Design of an Analog RFID-Based Tag Antenna with Opened Circuited L-Shaped Stubs for Applications in Localization

Round 1

Reviewer 1 Report

The paper is focused on proposing an antenna for RFID tags with increased working distance.

Stylistic proposals/comments:

26 line: should be "stub structures", not "stubs structures"
35 line: should be minus sign
86 line: figure 1 should have a captal "F"
line 122: equation should be numbered and dot should be at the end.
3.1 section - capacity should be changed to capacitance.
Figure 3 a: don't really see the point of having red and yellow bar (-20 and 20 pF), these capacitance values are not seen
159 line: don't see the reason of writing "'" at "stub'"
217 line: "varies" has a different font...
Figure 15 should be narrowed
The figures should have a similar font size, ex. Figure 11 and Figure 12 have a different font size on the axis. This must be corrected. 
English and formatting should be heavily reviewed...

General questions/comments:

- Table 1 - it would be a good idea to mention the topologies of the listed antennas, maybe the topology is the same, but there are slight differences, or they are very different
- Figure 5 - what is the reason of introducing the gaps and stubs on the edges of the antenna structure (fig. 5 b)? Why are the gaps and stubs asymmetric (the bottom stub is single, the top one is double)? The design topology and the solutions applied have to be explained. 
- In the conclusions, line 369 states that if an industrial chip has an output impedance of 16-j194 (Ω), the S11 is -22.3dB. Is there any impedance matching network in between the antenna and the transmitter? 16-j194 and 50Ω is quite a large mismatch. More details on the testbench must be included in the experimental part and mentioned in the conclusions.

I'd suggest that major changes are required before accepting.

Author Response

Please find the response file

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper proposed a UHF dual-band tag antenna for localization applications. The following issues should be addressed before aceept. 

1. Some recently publised literatures should be cited in the introduction. 

2. Section 2 should be condensed. 

3. It would be better if the authors remove Refs. [16], [18]-[21] from Table 1, and add some recently publised literatures for comparison. 

4. Please give a discussion on the application scenario of the proposed antenna, e.g., 10.3390/s21093286, 10.3390/s19235125.

Author Response

Please find the response file, thanks

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The comments/proposals have been addressed.

Author Response

Thanks for the acknowledgment.