IndieRF Notes

Engineering notes you can check by hand

Short, reference-plane-honest writeups on RF math, traces, and the limits of the models. Built next to the workbench, not as a marketing blog.

All dB ENIG filter mental-math microstrip noise plating s2p sparam temperature Touchstone trace

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Mental Math for RF Engineers: Calculating dB, Power, and Bandwidth on the Fly
Aug 27, 2026 · 4 min
Convert dB to power, estimate kTB from bandwidth, and avoid the 10log versus 20log error with a small set of dependable RF shortcuts.
dB · noise · mental-math
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ENIG vs Bare Copper: Why Nickel Adds Microstrip Loss
Aug 30, 2026 · 4 min
On 50 Ω RO4350B microstrip at 10 GHz, ENIG adds about 0.31 dB/in over bare copper. The gold is a flash. The nickel is thicker than a skin depth. Change the finish in Transmission Line Calculator and read the loss.
microstrip · ENIG · plating · trace
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S-parameter Viewer: Overlay Touchstone Files and Score KPIs
Sep 6, 2026 · 5 min
Drop .s2p, .s1p, or MDIF into S-parameter Viewer for log-mag, phase, VSWR, group delay, kind-aware KPIs, and part-to-part stats. Mini-Circuits BFCG-252+ files are the worked example, not the subject.
sparam · Touchstone · s2p · filter
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S-parameter Viewer: Temperature Δ for Worst-Case Analysis
Sep 6, 2026 · 5 min
Drop Plus25DegC / Minus45DegC files into S-parameter Viewer and Analysis opens Temperature — Δ vs frequency and the selected quantity vs T at the marker. A +25°C typical is not the cascade corner. Mini-Circuits EQY-2-63+ files are the worked example.
sparam · Touchstone · s2p · temperature