C. De Martino
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23 records found
1
Meeting these requirements using the currently allocated microwave spectrum has become challenging due to limited available bandwidth and the physical constraints associated with longer wavelengths. Consequently, both research and, more recently, commercial applications have been shifting toward higher-frequency spectrum ranges, where wider bandwidths and shorter wavelengths can be exploited. To support this transition, numerous studies have been published in recent years, documenting significant progress in the electronic device development cycle. Nevertheless, despite these advances, several areas still require improvement. This thesis addresses some of the persistent limitations in the measurement and characterization of electronic devices (both before and after fabrication) where the community continues to rely on low-frequency methods, techniques, or data extrapolated from lower frequencies and applied at higher frequencies.... ...
Meeting these requirements using the currently allocated microwave spectrum has become challenging due to limited available bandwidth and the physical constraints associated with longer wavelengths. Consequently, both research and, more recently, commercial applications have been shifting toward higher-frequency spectrum ranges, where wider bandwidths and shorter wavelengths can be exploited. To support this transition, numerous studies have been published in recent years, documenting significant progress in the electronic device development cycle. Nevertheless, despite these advances, several areas still require improvement. This thesis addresses some of the persistent limitations in the measurement and characterization of electronic devices (both before and after fabrication) where the community continues to rely on low-frequency methods, techniques, or data extrapolated from lower frequencies and applied at higher frequencies....
This work presents a structured, CAD-assisted design flow to realize broadband on-wafer calibration structures, validated in the prefabrication phase, and extract the intrinsic device response up to (sub)mm-waves. The strict requirements imposed by the design rule checks (DRCs) of 22 nm CMOS technology are incorporated during the design phase of the fixture by using a scripted connectable tile elements approach. The minimum dimension of a critical feature of the fixture is then identified using a newly defined metric based on the correspondence between the EM field distribution in the fixture versus a non-perturbed case of the same standard (STD) artifact. A simulation test bench environment, augmented with experimental data, is then used to add the uncertainties arising from three main error contributors: vector network analyzer (VNA) receiver noise, probe placement error, and calibration residual errors. Including these errors allows for the generation of pre-silicon numerical uncertainty bounds, which are benchmarked with experimental data using calibration quality metrics and device-level parameters. Measurement results ranging from 1 to 325 GHz are presented to demonstrate the validity of the proposed approach to establish the quality of on-wafer calibration approaches integrated in the back-end of line of Si-based technologies and to validate the compact model of CMOS devices up to (sub)mm-waves.
Increasing demand for cryogenic electronics aimed at quantum sensors and computing technologies asks for accurate and quantifiable calibration methods and techniques. In this work, we present a structured approach to generate the nominal RF responses of standard artifacts, enabling wideband vector network analyzer (VNA) calibration algorithms, i.e., short, open, load, and reciprocal (SOLR), at cryogenic temperatures. Moreover, we present an EM simulation strategy to generate the perturbations in the artifacts’ responses based on mechanical fabrication tolerances and calculate an equivalent RF response uncertainty. Both the nominal and perturbed standard responses are computed at (user defined) cryogenic temperatures, by combining thermo-mechanical responses with the electromagnetic solver. A circuit simulator-based measurement model (MM) is used to compute the uncertainties of the cryogenic setups used in this work. Error contributions arising from the propagation of VNA noise, switch nonidealities, calibration artifacts uncertainties, temperature fluctuations, and temperature gradient over the interconnects are included in the MM. For validation, measured results of a coaxial air transmission line at 77 K and 4.2 K are presented and compared with 3-D EM simulation predictions. Finally, the measurement uncertainties are detailed in a budget analysis describing the individual contributions.
Thanks to the large bandwidth availability, millimeter and sub-millimeter wave systems are getting more attractive to be used in a wide range of applications, such as high-resolution radar or high-speed communications. In this contribution, a new lens antenna in-package solution is presented for the H-band (220320 GHz), including a wideband quartz-cavity leaky-wave feed combined with an air-bridge chip interconnect technology, based on spray coating and laser lithography. This interconnection acts as a wideband, low-loss transition between the GaAs front-end and the quartz antenna, avoiding the use of expensive waveguide split-blocks. An antenna prototype including the interconnect has been manufactured and characterized, validating the full-wave simulated results for the integrated H-band leaky-wave with aperture efficiency higher than 74% over 34% bandwidth, and radiation efficiency higher than 70% over 37% of bandwidth.
We present a 132-147GHz power source based on four power amplifiers whose outputs are combined into a compact (0.52x0.48mm2 footprint) dielectric resonator antenna mounted on the chip face. The source, prototyped in 0.13μm SiGe BiCMOS, demonstrates an EIRP of 27dBm with a power-added efficiency of 13.8 %. Individual PAs deliver a peak Psat of 15dBm over a 3-dB bandwidth of 116-152GHz. Excited by shorted patches on chip, the maximum efficiency of the hybrid antenna is 80% over a 16% relative bandwidth. The EIRP and transmitted RF power are the highest reported for D-band silicon-based transmitters.
In this article, we present a comprehensive analysis of the hardware and software solutions required to enable frequency scalable load-pull test benches operating in the (sub)mm-wave frequency bands. First, the constraints arising from the harmonic (nonlinear) operation of mm-wave extender modules are discussed and analyzed. Then, different hardware solutions for signal generation and control, together with the specific software algorithms required to realize a frequency scalable load-pull test bench, are presented. The measurement setup key performances are analyzed in different frequency bands up to 500 GHz, i.e., waveguide bands from WR10 up to WR2.2. Finally, the load-pull measurements on an HBT device at 75 GHz and a two-stage differential PA at 135 GHz are presented to show the capability of the proposed test bench to characterize and optimize mm-wave nonlinear components.
A method is presented for automated probing of on-wafer devices for measurements at millimetre-wave frequencies. The proposed method automatically detects the contact between the measurement probe and on-wafer device, based on the evaluation of variation in the input reflection coefficient. It is shown that, using this automated technique, about five times better measurement repeatability is achieved in millimetre-wave device characterisation.
In this paper we present a method to alleviate the errors introduced by the bias dependency of the electrostatic discharge or antenna-effect protection diodes when a direct metal-one TRL calibration is employed. The proposed method shows that the two error-boxes produced by the TRL algorithm can be split and combined without introducing mathematical errors as long as the perturbation can be assumed to be a reciprocal network. A mathematical analysis is provided and initially bench marked against a circuit level simulation employing only s-parameter defined error boxes and ideal lumped components and after verified using 3D EM simulations of the test fixtures. The circuit level simulator confirms the mathematical analysis while the 3D EM simulator validates the applicability in a more realistic setting. Finally, the proposed method is used in a real measurement where the test fixture are implemented in a 28nm CMOS technology and characterized at frequencies between 140 GHz to 200 GHz. The measurement using the proposed method clearly shows reduced deviation from known reference when compared to the non-split approach.
In this paper we present the measurement procedure to achieve direct on-wafer absolute power calibration in VNA-based mm-wave setups. The proposed approach employs 28 nm CMOS n-channel MOSFET as the power calibration transfer device, providing sufficient responsivity up to 325 GHz. The square law conversion from mm-wave (power) to DC (voltage) through the CMOS device is employed to achieve a direct on-wafer power calibration. The use of the calibration transfer device allows for a (power) calibration procedure of a mm-wave measurement setup with zero extender movements, thus minimizing errors originating from cable movements, and reducing calibration time when compared to the standard, calorimeter based, procedure. The approach is experimentally benchmarked against the instrumentation power meters procedure in the WR5 band (140220 GHz), showing a maximum error propagated through the calibration equations, over the entire band and multiple devices, lower than 1 dB.