Project Examples

Project examples for system engineering and modeling. Past services have included RF and optical link budgets, optical fiber characterization such as polarization mode dispersion (PMD) measurements, OTDR, and DWDM attenuation versus wavelength, ionospheric HF communications modeling of reliability and latency,  and availability modeling for millimeter-wave (MMW) links and Free Space Optics (FSO). Read more here…

System Engineering & Modeling

Visibility statistics for London converted to attenuation statistics in dB/km loss. Crunched data was 5 minute visibility from Heathrow Airport. This data can be used for Free Space Optics (FSO) link budgets to determine things like link availability versus link distance given the FSO terminal specifications.

Broadband Wireless–Financial Analysis


Financial analysis for a particular outdoor broadband wireless deployment assuming certain monthly subscription fees, market penetration, base station density, capital, and recurring network expenses (ROI = Return on Investment).

RF Loss Through Trees


Example RF Loss versus tree depth at various frequencies. Exact loss coefficients will depend on the tree type and density (evergreen, deciduous, wet evergreen forest, etc.).

HF Communications Modeling


Example modeling of ionospheric HF propagation reliability as a function of frequency, time of day, season, and year. Not shown: corresponding point-to-point latency modeling outputs and measurements.

Modeling of Ice Attenuation on Antenna Radome


Attenuation verses antenna radome ice thickness was calculated based on the measured complex permittivity of ice at various microwave frequencies.

Optical Fiber Link Budgets


Optical fiber link budget that automatically reads measured attenuation, chromatic and polarization-mode dispersion as a function of wavelength. Spreadsheet also allows inclusion of measured splice or connector losses, and laser/modulation types to be included for the power and rise-time link budgets.

Optical Fiber Chromatic Dispersion Measurements


Measured chromatic dispersion as a function of DWDM wavelengths and curve fit of dispersion versus wavelength to be used in the fiber link budget.

Optical Fiber PMD Measurements


Optical fiber Polarization Mode Dispersion (PMD) measurements. Older installed optical fibers may not have a PMD specification, in which case it is necessary to measure the PMD to ensure the fiber segment can support higher modulation rates. In this project, fiber PMD was measured as preparation for a network upgrade to OC-192, where we tagged individual fibers that would not be able to support OC-192 (10 Gbps) due to an excessive PMD.

Measured PMD Statistics


PMD statistics for a service provider's fiber-optic network. Note that some optical fibers in this network were over 15 years old, which accounts for the larger PMD values.

Maximum Fiber Distance vs. PMD


Calculated maximum fiber distance vs. Polarization Mode Dispersion (PMD) and data-rate (assumes no external PMD compensation).

Lab Simulation of Microwave Fading


A lab simulation was implemented using a voltage controlled variable attenuator driven by a function generator to create arbitrary fade events to assess switching performance in a protected SONET ring.

HF Antenna Design & Modeling

7 MHz antenna designed for a limited space environment using finite element modeling.

3D HF Antenna Pattern

Antenna pattern assuming actual ground conductivity at 7 MHz for previously shown antenna design.

2D HF Antenna Elevation Pattern

Plot shows the bi-directional gain and radiation angle for a 7 MHz HF antenna design.

Satellite Ground Station Noise Measurements

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Violet areas are near-line-of-sight regions common to the suspected noise source and the Satellite ground station, which experienced more noise when pointed in the Azimuth direction of a hydroelectric dam.