FPC1000 is an economical spectrum analyzer from Rohde&Schwarz, which can provide customers with detection and decoding functions for Bluetooth Low Energy (BLE) and Tire Pressure Monitoring (TPMS) devices.

Bluetooth Low Energy (BLE) devices use a total of 40 channels, including 3 broadcast channels (37, 38, 39) and 37 data packets sent on channels 1 to 36. The link layer packet consists of four parts, as shown in the following figure:

After the design of the Bluetooth low-power transmission module is completed, it is necessary to verify the correctness of the data information it sends. Therefore, testing the data structure, output power, modulation characteristics, and frequency error of Bluetooth low-power transmitters is an important part of product production.

Introduction to Tire Pressure Monitoring and Testing Requirements

The Tire Pressure Monitoring System (TPMS) for automobiles is a warning system that automatically detects tire pressure and temperature, and alerts for abnormal tire conditions. The signals of tire pressure monitoring equipment are mainly FSK and ASK standards. Due to the characteristics of car warning and safe driving, it is particularly important to test the signal quality, power, modulation characteristics and other indicators of the tire pressure monitoring equipment transmitter to ensure its accuracy in order to truly achieve the function of safety warning.

Rohde&Schwarz Solution

The cost of Bluetooth low-power and tire pressure monitoring products is very low, so economical spectrum analyzers are more suitable as testing equipment for such products. The FPC1000 spectrum analyzer from Rohde&Schwarz has excellent RF performance and cost-effectiveness compared to similar instruments, making it suitable as a price sensitive Bluetooth low-power and tire pressure monitoring transmitter testing instrument.

Main parameters:

➤Frequency range: 5KHz to 1GHz/2GHz/3GHz

➤Excellent RF performance: in the 2G~3GHz frequency band, the typical bottom noise can reach -165dBm (pre release)

➤Resolution bandwidth (-3dB): 1Hz to 3MHz

➤Support AM, FM, ASK, FSK signal analysis

➤High resolution: 10.1-inch GA (1366 * 768 pixels) monitor

➤Remote control and measurement software supports Wi Fi connection

application

During actual testing, the tested device can be connected to the FPC via a cable or tested through an antenna.

Validate data structure

From the FPC parsing result symbol display interface, you can see the data content inside different data packets. As shown in the figure below, the first 8 bits are the preamble, 32 bits are the access address, 16 bits are the header, and the last 24 bits are the CRC check. The symbols can be used to determine whether the transmitter meets the design standards.

Modulation signal and eye diagram

In the modulation deviation mode of FPC, parameters such as frequency deviation, carrier power, carrier frequency offset, and modulation error of the modulation signal can be displayed in the spectrum mode. At the same time, the FPC can also display the eye diagram of the tested signal, which can quickly check the signal quality,

summary

Based on the Rohde&Schwarz signal and spectrum analyzer FPC, Bluetooth low-power and tire pressure monitoring transmitter signal quality testing can be easily completed. Meanwhile, FPC can also support measurement of standard modulation signals such as AM, FM, ASK, and FSK.