Temperature Reliability Investigation for a 400 W Solid-State Power Amplifier under High and Cold Conditions
Philip Moore
Round 1
Reviewer 1 Report
This paper presents research designed to address a perceived issue around temperature for radio frequency power amplifiers which the authors identify as a potential issue. I have comments:
1) The title, abstract and keywords need revision to remove acronyms which must be restricted to the main body text of the manuscript.
2) The introduction must be completely rewritten because it is currently a conflation of an introduction and a review of relared research (a literature review). The current introduction muct be revised in two dedicated sections: (a) Introduction: setting out the backgrounf and motivation for the research, a brief overview of the study, (c) the claimed contribution made by this study, and the paper structure, and (b) Releted Research: a literature review considering the related literature along with a comprehensive comparative analysis.
3) The English grammar requires careful proof checking - this is mainly related to the definite and indefinite article but carefulr general proof reading is needed.
4) The figure captions would benefit from a more detailed and comprehensive caption.
5) Thr paper lacks a suitable discussion section, required.
6) The authors vave presented their study but I failed to find any significant consideration of the practical managerial significance (PMS) related to their findings. I noted the comment in the conclusions: "This research provides valuable guidance for reliability design of solid-state PA module". However, it is not clear (at least to me) why the information presented is interesting, useful, and applicable from a PMS perspective?
In summary, this paper is relatively specialised and the application and utility of the results remains unclear. Therefore major revisions to the manuscript are required to inform the study as it relates to the PMS.
The English grammar requires careful proof reading (arguably by a native English speaker) to correct errors. For example: "This research provides valuable guidance for reliability design of solid-state PA module" (should be either 'a solid-state PA module" or "solid-state PA modules". The errors lie in the use of the definite or indefinite article and pluralisation.
Author Response
look at the attachment!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors investigated the performance of the LDMOS 400W power amplifier under various temperature conditions. The manuscript discusses the trends in output power, gain, and power efficiency under different experimental conditions. While the manuscript is well-structured and well-written, there are specific issues that need attention and revision.
1. Please ensure that all acronyms are defined the first time they are introduced in the main text.
2. Could you clarify the meaning of "power additional efficiency"? Did you mean "power-added efficiency"?
3. It is essential to provide more detailed information about the experimental setup. For instance, the temperature chamber is a critical component of the test. Can you specify the temperature range that the chamber can maintain? How accurately can the chamber control and set the temperature? What is the allowed temperature deviation within the temperature chamber?
4. In Figures 7 to 10, it appears that there might be an issue with the right y-axis.
5. In Figure 9, there seems to be a discrepancy regarding the frequency. The figure indicates 30 MHz, while the main text mentions 32 MHz.
Author Response
look at the response letter at the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The use of power amplifiers at extremely low temperatures is an urgent task due to the need for their use in aerospace, aviation, meteorological, radar, navigation, and military practice. On the one hand, lowering the temperature should improve the cooling of heated components. On the other hand, at lowering the temperature the mobility and concentration of charge carriers in semiconductors decreases, which leads to the degradation of power amplifier parameters. Therefore, the relevance of this work is beyond doubt.
In the introductory part, the authors have made a rather in-depth literature analysis on the mentioned topic, which includes 13 references.
The second section describes the block diagram, features, and the principle of the LDMOS 400W Power Amplifier. The authors showed the quiescent working conditions of BHF1D4D (VGS=2.75V, VDS=28V, and IDQ=900mA), and the working conditions of BHF0D2W12D (VDS = 48V and IDQ = 200mA) LDMOS power transistors, which I think is quite correct.
The third and fourth sections are devoted to the presentation of the results obtained. The research methodology used by the authors is correct, so the results obtained are not questionable. However, the results obtained are quite predictable, and when the temperature changes from -39.2℃ to 55℃, all the investigated parameters change almost linearly and without any special anomalies, as one would expect.
In the fifth section, in which the conclusions of the paper are formulated, it is shown that the degradation and inversion of Power Amplifier operating parameters are closely related to the zero-temperature coefficient and self-heating effect of LDMOSFETs. I don't think it's the temperature dependencies of the active semiconductor components that matter so much as the characteristics of the amplifier as a whole. Of course, the selected operating modes of transistors, and the temperature behavior of some passive components also matter, so, in my opinion, similar studies are needed in each specific case, and it would not be quite correct to generalize the data obtained by the authors.
The overall impression of the article is quite positive. The work is written correctly, and the results obtained are of some interest to specialists in this field.
In this article, I found only 3 self-citations by the authors, with a total of 19 citations of about 15%. I believe that this is quite acceptable. The last two references are numbered twice at number 18.
Based on the above, I believe that this article can be published in its present form.
Author Response
look at the response letter in the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I have read the authors resopnse letter and the revised manuscript. There are a number of comments in my original review which I have checked against the revisions:
1) There are still acronyms in the abstract
2) The Introduction is not suitably revised as noted in my review
3) There is still no discussion
4) There is no suitable discussion on practical mangerial significance.
The comments made in my previous review have not been seriously considered or addressed in the revised manuscript. Accordingly, my previous judgement remains and the paper is still not in a suitable condition for publication.
Careful proof reading (by a native English speaker) is required.
Author Response
see the attachment
Author Response File: Author Response.pdf
