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Fringe Capacitance of Open-Ended Coax

Termination Type

  • Flush Radiating Open: The termination is a flush cross-section of a bare coax cable, surrounding objects and radiation loss makes it somewhat unpredictable in practical uses.

  • Flush Flange Radiation Open with Flange: The outer conductor is extended perpedicular to the axial direction of the coax, creating a ground plane. This geometry is commonly

2D and 3D Field Solver Analysis of Differential Microstrips on JLCPCB's FPC Substrate

The following FPC configurations have been analyzed using TNT-MMTL, a free and open-source 2D field solver using electrostatic approximation and MoM.

TNT-MMTL is efficient but cannot simulate "true" floating conductors (such as an unconnected shield), the conductor must be either a signal conductor (albeit unexcited) or an ideal grounded conductor. Hence, openEMS is used to perform 3D full-wave simulations to cross-verify the shielded results.

SMA Connector Pin & Dielectric Tolerances

You're in a maze of incompatible SMA connectors, all alike.

SMA connectors are the most common microwave connector, widely used in analog and digital signal transmission and measurement. However, it suffers from inconsistent standard, a problem rarely known outside metrology labs. Most connectors on the market are not designed for lab applications, this problem affects most commercial, industrial and even military grade connectors. Their center pin and dielectric positions often have loose tolerances, potentially

JLCPCB

JLC04161H-7628 (1.59 mm ± 10% nominal)

Layer Material Thickness (mm) Note
L1 Copper 0.035 1 oz
Prepreg 7628 (49% RC) 0.21040
L2 Copper 0.0152
@biergaizi
biergaizi / openems_eng_ext_deps.md
Last active June 18, 2023 19:09
Dependency Issues of openEMS Engine Extensions

To implement loop tiling, the 3D space must be broken into independent tiles according to the data dependencies of the FDTD kernel. Thus, each tile must be "self-contained" without the need to access field coordinates outside the cell - There should be no "spooky action from a distance".

However, some openEMS engine extensions break this assumption:

Engine Compatible
engine_ext_cylinder.cpp No?
@biergaizi
biergaizi / openems.md
Created January 12, 2023 03:20
Running openEMS and pyEMS Simulations

The following insturctions have been tested on Fedora 36.

Install openEMS

  1. Clone the git repository

     cd ~/
     git clone --recurse-submodule https://github.com/thliebig/openEMS-Project.git
    
  2. Install Dependencies

@biergaizi
biergaizi / keybase.md
Created February 13, 2015 07:21
keybase.md

Keybase proof

I hereby claim:

  • I am biergaizi on github.
  • I am biergaizi (https://keybase.io/biergaizi) on keybase.
  • I have a public key whose fingerprint is 2552 11B2 395A 5A3E 0E48 A0F1 FAD3 EB05 E88E 8D6D

To claim this, I am signing this object: