ST AN5622, B-UWB-MEK1 User Manual
AN5622
Application note
B-UWB-MEK1 antenna offset adjustment
Introduction
B-UWB-MEK1 boards have an SMA connector as UWB output. The module is calibrated so that the distance measure starts at the SMA output.
When plugging an antenna with a connector, this reference point changes and offsets the distance measurement. Therefore, the system must take into account specific offset values, which depend on the antenna and connector types.
The B-UWB-MEK1 standard and extension kits are delivered with omnidirectional antennas and SMA male male connectors. The offset for this configuration is 31 cm. This is the default value in MOD1/MEK1 programming tool applied to each board.
This application note complements the information available in the SDK. It is intended for advanced users already familiar with the quick start guide. It is based on system version 3.x.
Figure 1. B-UWB-MEK1 board with an omnidirectional antenna
Omni-directional antenna 
SMA male-male connector
UWB output
AN5622 - Rev 1 - April 2021 |
www.st.com |
For further information contact your local STMicroelectronics sales office. |
|
|
|
AN5622
General information
1General information
B-UWB-MEK1 embeds the B-UWB-MOD1, which features the STM32L476JE 32-bit microcontroller based on the Arm® 32-bit Cortex® M4 processor.
Note: |
Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. |
|
Definitions |
|
Table 1 presents the definition of acronyms that are relevant for a better understanding of this document. |
|
Table 1. List of acronyms |
|
|
Term |
Definition |
|
|
3D_SELF |
3D single self-positioning |
|
|
BLR |
Beacon-listening rate |
|
|
HF |
Hyperframe |
|
|
PHS |
Protocol hyperframe size |
|
|
PSN |
Protocol slot number |
|
|
PSS |
Protocol slot size |
|
|
RTLS |
Real time locating system |
|
|
RV |
Rendez-vous (slot and zone) |
|
|
SF |
Superframe |
|
|
SFI |
Superframe information |
|
|
TDMA |
Time-division multiple access |
|
|
UWB |
Ultra-wideband |
|
|
References
Refer to the following documents for an introduction to the B-UWB-MEK1 and B-UWB-MOD1 products in indoor location systems:
•Ultra-wideband module for high-precision indoor location (DB4404)
•Evaluation kit for the B-UWB-MOD1 ultra-wideband module (DB4392)
•B-UWB-MEK1 quick start guide (UM2798)
•SDK advanced documentation
Demonstration software
Contact the local STMicroelectronics sales office or distributor (refer to www.st.com) for the latest software and associated documentation.
AN5622 - Rev 1 |
page 2/10 |
|
|
AN5622
Offset adjustment
2Offset adjustment
2.1Find the offset
Table 2. Find the offset
|
Component |
|
Offset (in cm) |
|
||||
|
Ch1 |
Ch2 |
|
Ch3 |
|
Ch4 |
||
|
|
|
|
|
||||
|
|
|
|
|
|
|
|
|
|
Omni-directional with |
|
26 |
31 |
|
27 |
|
37 |
|
original SMA connector |
|
|
|
||||
|
|
|
|
|
|
|
|
|
Antenna |
|
|
|
|
|
|
|
|
Directional with |
|
|
|
|
|
|
|
|
|
|
29 |
37 |
|
26 |
|
50 |
|
|
original connector |
|
|
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
SMA male male |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Additional |
SMA female male right |
|
|
|
3 |
|
|
|
connector |
angle |
|
|
|
|
|
||
|
|
|
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
Attenuator |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Average factor |
Offset of |
Real cable length (in cm) × 1.49 |
|||||
|
|
|
two SMA |
|||||
Cable |
|
|
wire male |
|
|
|
|
|
|
|
Group delay (in s) × C (in m.s-1) × 100 |
||||||
|
Measurement on a network vector analyzer |
connectors |
||||||
|
included |
|
(C = 299 792 458 m.s-1) |
|
||||
|
|
|
|
|
||||
|
|
|
|
|
|
|||
AN5622 - Rev 1 |
page 3/10 |
|
|
Loading...