have no further comments.
Reviewer 2 Report
Authors have addressed reviewer's comments and manuscript has been improved.
