3 research outputs found
Output Power and Gain Monitoring in RF CMOS Class A Power Amplifiers by Thermal Imaging
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The viability of using off-chip single-shot
imaging techniques for local thermal testing in integrated
Radio Frequency (RF) power amplifiers (PA’s) is analyzed.
With this approach, the frequency response of the output
power and power gain of a Class A RF PA is measured, also
deriving information about the intrinsic operation of its
transistors. To carry out this case study, the PA is
heterodynally driven, and its electrical behavior is down
converted into a lower frequency thermal field acquirable
with an InfraRed Lock-In Thermography (IR-LIT) system.
After discussing the theory, the feasibility of the proposed
approach is demonstrated and assessed with thermal
sensors monolithically integrated in the PA. As crucial
advantages to RF-testing, this local approach is noninvasive
and demands less complex instrumentation than
the mainstream commercially available solutions.Peer ReviewedPostprint (author's final draft
Differential temperature sensors: Review of applications in the test and characterization of circuits, usage and design methodology
Differential temperature sensors can be placed in integrated circuits to extract a signature ofthe power dissipated by the adjacent circuit blocks built in the same silicon die. This review paper firstdiscusses the singularity that differential temperature sensors provide with respect to other sensortopologies, with circuit monitoring being their main application. The paper focuses on the monitoringof radio-frequency analog circuits. The strategies to extract the power signature of the monitoredcircuit are reviewed, and a list of application examples in the domain of test and characterizationis provided. As a practical example, we elaborate the design methodology to conceive, step bystep, a differential temperature sensor to monitor the aging degradation in a class-A linear poweramplifier working in the 2.4 GHz Industrial Scientific Medical—ISM—band. It is discussed how,for this particular application, a sensor with a temperature resolution of 0.02 K and a high dynamicrange is required. A circuit solution for this objective is proposed, as well as recommendations for thedimensions and location of the devices that form the temperature sensor. The paper concludes with adescription of a simple procedure to monitor time variability.Postprint (published version
Survey of robustness enhancement techniques for wireless systems-on-a-chip and study of temperature as observable for process variations
Built-in test and on-chip calibration features are becoming essential for reliable wireless connectivity of next generation devices suffering from increasing process
variations in CMOS technologies. This paper contains an overview of contemporary self-test and performance enhancement
strategies for single-chip transceivers. In general, a trend has emerged to combine several techniques involving process variability monitoring, digital calibration,
and tuning of analog circuits. Special attention is directed towards the investigation of temperature as an observable
for process variations, given that thermal coupling through the silicon substrate has recently been demonstrated as mechanism to monitor the performances of analog circuits.
Both Monte Carlo simulations and experimental results are presented in this paper to show that circuit-level specifications exhibit correlations with silicon surface temperature changes. Since temperature changes can be measured with
efficient on-chip differential temperature sensors, a conceptual outline is given for the use of temperature sensors as
alternative process variation monitors.Peer Reviewe