Circuit Analysis & Design Contest


 IEEE SSCS International Student Circuit Contest 

Submission Deadline: January 15, 2020 - EXTENDED DEADLINE

The IEEE Solid-State Circuits Society is pleased to announce it’s second annual student circuit contest. The objective of this contest is to engage students in thought-provoking circuit analysis and design problems. Submissions are solicited by both undergraduate and graduate students who are currently enrolled in a college or university.



This contest involves a feedback amplifier that at first glance seems to be unstable, but is perfectly stable. We are asking for your intuitive explanation of this situation.


Consider the feedback amplifier shown below:


where the open loop amplifier A(s) is given by:


contest2019 2



If we investigate the Bode plot of the loop gain, we can confirm that at contest2019 3 (that is the angular frequency at which the phase of the loop gain reaches -180 degrees), the magnitude of the loop gain is much greater than 1 (in fact it is 36dB). We may naturally conclude that this feedback amplifier is unstable, simply because a signal at contest2019 3must grow out of bound as it goes around the loop. Yet, when we use the Nyquist plot, we find that this system is indeed stable.

We are reaching out to you, as an SSCS student member, to provide your intuitive reasoning for why this is the case. Please limit your intuitive explanations to a maximum of two pages.


Please note that we are NOT asking for proof of stability of this system; we know that the system is indeed stable using Nyquist Stability criterion. What we are asking is an intuitive explanation of why the intuition given above (using Bode Plot and loop gain) is incorrect!




Up to three contestants with best answers will receive US$2K each towards attending an SSCS-sponsored conference (ISSCC, CICC, ESSCIRC, VLSI Symp., ASSC). This award is paid either as a reimbursement following the attended conference or will be paid directly to the conference for registration and to the hotel for accommodations. All the submitters with the right answers will receive one year of free membership in the Solid-State Circuits Society, and their names will be highlighted in the Solid-State Circuits Magazine.


Rules and Regulations

Please be sure to read the contest guidelines, rules, and regulations - click here to access. 


Submission Guidelines

All submissions must be submitted by a form - click here to access

The submission deadline is January 15, 2020 - EXTENDED DEADLINE

If you do not follow these instructions, your submission will not be accepted. 


You must be an IEEE Student or Graduate Student Member in 2019 and/or 2020 in order to be eligible for the contest. 


If you have any questions, please email