4. Sensitivity Measurements
The sensitivity of the ladder two-element and four-element matches with the 7x7 mm dual band EFR32MG1 series is compared in the
table below. Here, 20 byte long standard ZigBee
®
packages are used and 1 % PER sensitivity is shown. The measurements were
made at room temperature. More sensitivity data can be found in
Table 4.1 on page 16
.
The applied setup includes the WSTK motherboard and the BRD41XX type development boards with different match types. The
BRD41XX type boards apply a UFL RF connector and a UFL-SMA transition. These two elements cause approximately 0.5 dB addi-
tional attenuation. The RX sensitivity results shown are already compensated for by this error. The frequency is 2.405 GHz, i.e., the first
Zigbee channel.
These RX test results are done on a very limited number of samples and are typical. Large test sample sensitivity results are only avail-
able for the 7x7 mm dual band package with a four-element lumped element match and are provided in the data sheet.
Table 4.1. Measured Sensitivities of the Ladder Two-Element and Four-Element Matchings Using Standard 20-Byte ZigBee
Packages (After UFL Connector Compensation)
Package Type
Matching Type
Sensitivity [dBm]
7x7 mm, 48-pin, Dual Band
Ladder 2-Element
–99.1
Ladder 4-Element
–98.5
The Rx test conclusions are as follows:
1. The Rx sensitivity variation resulting from the different package versions is lower than 1 dB and typically 0.5dB (see
Appendix
2.1 Measured TX Emission
).
2. The low-power reduced element matches have approximately 0.2–0.5 dB better sensitivity compared to their high power counter-
part. In other words, two-element vs. four-element ladder match, or two-element minimum BOM vs. Tline minimum BOM match.
AN930: EFR32 2.4 GHz Matching Guide
Sensitivity Measurements
silabs.com
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