STM32W108B-SK STMicroelectronics, STM32W108B-SK Datasheet - Page 3

• Manufacturer Part Number: STM32W108B-SK
• Description: STARTER KIT FOR STM32W108
• Manufacturer: STMicroelectronics
• Series: STM32r
• Type: MCUr

Specifications of STM32W108B-SK

• Featured Product: STM32 Cortex-M3 Companion Products
• Contents: Board
• Silicon Manufacturer: ST Micro
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: STM32
• Silicon Family Name: STM32W108xx
• Kit Contents: Board
• Features: IEEE
• Mfg Application Notes: STM32W108 Adjacent Channel Rejection Measurements
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: *
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

AN3218
Interferer waveforms
Figure 1.
Comparison of spectra, 25 MHz span
It can be seen that the heavily filtered 15.4 signal generated by the signal generator is not
representative of either type of modulation technique, and therefore does not give a useful
measure of real performance.
At 10 MHz there is a difference between the two modulation methods of about 10 dB. This
means that the vector-modulated signal could show a better ACR if the receiver's own
rejection is high enough. However, quoted alternate channel measurements should still use
an ideal signal since a system designer cannot know what type of transmitter is used in the
interfering node(s).
Note that the standard specifies using an 802.15.4 signal of pseudo-random data for the
interferer. This is not the same as using a signal generator to generate an MSK signal with
pseudo-random chips, although the effect on ACR is small. The difference between random
MSK chips and random 15.4 symbols is the dip in the spectrum at 0 Hz offset.
Doc ID 17543 Rev 2
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