Below is a list of the posters (listed alphabetically) presented by our students at the Engineering Graduate Research Symposium. Great work to everyone who participated!
Poster Number: ECE-11
Authors: Jennifer Byford; Saranraj Karuppuswami; Premjeet Chahal
Title: Broad-band Dielectric Probes for THz Device Characterization
Abstract: There is great interest in terahertz technology and research. As terahertz technology grows in use, especially with a growing number of on-wafer devices moving towards operation in this frequency range, there is a need to easily measure and characterize these on-wafer circuits and systems. Most commercially available THz systems are quasi-optical and thus require some kind of probe to couple the THz waves produced by these systems with the devices under test (DUTs). Although various THz probe designs have been proposed in the literature, many use metal wires which have practical limitations, and other dielectric based probes are designed for commercially available W-Band systems as opposed to THz systems. There are additional parameters to consider for on-wafer applications specifically such as efficient coupling and limiting cross-talk between the probes and nearby devices which are not the DUT. Here, we investigate the design, fabrication, and evaluation of dielectric based probes for coupling THz waves produced from quasi-optical systems into on-wafer applications. Different designs are explored through simulation and the most optimized designs are fabricated and tested. The probes coupling effectiveness and cross-talk susceptibility is also evaluated. In this work, an Emcore PB7200 frequency domain terahertz (0.1 - 2 THz) system is used to evaluation probe performance. The design of the components and different manufacturing process are presented. Simulations were carried out in ANSYS Electronics Desktop using HFSS. On-wafer probing applications are demonstrated with the components and future work is discussed.
Poster Number: ECE-15
Authors: Michael Craton; Mohd Ifwat Mohd Ghazali; Brian Wright; Kyoung Youl Park; Premjeet Chahal; John Papapolymerou
Title: 3D Printed Microfluidic Cooling for High Power RF Applications
Abstract: This paper presents the design and fabrication of microfluidic channel integration in a plastic substrate using 3D printing. The microfluidic channels are integrated along with a copper plate which the coolant is in direct contact with. To demonstrate the design, a diode intended for switched power supplies is integrated onto the copper plate and its performance characterized. 3D printing or additive manufacturing (AM) allows for fast prototyping of such package designs and can be readily adopted in the fabrication of RF circuits. This paper, to the best of our knowledge, for the first time will demonstrate a 3D printed integrated microfluidic channel for the cooling of electronic circuits. Details of design, fabrication and characterization are presented.
This work was supported in part by MSU Foundation Professorship
Poster Number: ECE-17
Authors: Vincens Gjokaj; Premjeet Chahal
Title: 3D Printed Hybrid Coaxial-Like Transmission Line
Abstract: In this paper a new hybrid technology is introduced which combines flexible Liquid Crystal Polymer (LCP) films with 3D printed metal coated plastic rigid shells to design novel low-loss microwave and millimeter wave components. The process is low-cost and simplifies the manufacturing of these high-end products. Here, a simple coax-like transmission line and a novel low-loss bandpass filter are demonstrated. This work establishes a new way of utilizing 3D printing to create ultra low-loss structures and opens a pathway to manufacture these complex structures with ease using a table top system. In addition, novel structures can be manufactured which would have been difficult, if not impossible, using conventional machining techniques.
Poster Number: ECE-19
Authors: Yuxiao He; John Papapolymerou; Collaborators from Gergia Tech: Eric Drew; Wei-ya Chen; Z.J. Zhang
Title: Fabrication and Characterization of Thick (>100 um) CoFe2O4 and MnFe2O4 Nanoparticle Films with the Aid of 3D Printing Technology
Abstract: This work presents the fundamental studies on ferromagnetic resonance (FMR) of nanoparticles, the fabrication and the characterization of the magnetic nanoparticle films on the 3D printed testbed. First we explore the FMR profiles of various magnetic nanoparticles and their corresponding magnetic susceptibilities. Then two novel methods, which are the Layer-By-Layer process and the Solution Cast method, are proposed and proven to be effective to fabricate the magnetic films with various thicknesses using CoFe2O4 and MnFe2O4 nanoparticles. Especially the 450 um thick MnFe2O4 film is to the best of the author's knowledge, the thickest magnetic film that has ever been reported. Next the 3D printed transmission line and fixture are utilized to characterize the magnetic films. By matching the simulated and measured group delay, the relative permeability of the CoFe2O4 film is estimated as 40. The FMR effects are observed when the DC magnetic field bias is applied to the stripline under all five power levels. In particular, the FMR effects appear successively within three frequency bands, namely 4 – 8 GHz, 8 - 14 GHz and 12 - 18 GHz, as the magnetic field strength increases. Moreover, the attenuation also increases under stronger bias and maintains decent performance even at low RF input power. This work presents for the first time a new stripline that is cost effective, easy to assemble and has good frequency selectivity, which paved the way for fabricating RF circuits and components using the magnetic nanoparticles in a wide range of power-sensitive and broadband microwave applications.
This work was supported in part by National Science Foundation (NSF)
Poster Number: ECE-23
Authors: Saranraj Karuppuswami; Jennifer Byford; Premjeet Chahal
Title: Volatile Molecular Sensors Using Terahertz Resonators on Porous Substrates
Abstract: Volatiles emitted from fuels and automobile exhaust, paints, varnishes and sprays, industrial exhaust, etc. pose significant health risk and their detection in the environment is necessary to provide timely warning to public in a local environment. Among the many techniques that can be utilized such as optical, microwave, gas chromatography, colorimetric analysis and mass spectrometry, sensing of volatiles with terahertz (THz) radiation is attractive as it provides an approach to achieve high sensitivity coupled with specificity. Many volatile molecules exhibit unique spectral signatures in the THz spectral range and higher absorption strength than the microwave regime leading to strong interaction with the THz wave. Yet, THz volatile sensing technology has not grown to its full potential due to the need for a controlled low pressure gas environment to be able to measure narrow band absorption or spectral peaks. The lower sensitivity of THz volatile sensors at atmospheric pressure is due to the increased rate of molecular collisions leading to broadening of the spectral peaks, making it impossible to distinguish between different spectral signatures. To overcome this challenge, a
practical approach for volatile molecular sensing at atmospheric pressure and room temperature in the THz regime is investigated in this paper by utilizing porous substrates which naturally allows condensing of gas molecules in pores through capillary condensation. Capillary condensation is dictated by pore sizes, density of pores and surface tension. All of these properties are investigated here to achieve high sensitivity. In order to further enhance sensitivity, different types of THz resonators are designed on the porous substrate and are characterized for different molecule sensing (having different boiling point and dielectric properties). Resonators allows easier interrogation of frequency shift due to dielectric loading of porous substrates. For the measurement, the substrate containing THz resonators are placed in the optical beam path of the THz signal and measured as a function of frequency using an Emcore PB7200 frequency domain terahertz measurement system. In order to control the exposure environment, the sensing elements are placed in an enclosed chamber and known volumes of volatile molecules with air mixture are introduced. Both adsorption and desorption rates on the porous surface as a function of time is investigated for specificity of different volatile molecules.
This work was supported in part by The Axia Institute
Poster Number: ECE-24
Authors: Deepak Kumar; Saikat Mondal; Saranraj Karuppuswami; Yiming Deng; Premjeet Chahal
Title: A Wireless PZT Based Harmonic Tag for Remote Vibration Detection
Abstract: Fault detection and monitoring techniques are necessary for continuous and smooth operation of machines in almost every industrial field. In recent years, the focus of the research has turned towards development of low cost and reliable technology for condition-monitoring and predictive maintenance of machines. Vibration analysis plays a vital role in analyzing the structural integrity of machines and provides insights for predictive maintenance. Monitoring of vibration pattern in machines allows detection of anomaly in a timely manner reducing the economic loss associated with a breakdown. There are many techniques developed in literature ranging from acoustics such as piezoelectric and PVDF to vibrometry. Most of the techniques have common limitations such as limited read range, prone to clutter and lower signal to noise ratio. In order to improve sensitivity and overcome these limitations, a piezoelectric based harmonic tag is investigated for vibration detection
The sensor tag consists of a PZT material coupled to a harmonic passive wireless tag. Under vibration, the PZT material generates a time varying voltage, which affect the reflected signal. The RF tag modulates the interrogation RF signal according to the bias voltage and produces a time varying harmonic signal. The design, fabrication and measurement of the proposed sensor tag is presented.
This work was supported in part by DOT
Poster Number: ECE-25
Authors: Mohd Ifwat Mohd Ghazali; Kyoung Youl Park; Premjeet Chahal
Title: 3D Printed Metalized Plastic Waveguides for Microwave Components
Abstract: This paper investigates the design and fabrication of 3D printed waveguide and their application for the design of microwave passive components. This includes a simple waveguide structure, a band pass filter, waveguide power splitter, a leaky wave antenna and a slot antenna array. A Lego-like approach is used to assemble different 3D printed sub-sections after metal coating. Details of modeling, fabrication and measurement are presented, and simulation and measured results match closely.
Poster Number: ECE-26
Authors: Saikat Mondal; Mohd Ifwat Mohd Ghazali; Saranraj Karuppuswami; Amanpreet Kaur; Premjeet Chahal
Title: A Nonlinear Transmission Line based Harmonic RF Tag
Abstract: This paper describes the design and development of a nonlinear transmission line (NLTL) based passive RFID tag. When the tag receives a signal from the interrogator, it generates harmonics which are transmitted back to interrogator. The reflected signal is distorted in time domain due to the harmonic contents. Hence, a change in the rise time would be observed in the received signal.
This work was supported in part by Department of Transportation
Poster Number: CMSE-03
Authors: Zane Crawford; Shanker Balasubramaniam
Title: Bayesian Analysis of Differential Equations
Abstract: Many numerical solvers exist to solve differential equations for some domain given a number of initial conditions. In the problems of interest, the differential equations are assumed to be deterministic, and can be solved with methods such as Euler, Runge-Kutta, and Adams-Basforth to perform an integral based on some quadrature rule. These methods use successive approximations of the dependent variable to find a valid solution to the differential equation, with the approximations contributing to the error. However, because the true value of the solution to the differential equation is not known, a probabilistic framework can be formed. In this work, we review Bayesian analysis to solve differential equations, in which the differential equation is treated as a Bayesian inference problem. An algorithmic approach to solving partial differential equations will be presented and compared to other explicit and implicit numerical methods. Results solving problems in one dimension will be presented.
This work was supported in part by Department of Energy Computational Science Graduate Fellowship