EMC Toolbox
38 free calculators and CISPR 32, MIL-STD-461 and IEC 61000-4 summaries for EMI/EMC and RF engineers
Popular calculators
dBm ↔ Watt Power Converter
Convert between dBm, mW and W. 0 dBm = 1 mW and 30 dBm = 1 W.
dB & Unit ConversiondBµV/m ↔ V/m Field Strength Converter
Convert field strength between dBµV/m, mV/m and V/m so you can compare emission limits with immunity test levels.
dB & Unit ConversiondBm ↔ dBµV Converter (with Impedance)
Convert between dBm and dBµV for a given impedance. At 50 Ω, dBµV = dBm + 107.
RF & Transmission LinesVSWR ↔ Return Loss ↔ Reflection Coefficient
Convert between VSWR, return loss, reflection coefficient and mismatch loss. Edit any field and the others update.
RF & Transmission LinesAntenna Factor (AF) ↔ Antenna Gain
Convert between antenna factor (AF, dB/m) and antenna gain (dBi) at a given frequency (50 Ω, free space).
Testing & MeasurementMeasured Voltage → Field Strength (dBµV/m)
Field strength in dBµV/m from receiver reading, antenna factor, cable loss, attenuator and preamp gain.
Testing & MeasurementTest Distance Conversion (Limit 3 m ↔ 10 m)
Convert limits or readings between test distances. 10 m → 3 m is about +10.46 dB.
Testing & MeasurementRadiated Immunity Required Power (V/m → W)
Estimate the amplifier power needed for radiated-immunity testing from target field, distance and antenna gain, including 80 % AM.
Calculators by category
dB & Unit Conversion
dBm ↔ Watt Power Converter · dBµV ↔ Volt Converter · dBµV/m ↔ V/m Field Strength Converter …
RF & Transmission Lines
VSWR ↔ Return Loss ↔ Reflection Coefficient · Free-Space Path Loss & Friis Received Power · Frequency ↔ Wavelength (with λ/2, λ/4) …
Testing & Measurement
Measured Voltage → Field Strength (dBµV/m) · Test Distance Conversion (Limit 3 m ↔ 10 m) · Combined & Expanded Uncertainty (RSS) …
Shielding & Filters
Shielding Effectiveness / Insertion Loss from Readings · Skin Depth & Absorption Loss · RC Low-Pass Filter Cutoff & Attenuation …
Standards summaries
CISPR 32
Structure of CISPR 32 (EN 55032), Class A vs B, radiated and conducted limit tables, test setup and practical checkpoints.
CISPR 11
Scope of CISPR 11 (EN 55011) for industrial, scientific and medical (ISM) equipment, the Group 1/2 and Class A/B classification, measurement methods and how it differs from CISPR 32.
MIL-STD-461
Overview of MIL-STD-461G: the 19 test method codes (CE/CS/RE/RS), how requirements are applied, setup elements and typical emission/susceptibility test flow.
IEC 61000-4-x
Overview of the IEC 61000-4 series (ESD, radiated RF, EFT, surge, conducted RF, magnetic field, voltage dips): test concepts, representative levels and performance criteria.
Practical guides
What to Check When Radiated Emissions Exceed the Limit
A practical step-by-step guide: verify the measurement, infer the cause from the frequency pattern, check cable influence and prioritise countermeasures.
7 Common Mistakes in dB Conversions
Seven recurring errors when handling dBµV, dBm, dBµV/m and uncertainty in EMC data, each with the correct calculation and numerical examples.
Self Pre-Compliance Checklist Before an Emission Test
A checklist covering EUT configuration, instrument settings, environment, measurement procedure and records before a formal emission test.
EMI receiver vs spectrum analyzer: what is the difference?
Differences between an EMI receiver and a spectrum analyzer (detectors, bandwidth, overload tolerance, preselector) and cautions when using an analyzer for pre-compliance.
Conducted emission testing and LISN basics
Purpose of conducted emission testing on power lines, what a LISN does (fixed impedance and noise isolation), the 150 kHz–30 MHz range, and grounding and layout cautions for pre-compliance.
ESD testing (IEC 61000-4-2): practical tips and countermeasures
Choosing contact versus air discharge, coupling planes (HCP/VCP), stepping through test levels, pass criteria and board-level countermeasures (TVS, grounding, layout).
What an EMC test plan must contain
A checklist of items for a test plan: sample configuration, operating modes, applicable standards, pass criteria and cable layout.
Choosing a ferrite bead and a common-mode choke
How to choose ferrite beads and common-mode chokes by impedance at the problem frequency, rated current and DC bias, self-resonant frequency and saturation.
Glossary
Key EMI/EMC terms in Korean and English. 116 terms
Why you can rely on it
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Self-written summaries
Standards summaries are written in our own words and list only values that agree across several sources.