Richard A. Chamberlin

Verification of a foundry-developed transistor model including measurement uncertainty

We verify a foundry model for state-of-the-art 250 nm heterojunction bipolar transistors with large-signal measurements. We demonstrate the propagation of correlated measurement uncertainties through the verification process, and use them to quantify the differences we observe in the measurements and models.

Transistor Model Verification Including Measurement Uncertainty

We verified a model for state-of-the-art 250-nm heterojunction bipolar transistors with large-signal measurements. We demonstrated the propagation of correlated measurement uncertainties through the model extraction and verification processes and used them to quantify the differences observed in the measurements and models and the accuracy of the model parameters we extracted.

650 GHz bistatic scattering measurements on human skin

Many groups are developing submillimeter cameras that will be used to screen human subjects for improvised explosive devices (IEDs) and other threat items hidden beneath their clothing. To interpret submillimeter camera images the scattering properties, specifically the bidirectional scattering distribution function (BSDF) must be known. This problem is not trivial because surfaces of man-made objects and human skin have topographic features comparable to the wavelength of submillimeter radiation—thus simple, theoretical scattering approximations do not apply. To address this problem we built a goniometer instrument to measure the BSDF from skin surfaces of live human subjects illuminated with a beam from a 650 GHz synthesized source. To obtain some multi-spectral information, the instrument was reconfigured with a 160 GHz source. Skin areas sampled are from the hand, interior of the forearm, abdomen, and back. The 650 GHz beam has an approximately Gaussian profile with a FWHM of approximately 1 cm. Instrument characteristics: angular resolution 2.9⍛; noise floor -45 dB/sr; dynamic range ˃ 70 dB; either s or p-polarization; 25⍛ bidirectional-scattering-angle ≤ 180⍛ ; The human scattering target skin area was placed exactly on the goniometer center of rotation with normal angle of incidence to the source beam. Scattering power increased at the higher frequency. This new work enables radiometrically correct models of humans.

Measurement Challenges for 5G and Beyond: An Update from the National Institute of Standards and Technology

In less than a decade since the mainstreaming of cellular wireless technology, spectrum has become saturated by data-intensive smartphones, driving the so-called spectrum crunch. As a solution, the wireless community is pursuing the use of alternatives to current wireless technologies, including multiple-input/multipleoutput (MIMO) antenna arrays that allow increased simultaneous transmission capacity; the millimeter-wave (mmW) spectrum (30-300 GHz) to alleviate the spectrum crunch in current frequency bands; and ultradense networks transmitting wide-band modulated signals to allow short-range, high-speed data transfer.

Measurement and Modeling of Heterogeneous Chip-Scale Interconnections

We present precision scattering-parameter measurements of chip-to-chip connections in heterogeneous integrated circuits: indium phosphide or gallium nitride “chiplets” mounted on Silicon Complementary Metal-Oxide-Semiconductor carrier chips. We demonstrate methodology, experimental results, and modeling results of these chip-scale interconnections from dc to 110 GHz. We used thru-reflect-line on-wafer calibration to establish reference planes inside heterogeneous integrated circuits, and then, we translated those reference planes to the proximity of the chip-to-chip transitions to isolate their contribution to the scattering parameters.

The Role of Measurement Uncertainty in Achieving First-Pass Design Success

We investigate the role of measurement uncertainty in achieving first-pass design success at microwave frequencies. We develop a model for state-of-the-art 250 nm heterojunction bipolar transistors, and demonstrate the propagation of correlated measurement uncertainties through the model-extraction and verification process. We then investigate the accuracy of the extracted model parameters and the role of measurement uncertainty in gauging the ability of the model to predict the behavior of the transistor in large-signal operating states.