Micromachined Interfaces for Metrology and Packaging Applications in the Submillimeter-Wave Band

Author(s):  
Robert M. Weikle ◽  
H. Li ◽  
A. Arsenovic ◽  
S. Nadri ◽  
L. Xie ◽  
...  

The continued emergence of new terahertz devices has created a need for improved approaches to packaging, integration, and measurement tools for diagnostics and characterization in this portion of the spectrum. Rectangular waveguide has for many years been the primary transmission medium for terahertz and submillimeter-wave systems operating from 300 GHz to 1 THz, with the UG-387 flange the most common interface for mating waveguide components over this frequency range. Alignment of UG-387 flanges is accomplished with pins and alignment holes that are placed around the flange perimeter and, under the standard MIL SPECS tolerances, misalignments of up to 6 mils (150 microns) are possible as a result of practical milling tolerances. With the emergence of vector network analyzers operating beyond 1 THz, such misalignment of waveguide mating flanges is not negligible and is recognized as a fundamental issue limiting calibration and measurement precision at frequencies greater than 300 GHz. In response to this issue, a number of new waveguide flange concepts have been investigated to reduce flange misalignment and the P1785 IEEE Standard was recently issued to recommend designs for waveguide interfaces at frequencies above 110 GHz. Among the new flange concepts being proposed is a modified UG-387 that utilizes tighter machining tolerances and the ring-centered flange where alignment is accomplished using a precision coupling ring that fits over raised bosses that are centered on each waveguide. This paper discusses the new interface concepts that are being developed to address waveguide flange misalignment as well as emerging micromachined interconnects, calibration standards and heterogeneous integration methods that are being applied to implement low-loss and high-performance circuit architectures for the terahertz frequency range. Among the technologies that will be described are (1) design and characterization methods for the new ring-centered waveguide standard, (2) micromachined waveguide components and calibration standards for the terahertz band, (3) silicon-based micromachined probe structures for direct-contact interfacing and metrology, and (4) epitaxial transfer of III-V semiconductor material onto high-resistivity silicon to realize a low-loss platform for integration of terahertz components. Details of the processing methods used to realize these components as well as measurement techniques for assessing their performance will be described.

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hua-Lin Cai ◽  
Jing Zhan ◽  
Chen Yang ◽  
Xiao Chen ◽  
Yi Yang ◽  
...  

Several kinds of ferrite-integrated on-chip inductors are presented. Ferrite nanomaterial applied in RF on-chip inductors is prepared and analyzed to show the properties of high permeability, high ferromagnetic resonance frequency, high resistivity, and low loss, which has the potential that will improve the performance of RF on-chip inductors. Simulations of different coil and ferrite nanomaterial parameters, inductor structures, and surrounding structures are also conducted to achieve the trend of gains of inductance and quality factor of on-chip inductors. By integrating the prepared ferrite magnetic nanomaterial to the on-chip inductors with different structures, the measurement performances show an obvious improvement even in GHz frequency range. In addition, the studies of CMOS compatible process to integrate the nanomaterial promote the widespread application of magnetic nanomaterial in RF on-chip inductors.


2009 ◽  
Vol 68 (6) ◽  
pp. 549-554
Author(s):  
Yu. Ye. Kamenev ◽  
F. F. Sizov ◽  
V. N. Dobrovolsky

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1302
Author(s):  
Zhiyong Wu ◽  
Lei Zhang ◽  
Tingyin Ning ◽  
Hong Su ◽  
Irene Ling Li ◽  
...  

Surface plasmon polaritons (SPPs) have been attracting considerable attention owing to their unique capabilities of manipulating light. However, the intractable dispersion and high loss are two major obstacles for attaining high-performance plasmonic devices. Here, a graphene nanoribbon gap waveguide (GNRGW) is proposed for guiding dispersionless gap SPPs (GSPPs) with deep-subwavelength confinement and low loss. An analytical model is developed to analyze the GSPPs, in which a reflection phase shift is employed to successfully deal with the influence caused by the boundaries of the graphene nanoribbon (GNR). It is demonstrated that a pulse with a 4 μm bandwidth and a 10 nm mode width can propagate in the linear passive system without waveform distortion, which is very robust against the shape change of the GNR. The decrease in the pulse amplitude is only 10% for a propagation distance of 1 μm. Furthermore, an array consisting of several GNRGWs is employed as a multichannel optical switch. When the separation is larger than 40 nm, each channel can be controlled independently by tuning the chemical potential of the corresponding GNR. The proposed GNRGW may raise great interest in studying dispersionless and low-loss nanophotonic devices, with potential applications in the distortionless transmission of nanoscale signals, electro-optic nanocircuits, and high-density on-chip communications.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 169
Author(s):  
Mengcheng Wang ◽  
Shenglin Ma ◽  
Yufeng Jin ◽  
Wei Wang ◽  
Jing Chen ◽  
...  

Through Silicon Via (TSV) technology is capable meeting effective, compact, high density, high integration, and high-performance requirements. In high-frequency applications, with the rapid development of 5G and millimeter-wave radar, the TSV interposer will become a competitive choice for radio frequency system-in-package (RF SIP) substrates. This paper presents a redundant TSV interconnect design for high resistivity Si interposers for millimeter-wave applications. To verify its feasibility, a set of test structures capable of working at millimeter waves are designed, which are composed of three pieces of CPW (coplanar waveguide) lines connected by single TSV, dual redundant TSV, and quad redundant TSV interconnects. First, HFSS software is used for modeling and simulation, then, a modified equivalent circuit model is established to analysis the effect of the redundant TSVs on the high-frequency transmission performance to solidify the HFSS based simulation. At the same time, a failure simulation was carried out and results prove that redundant TSV can still work normally at 44 GHz frequency when failure occurs. Using the developed TSV process, the sample is then fabricated and tested. Using L-2L de-embedding method to extract S-parameters of the TSV interconnection. The insertion loss of dual and quad redundant TSVs are 0.19 dB and 0.46 dB at 40 GHz, respectively.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3230
Author(s):  
Theeranuch Nachaithong ◽  
Narong Chanlek ◽  
Pairot Moontragoon ◽  
Prasit Thongbai

(Co, Nb) co-doped rutile TiO2 (CoNTO) nanoparticles with low dopant concentrations were prepared using a wet chemistry method. A pure rutile TiO2 phase with a dense microstructure and homogeneous dispersion of the dopants was obtained. By co-doping rutile TiO2 with 0.5 at.% (Co, Nb), a very high dielectric permittivity of ε′ » 36,105 and a low loss tangent of tanδ » 0.04 were achieved. The sample–electrode contact and resistive outer-surface layer (surface barrier layer capacitor) have a significant impact on the dielectric response in the CoNTO ceramics. The density functional theory calculation shows that the 2Co atoms are located near the oxygen vacancy, creating a triangle-shaped 2CoVoTi complex defect. On the other hand, the substitution of TiO2 with Nb atoms can form a diamond-shaped 2Nb2Ti complex defect. These two types of complex defects are far away from each other. Therefore, the electron-pinned defect dipoles cannot be considered the primary origins of the dielectric response in the CoNTO ceramics. Impedance spectroscopy shows that the CoNTO ceramics are electrically heterogeneous, comprised of insulating and semiconducting regions. Thus, the dielectric properties of the CoNTO ceramics are attributed to the interfacial polarization at the internal insulating layers with very high resistivity, giving rise to a low loss tangent.


Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos

Additive Manufacturing (AM) encompasses a broad variety of fabrication techniques characterized by successive additions of mass and/or energy to a build domain. AM processes have been developed for a wide variety of feedstock materials, including metals, polymers, and ceramics. In the present work we study the AM of ceramics using the Direct Ink Writing (DIW) technique. We performed comparative studies between additively manufactured and conventionally manufactured test articles, in order to quantify the variations in output geometry and mechanical properties induced by the DIW process. Uniaxial tests are conducted using high-performance optical strain measurement techniques. In particular, it is shown that the DIW-produced specimens exhibit anisotropic shrinkage when fired, as well as a marked decrease in stiffness and ultimate strength. We conclude with a discussion of potential mechanisms which may be responsible for these property degradations, and introduce potential adaptations to the DIW AM process that may be effective in combating them.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammad Rakibul Islam ◽  
Md. Arif Hossain ◽  
Syed Iftekhar Ali ◽  
Jakeya Sultana ◽  
Md. Saiful Islam

AbstractA novel photonic crystal fiber (PCF) based on TOPAS, consisting only rectangular slots is presented and analyzed in this paper. The PCF promises not only an extremely low effective material loss (EML) but also a flattened dispersion over a broad frequency range. The modal characteristics of the proposed fiber have been thoroughly investigated using finite element method. The fiber confirms a low EML of 0.009 to 0.01 cm−1 in the frequency range of 0.77–1.05 THz and a flattened dispersion of 0.22±0.01 ps/THz/cm. Besides, some other significant characteristics like birefringence, single mode operation and confinement loss have also been inspected. The simplicity of the fiber makes it easily realizable using the existing fabrication technologies. Thus it is anticipated that the new fiber has the potential to ensure polarization preserving transmission of terahertz signals and to serve as an efficient medium in the terahertz frequency range.


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