There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Introduction to Electromagnetic Compatibility

Antenna Theory And Design

Before the emergence of ultra-wideband (UWB) radios, widely used wireless communications were based on sinusoidal carriers, and impulse technologies were employed only in specific applications (e.g. radar). In 2002, the Federal Communication Commission (FCC) allowed unlicensed operation between 3.1–10.6 GHz for UWB communication, using a wideband signal format with a low EIRP level (−41.3dBm/MHz). UWB communication systems then emerged as an alternative to narrowband systems and significant effort in this area has been invested at the regulatory, commercial, and research levels.

IEEE Transactions on Microwave Theory and Techniques and Antennas and Propagation Announce a Joint Special Issue on Ultra-Wideband (UWB) Technology

Plated through-hole (PTH) vias are commonly used in printed circuit boards. They usually leave open stubs if the signal(s) does not transition the entire depth of the board. These open stubs can have a negative impact on signal transmission. This summary reports the investigation of the impact of the open via stubs in a typical backpanel design.

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Effects of open stubs associated with plated through-hole vias in backpanel designs

Near-field coupling in mixed digital/RF circuit design is critical to system sensitivity for modern high speed electronic systems. This paper presents radiation noise source modeling methods and applies equivalent noise source models to near-field coupling estimations. The noise source can be either modeled by physics-based dipole moment model or Huygens's equivalent model with data obtained from near-field scanning. The fundamental principles of both methods are first studied by simulation. A clock buffer integrated circuit is first modeled as a dipole moment model. The tangential fields on Huygens's box can be calculated by a dipole moment model with negligible multiple scattering effect assumption. The noise coupling then can be obtained by surface integration of Poynting vector at the RF antenna receiving port by full-wave simulation.

Radiation Noise Source Modeling and Application in Near-Field Coupling Estimation

In this paper, an error bound analysis is performed for 2x thru de-embedding methods: AFR (Automatic Fixture Removal) and SFD (Smart Fixture De-embedding). Basically, a certain amount of error is assumed to exist in S11 of 1x. This error will cause the de-embedded results to vary within a certain range. The upper bound and lower bound of the magnitude of the de-embedded results are given.

Error bounds analysis of de-embedded results in 2x thru de-embedding methods

Signal integrity (SI) and power integrity (PI) modelling and design require accurate knowledge of dielectric properties of printed circuit board (PCB) laminate dielectrics. Dielectric properties of a laminate dielectric can be obtained from a set of the measured S-parameters on a PCB stripline with a specially designed through-reflect-line (TRL) calibration pattern. In this work, it is proposed to extract dielectric properties from the measurements of S-parameters on the two 50-Ohm stripline structures of the same length, but different widths of the trace, designed on the same layer of a PCB. The dielectric properties on these two lines should be identical. However, an application of the simplest "root-omega" technique to extract dielectric properties of the substrate would lead to the ambiguity in the extracted data. This is because the conductor surface roughness affects the measured S-parameters and is lumped in the extracted dielectric data. This problem of ambiguity in the dielectric properties extraction can be overcome using the approach analogous to the recently proposed method to separate dielectric and conductor losses on PCB lines with different widths and roughness profiles (1).

Characterization of PCB Dielectric Properties Using Two Striplines on the Same Board

A test mechanism includes test equipment to measure frequency-domain data, such as scattering or S parameters. The S parameters are transformed to a different type of network parameters, such as transmission or T parameters. Contributions of test fixtures can be easily removed for the overall T-parameter matrix of a device under test connected in cascade with the test fixture. The test mechanism provides accurate measurement of a device under test represented by a multi-port (greater than two ports) network that is cascaded with another multi-port network representing the test fixture.

Jun Fan

Papers

Effects of open stubs associated with plated through-hole vias in backpanel designs

Radiation Noise Source Modeling and Application in Near-Field Coupling Estimation

Error bounds analysis of de-embedded results in 2x thru de-embedding methods

Characterization of PCB Dielectric Properties Using Two Striplines on the Same Board

Characterizing multi-port cascaded networks