This AI-assisted article was approved by Volker Cesinger. It presents his personal perspective and is not an official Checkpoint Systems publication.
- Define quantity
- Check reference
- Compare levels
- Test complete system
| Power level | Milliwatts | Relative required power |
|---|---|---|
| −20 dBm | 0.01 mW | 100 % |
| −23 dBm | 0.005012 mW | 50.12 % |
A new chip is promoted with a lower sensitivity threshold. Is that better, and does it mean more range? The first question can be answered for the same measured quantity. The second requires the complete setup. I would compare datasheets only after clarifying units, reference point and test conditions.
dBm describes a power level
dBm expresses power relative to one milliwatt. Zero dBm equals one milliwatt. Negative values are not negative energy; they describe power below that reference. A synthetic calculation: −20 dBm equals 0.01 milliwatts or 10 microwatts; −23 dBm is approximately 5 microwatts.
For chip read sensitivity expressed as minimum required power, a more negative value means that the chip can respond with less supplied power under the stated test conditions. Transmit power and sensitivity are different quantities. A negative sensitivity figure is not an instruction to configure the reader to that value.
dB describes a difference
The difference between −20 and −23 dBm is 3 dB. The second power level is approximately half the first. For power, the level in dBm equals 10 × log10(power in milliwatts). Applying the logarithmic expression to the ratio of two powers gives dB instead of dBm.
This example is mathematics, not a comparison of two real products. Even a statement such as 3 dB better sensitivity needs a reference, the same quantity and comparable conditions. A standalone claim of improvement by −3 dBm is insufficient for a meaningful assessment.
Why it does not specify a fixed range
A chip does not operate independently of its antenna and object. Label construction, orientation, packaging, neighbouring goods, permitted reader configuration and the return signal all belong to the radio link. Better chip sensitivity may create additional margin; it guarantees neither a specific extra distance nor improved read-zone boundaries.
Additional detection may even be unwanted. If goods in the next aisle now respond too, improved readability has exposed a filtering or zoning requirement. Range alone does not establish whether the process has become more reliable.
Making a datasheet comparison useful
- Do not equate read sensitivity with write sensitivity.
- Distinguish chip figures from measurements on a finished label.
- Record frequency, setup and the reference for supplied power.
- Check intended objects alongside unwanted neighbouring reads.
- Keep a reference setup and investigate one change at a time.
Checkpoint presents UCODE X as a new chip generation for its labels. Assessment still depends on the actual measured quantity and complete construction. A better chip figure does not guarantee finished-label range; inlay and packaging remain part of the comparison.
Next step
For two offers, first record the quantity, unit and reference. Then plan a comparable range trial or examine antennas and read zones. That turns a better number into a testable technical decision.
Sources
- Checkpoint: UCODE X and RFID performance, the chip generation within label construction.
- RAIN System Design Guidelines, system perspective and link budget.