Measured radio wave of LoRa (920Mz band: LPWA)

By using the signal analyzer MSA500 series, the signal of LoRa (LPWA using 920MHz band) will be acquired.

Application

We received such an inquiry as “Can be measured the LoRa signal using the MSA500 series ?” and then measured it actually.
LoRa is one of LPWA (Low Power Wide Area) using the 920 MHz band, and the origin of the name comes from “Long Range”. It can communicate at a maximum of several tens of kilometers, and features low power consumption.
The LoRa signal adopts a special modulation scheme called chirp spread spectrum. Although the amplitude is constant and the frequency is changed, instead of transmitting 0 or 1 by high or low of the frequency as in ordinary PSK, 0 or 1 is transmitted using a signal (chirp signal) whose frequency continuously varies. The signal is transmitted by combining a signal of frequency becoming high (up chirp) and a signal of frequency becoming low (down chirp).

Solution

Comparison of sweep type spectrum analyzer MSA400 series and real-time spectrum analyzer MSA500 series

Display of frequency vs. time

By displaying the frequency vs. time it is possible to observe the frequency bandwidth and transmission time of the chirp signal.
The following items can be measured in addition to the above.

• Occupied bandwidth
• Permissible deviation of frequency
• Strength of unwanted emission
• Antenna power Adjacent channel leakage power
• Radio waves emitted by the secondary
• Transmission time

System constitution

Handheld signal analyzer [MSA538]

Portable antenna [M401]

MICRONIX Corporation reserves the right to make changes in design, specification and other information without prior notice.

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