Modern vehicle key systems, such as remote keyless entry (RKE) and passive entry/passive start (PEPS) systems, use a variety of wireless communications standards to transmit encoded signals. In the past, both LF frequencies (e.g. 125 kHz) and UHF frequencies (e.g. 433 MHz) as well as a magnetic compass system that works in three spatial axes (e.g. 21 kHz) were used to locate the key in or near the vehicle.
Using ultra-wideband (UWB) radio, the latest generation of key systems only needs one wireless standard in the non-licensed frequency range between 3.1 and 10.6 GHz. Time of flight (TOF) measurement prevents the relay attacks used to steal vehicles. TOF also makes it possible to determine the location of the key. Some manufacturers use near-field communications (NFC) to use a smartphone as a digital key.
Rohde & Schwarz is showing how a new system solution can help manufacturers meet their testing requirements. The demonstration consists of a fully automatic R&S TS7124AS shielded test box that provides an interference-free environment for testing devices. The box is equipped with an application-specific DUT mount and adapted antenna systems.
The central unit is the R&S CompactTSVP PXI-based test system with an optional embedded CPU. The system manages the precise supply of power to the DUT and measures the supply currents in the various operating modes, even time-synchronized to RF bursts from UWB signals. The system also handles wireline DUT communications such as LIN, CAN, I ²C and SPI.
An R&S FPS spectrum analyzer evaluates RF signals in the frequency and time domain. A Helmholtz magnetic coil and corresponding 3D magnetic field power generator are used to test and calibrate magnetic compass systems. The solution also includes powerful software packages to control test sequences and manage the collected measurement data.
Rohde & Schwarz; www.rohde-schwarz.com