A Novel Approach to the Measurement and Characterization of Losses due to Surface Roughness in High Speed Transmission Lines

2011 ◽  
Vol 2011 (CICMT) ◽  
pp. 000241-000245
Author(s):  
Femi Akinwale ◽  
A. Ege Engin

An accurate measurement technique is required to fully characterize the losses observed at high frequencies in transmission lines. Evaluation of losses seen at high frequencies is necessary to meet the high-speed data transfer rates that future applications will demand. Conductor properties and losses are two critical issues in signal path characterization. The nature of conductor losses is not well understood at high speeds. Classical models used for predicting the effects of surface roughness on signal propagation are known to breakdown around 5 GHz. Novel methods are sought to quantify the effects beyond 5 GHz. In this paper, a simple methodology to extract conductor loss is derived and validated based on a stripline configuration of two different widths. The proposed methodology is applicable to surface roughness loss characterization of both organic and ceramic packaging materials.

2022 ◽  
Vol 43 (1) ◽  
pp. 012302
Author(s):  
K. S. Zhuravlev ◽  
A. L. Chizh ◽  
K. B. Mikitchuk ◽  
A. M. Gilinsky ◽  
I. B. Chistokhin ◽  
...  

Abstract The design, manufacturing and DC and microwave characterization of high-power Schottky barrier InAlAs/InGaAs back-illuminated mesa structure photodiodes are presented. The photodiodes with 10 and 15 μm mesa diameters operate at ≥40 and 28 GHz, respectively, have the output RF power as high as 58 mW at a frequency of 20 GHz, the DC responsivity of up to 1.08 A/W depending on the absorbing layer thickness, and a photodiode dark current as low as 0.04 nA. We show that these photodiodes provide an advantage in the amplitude-to-phase conversion factor which makes them suitable for use in high-speed analog transmission lines with stringent requirements for phase noise.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000379-000385 ◽  
Author(s):  
Brett Sawyer ◽  
Yuya Suzuki ◽  
Zihan Wu ◽  
Hao Lu ◽  
Venky Sundaram ◽  
...  

This paper describes the design, fabrication, and characterization of a two-metal layer RDL structure at 40 um pitch on thin glass interposers. Such an RDL structure is targeted at 2.5D glass interposer packages to achieve up to 1 TB/s die-to-die bandwidth and off-interposer data rates greater than 400 Gb/s, driven by consumer demand of online services for mobile devices. Advanced packaging architectures including 2.5D and 3D interposers require fine line lithography beyond the capabilities of current organic package substrates. Although silicon interposers fabricated using back-end-of-line processes can achieve these RDL wiring densities, they suffer from high electrical loss and high cost. Organic interposers with high wiring densities have also been demonstrated recently using a single sided thin film process. This paper goes beyond silicon and organic interposers in demonstrating fine pitch RDL on glass interposers fabricated by low cost, double sided, and panel-scalable processes. The high modulus and smooth surface of glass helps to achieve lithographic pitch close to that of silicon. Furthermore, the low loss tangent of glass helps in reducing dielectric losses, thus improving high-speed signal propagation. A semi-additive process flow and projection excimer laser ablation was used to fabricate two-metal layer RDL structures and bare glass RDL layers. A minimum of 3 um lithography and 20 um mico-via pitch was achieved. High-frequency characterization of these RDL structures demonstrated single-ended insertion losses of −0.097 dB/mm at f = 1 GHz and differential insertion losses of −0.05 dB/mm at f = 14 GHz.


2017 ◽  
Vol 4 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Sami Barmada ◽  
Marco Dionigi ◽  
Paolo Mezzanotte ◽  
Mauro Tucci

In this contribution, the authors perform the design and show the experimental results relative to a prototype of a combined wireless power transfer (WPT)–power line communications (PLC) system, in which the WPT channel is interfaced to a PLC environment to allow data transfer when the cabled connection is no longer available. The main rationale behind this idea stays in the fact that PLC communication is now a popular choice to enable communications, for instance, in smart grids and in home automation, while WPT devices start to be available in the market (i.e. for mobile phones) and soon they will be a reality also for higher power (i.e. vehicle battery charging). In particular, theoretical insights about the requirements of the system are given; a two coils system has been implemented and a measurement campaign, together with simulations, show that the system is of great potentiality and could be used in applications where both wireless power and data transfer are needed (such as vehicles battery charging), achieving maximum power transfer and good data rate in order to transmit high-speed signals.


2018 ◽  
Vol 2018 (1) ◽  
pp. 000380-000383
Author(s):  
A. Ege Engin ◽  
Ivan Ndip ◽  
Klaus-Dieter Lang ◽  
Jerry Aguirre

Abstract High-speed transmission lines are commonly routed as differential lines to control sensitivity to noise on the reference planes at higher speeds. The preferred method of characterization of differential lines is in terms of mixed-mode scattering parameters, as they provide insight into the behavior of differential and common signals, as well as the mode conversion among them. These mixed-mode scattering parameters can be mathematically obtained from single-ended parameters, which can for example be measured with a 4-port vector network analyzer. There has been recent concerns about the so-obtained mixed-mode scattering parameters, especially for tightly-coupled lines, resulting in extended or modified definitions of mixed-mode scattering parameters. This can be a point of confusion in interpreting the behavior of differential lines. In this paper we introduce the mixed-port hybrid parameters, which do not suffer from any such ambiguous definitions, as they are based on intuitive differential and common-port excitations of the network. As such, mixed-port hybrid parameters can be used to analyze the mixed-mode performance of any arbitrary 4-port network, certainly including coupled or asymmetrical lines, without any ambiguity.


2016 ◽  
Vol 13 (3) ◽  
pp. 128-135
Author(s):  
Brett Sawyer ◽  
Yuya Suzuki ◽  
Zihan Wu ◽  
Hao Lu ◽  
Venky Sundaram ◽  
...  

This article analyzes redistribution layer (RDL) technologies needed for 2.5-dimensional (2.5-D) die integration on thin glass interposers and developed using low-cost processes. The design, fabrication, and characterization of a four-metal layer RDL buildup required for wide input/output (I/O) routing at 40-μm bump pitch and a two-metal layer RDL buildup fabricated directly on glass for high-speed, off-package signaling are described. Such RDL technologies are targeted at 2.5-D glass interposer packages to achieve up to 1 Tb/s die-to-die bandwidth and off-interposer data rates > 400 Gb/s, driven by consumer demand of online services for mobile devices. Advanced packaging architectures including 2.5-D and 3-D interposers require fine-line lithography beyond the capabilities of current organic package substrates. High electrical loss and high cost are characteristic of silicon interposers fabricated using back-end-of-line (BEOL) processes that can achieve RDL wiring densities required for 2.5-D die integration. Organic interposers with high wiring densities have also been demonstrated using a single-sided, thin-film process. This article goes beyond silicon and organic interposers in demonstrating fine-pitch RDL on glass interposers fabricated by low-cost, double-side, and panel-scalable processes. The high modulus and smooth surface of glass help to achieve lithographic pitch close to that of silicon. Furthermore, the low permittivity and low loss tangent of glass reduce dielectric losses, thus improving high-speed signal propagation. A semiadditive process flow and projection excimer laser ablation were used to fabricate four-metal layer (2 + 0 + 2) fine-pitch RDL and two-metal layer RDL directly on glass. A minimum of 3 μm lithography and 20 μm microvia pitch was achieved. High-frequency characterization of these RDL structures demonstrated single-ended insertion losses of −0.097 dB/mm at f = 1 GHz and differential insertion losses of −0.05 dB/mm at f = 14 GHz.


Author(s):  
Valentina Korchnoy ◽  
Jacov Brener

Abstract High frequency signal propagation through transmission lines has been an important discipline for RF engineers. With advancements in digital technologies, especially when data rates reached multiple Gb/s, package designers have to consider parameters such as transmission loss and trace impedance in order to maintain signal integrity. For high frequency signals, the surface roughness of the copper trace becomes increasingly significant in determining conduction loss, due to current confinement to the conductor surface by the skin effect. Accurate 3D conductor surface maps are required for correct trace insertion loss simulation. Practical methods for package trace exposure and 3D surface height map acquisition are discussed in this paper. Advantages and disadvantages of these methods, and their implementation to real packages are shown. Using electrical parameters resulting from a 3D trace surface map, the error between electrical simulations and actual measurements of insertion loss in an FCBGA package have been reduced from 6% to nearly zero, enabling tighter margins in 10GB/s high speed serial design.


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