Experiences with non-intrusive sensors for RF built-in test

Abstract

ISBN 978-1-4673-1594-4International audienceThis paper discusses a new type of sensors to enable a built-in test in RF circuits. The proposed sensors provide DC or low-frequency measurements, thus they can reduce drastically the testing cost. Their key characteristic is that they are nonintrusive, e.g. they are not connected electrically to the RF circuit. Thus, the performances of the RF circuit are unaffected by the monitoring operation. The sensors function as process monitors and share the same environment with the RF circuit. The underlying principle is that the sensors and the RF circuit are subject to the same process variations, thus shifts in the performances of the RF circuit can be inferred implicitly by shifts in the outputs of the sensors. We present experimental results on fabricated samples that include an LNA with embedded sensors. The samples are collected from different sites of a wafer such that they exhibit process variations. We demonstrate that the performances of the RF circuit can be predicted with sufficient accuracy through the sensors by employing the alternate test paradigm

Solutions for the self-adaptation of communicating systems in operation

“…transistor, capacitor ,resistor, etc.) that can be identified in the topology of the circuit [7]. Fig.…”

Parametric Built-In Test for 65nm RF LNA Using Non-Intrusive Variation-Aware Sensors

“…To this end, it has been proposed to rely on non-intrusive built-in sensors that have the comparative advantage that let the design intact [1,2]. These non-intrusive sensors capitalize on the undesired phenomenon of process variations.…”

“…This type of non-intrusive built-in test based on variationaware sensors was demonstrated for a 0.25μm RF LNA in [2]. A disadvantage of the technique, as we explain in more detail later on, is that the correlation between the sensor measurements and the performances of the CUT and, ultimately, the success of alternate test, is affected by uncorrelated WID variations (e.g.…”

“…However, adding a dummy inductor PCM is not a smart choice since it incurs a large area overhead. For this reason, variability in the inductors was not considered at all in [2]. In this work, we studied the sources of variability in the inductors and we found that most of the variability is due to the variability in the resistivity of the high-level metal and alucap layers that form the coils of the inductors and not due to the variability in the pure inductance of the coil.…”

True non-intrusive sensors for RF built-in test

“…Especially for RF circuits this objective is hard to satisfy since these circuits are very sensitive and tapping into their signal paths may seriously unbalance the performance trade-offs achieved by design. For example, loop-back test for transceivers [6], [7], [8], [9], where the test signals are generated in the baseband and the transmitter's output is connected to the receiver's input This paper is an invited summary paper on the Ph.D. dissertation work of Louay Abdallah [I] that was earried out at TIMA Laboratory (CNRSGrenoble INP -UJF), Grenoble, Franee, from Oetober 2008 to Oetober 2012 under the supervision of Haralampos-G. Stratigopoulos and Salvador Mir: Parts of this summary paper have been previously published in [2] , [3], [4] , [5]. This summary paper was invited in the framework of the finals of the 2013 IEEE Computer Soeiety Test Teehnology Teehnieal Couneil (TTTC) doetoral thesis award competition that took plaee at the 20 to analyze the test response also in the baseband, requires the insertion of a switch and an attenuator to perform the connection and, for some types of transceivers, even an extra mixer is inserted in the RF signal path.…”