2X-Thru, 1X-Reflection, and Thru-Line de-embedding: Theory, sensitivity analysis, and error corrections

Due to the simplicity of design and measurement, as well as the accuracy of results, the 2X-Thru de-embedding (2XTD), 1X-Reflection de-embedding (1XRD), and Thru-Line de-embedding (TLD) have been replaced the traditional de-embedding algorithms, such as TRL and SOLT. In this dissertation, theory of 2n-port 2XTD, 1XRD, and TLD are completely derived first. The self-error reduction schemes is introduced to mitigate the de-embedding errors due to non-ideal manufacturing effects of non-zero mode conversion terms, as well as the asymmetric, and manufacturing variations. The validations are performed on both theory and self-error reduction through simulation and measurements cases. The 2X-Thru de-embedding (2XTD) is discussed in details. The prevailing 2X-Thru de-embedding (2XTD) requires much less calibration standards, yet still maintain the high accuracy of de-embedded results. Nevertheless every de-embedding method is based on the rigorous mathematical derivations, the manufacturing variations are inevitable. IEEE P370 committee provided the manufactured test coupons with golden standard to test the accuracy of different de-embedding methods when considering the manufacturing variations. Such manufacturing variations are propagated to the de-embedded results through the sensitivity of the test fixtures. The error reductions scheme in this section mitigates the de-embedded errors by correcting some of the manufacturing variations in the algorithm. This section will focus on the three kinds of manufacturing variations: 1) test fixture asymmetry; 2) the perturbations of the test fixtures in the calibration structure of 2X-Thru and de-embedding structure of Total; 3) the mode conversion terms due to the manufacturing variations --Abstract, page iv

Undesired-Resonance Analysis and Modeling of Differential Signals Due to Narrow Ground Lines Without Stitching Vias

Undesired Resonances on High-Speed Differential Signals Are Studied in This Paper, which is Caused by the Adjacent Narrow Ground Line Without Stitching Vias. Due to Space Limitations in the High-Speed Channel Layouts of Certain Package Applications, the Ground (GND) Line is Often Narrow and Has Insufficient Stitching Vias, Potentially Causing Undesired Resonance in High-Speed Differential Signals. in This Study, These Undesired Resonances Were Investigated using 3D Simulations, revealing that They Can Be Modeled as Parallel-Coupled Half-Wavelength Resonance. the Resonance Frequency of the Parallel-Coupled Half-Wavelength Resonance Structure Can Be Predicted Well using the Formula based on the GND Line Length. Moreover, Three Potential Solutions to Undesired Resonance Are Proposed, Providing a Practical Guide for GND Line Routing in Specific Applications

Anion Dependent Self-Assembly of Polynuclear Cd-Ln Schiff Base Nanoclusters: NIR Luminescent Sensing of Nitro Explosives

Two types of polynuclear Cd-Ln complexes [CdLnL(NO3)Cl2(DMF)2] [Ln = La (1) and Nd (2)] and [Ln2CdL2(NO3)2(DMF)2](OH)2 [Ln = La (3) and Nd (4)] were constructed using a new Schiff base ligand which has a long backbone with two phenyl groups. The Schiff base ligands show a “twist” configuration in 1–4. The crystal structures show that the molecular dimensions of 3 and 4 are about 6 × 10 × 15 Å. The Cd-Nd complexes 2 and 4 exhibit the typical NIR luminescence of Nd3+. Interestingly, 4 shows the luminescent sensing of nitro explosives and exhibits a high sensitivity to 2-nitrophenol at the ppm level

2x-Thru De-Embedding for Non-2ᶰ Even Number Port Network

2N-port de-embedding has been well studied previously by using the higher order modal-based S-parameters. Such idea is successfully validated by using the 2x-Thru de-embedding, as well as the classic TRL. Non-2N even number (such as 6, 10, 12, etc.) port network S-parameters de-embedding is derived and validated in this paper. By inserting a factitious single-ended 2x-Thru before the fixture characterization, the derivation and validation are demonstrated through a 6-port 2x-Thru de-embedding example. After the fixture characterization, the inserted artificially single-ended 2x-Thru will be removed before the step of fixture removing calculation. As the 2x-Thru de-embedding application always has even number of port 2x-Thru fixtures, the idea in this paper extend the 2x-Thru de-embedding to any arbitrary number of port. The derivation and justification are also suitable for other de-embedding algorithms with even number of port

A Novel De-Embedding Method Suitable for Transmission-Line Measurement

A novel de-embedding method on transmission line device under testing (DUT) is introduced in this paper. The technique can be used as an alternative to classic calibration approaches, such as SOLT, TRL, LRM, or LRRM whenever the de-embedded structure is a transmission line. The method only requires two measurement patterns: a true through as test fixture and a total pattern with targeting DUT embedded in. With a quasi-symmetry requirement in test fixtures, it is also a good substitute for newly released two-pattern de-embedding methodologies which have rigid symmetric demanding in text fixtures design and manufactures

Advanced On-Chip SOL Calibration Method for Unknown Fixture De-embedding

SOL (Short, Open and Load) calibration based on iterative error sensitivity is proposed in this paper. With advanced SOL calibration, unknown parasitic parameters at on-chip terminations are accurately estimated up to 20 GHz. Artificial terminations are designed on printed circuit board (PCB) to experiment the proposed method. On-chip SHORT, OPEN and LOAD fabricated inside silicon shows the accuracy of proposed calibration method through the comparison with known fixture S-parameter after de-embedding

Fast Transmitter and Receiver Eye Diagrams Acquisition in the MIPI D-PHY Interface

The mobile industry processor interface (MIPI) standards defines industry specification for design of mobile devices such as smartphone, tables, laptop and hybrid devices. Such standard plays a critical role in the Internet of Things (IoT), 5G mobile devices, as well as autopilot automobiles. MIPI specification has comprehensive requirements on the data storage, data transfer, display, camera, memory, power, etc on the transmitter and receiver. In the testing phase, the transmitter and receiver may not be easily directly measured. Herein, a fast transmitter and receiver eye diagrams calculation methodology is necessary to predict the RX and TX performances of those devices. The calculated RX and TX eye diagrams are evaluated by using the D-PHY protocol to identify the quality of the signals. An in-house MIPI tool is built to directly display the calculated eye diagrams as well as the MIPI D-PHY report in the PC. The validations are performed by using both simulation and measurement examples

Accurate Characterization of PCB Transmission Lines for High Speed Interconnect

Accurate PCB transmission-line characterization can be challenging due to the effect of test fixtures and launching vias, etc. In this paper, VNA measurements with innovative de-embedding approaches, including those that utilize only one \u272X-Thru\u27 calibration standard are studied. The 2X-Thru de-embedding method is first shown to be correlated to existing TRL calibration method. Test boards built with varying lengths of transmission lines routed on different layers were then characterized with the new de-embedding method. Excellent de-embedded results are achieved for frequencies up to 30 GHz

De-Embedding Comparisons of 1X-Reflect SFD, 1-Port AFR, and 2X-Thru SFD

The procedures of lX-Reflect Smart Fixture De-embedding (SFD), 1-Port Auto Fixture Removal (AFR), and 2X-Thru SFD are compared from various perspectives: test fixture design, the de-embedding procedure, and the de-embedded results. The accuracy of the fixture characterization and de-embedded result is the key figure of merit (FOM) in each de-embedding method. Full-wave models were built to evaluate the FOM of these three methods, by comparing the scattering parameters (S-parameters) and TDR. A test coupon for measuring the USB-C cables is adopted to serve as manufactured validation purpose