An X-Band State Adjustable Low Noise Amplifier Using Current Reuse Technique
, Lixi Wan 2, Zhengli Wang 4, Haitao Zhang 1,2, Yunqian Song 1,2, Xiaobin Zhang 1,2 and Zhi Jin 1,*Round 1
Reviewer 1 Report
This article presents an on-chip state-adjustable 8GHz~12GHz low-noise amplifier (LNA). It has two characteristics. First, an improved current reuse topology is proposed. By connecting a small capacitor in parallel with the drain of the first-stage transistor, the bandwidth is expanded and the in-band flatness is improved.
Comments:
Please explain why S21 is different between simulation and measurement after 10GHz.
There are some typos, please correct them:
on ???、 ??? and ??,
How does the bias circuit work?
What is your novelty? This method was introduced before by other designers. Please explain what is different between your design with other work.
Please report two-tone measurement results.
If figure 9, the effect of the Rs on Gain is high. How can you solve this problem?
I suggest authors to do an English proofreading by a native speaker. It would improve the quality of the paper.
Author Response
Dear Reviewer,
Thank you for your comments, I have answered each of your questions in the attachment, please see the attachment, thank you very much.
Best regards
Author
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper presents a state adjustable low-noise amplifier using current reuse technique. However, I have some comments:
1. The schematic of the current reuse LNA shown in Fig. 1 and Fig. 4 seems to be different, it’s a little confusing. Please clarify this issue.
2. It is hard to identify the impedance as shown in Fig. 5. Please replot the figure instead of just taking the plot from the software.
3. In Fig. 6, the authors present the investigation of effect for the inductance (L1) at first stage. It’s confusing since the parameters that the authors are working with are in um. Please clarify the analysis presented for Fig. 6.
4. In Table 4, the authors are comparing the performance using a figure of merit (FoM). Please include all the parameters for calculation in the table for a clear comparison.
5. The adaptive biasing circuit is not showing an obvious improvement in the temperature coefficient for the small-signal gain. There are some other works reported with better experimental results. Please include them for comparison and discuss the difference.
6. The measured noise figure is good. Please include a measured or simulated minimum noise figure of the device which is adopted for the design. Moreover, please explain how the low noise figure is achieved over a wide operating frequency.
7. Please include the simulated results for P1dB and noise figure in Fig. 14 for comparison. Also, please include the measured stability factor.
Author Response
Dear Reviewer,
Thank you for your comments, I have answered each of your questions in the attachment, please see the attachment, thank you very much.
Best regards
Author
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
It can be published in this version
Reviewer 2 Report
I have no further comments.
