CST software helps analyse RF coexistence in mobile handsets

The design of wireless technologies such as mobile phones is becoming increasingly complex with the need to consider a variety of RF systems such as multi-band cellular antennas, WiFi, Bluetooth, NFC and navigation systems (GPS and GLONASS). As multiple RF systems often coexist within one device, cosite interference effects needs to be considered in the design process.

The first two systems both transmit and receive signals, while the GPS system is simply a receiver. The phone model is for demonstration purposes only and does not represent any real product. The phone model is created in CST STUDIO SUITE, a 3D EM simulation tool containing full-wave solvers. The model includes the antennas for the three systems of interest, and farfield monitors at key operating frequencies of the different systems. A simulation is then carried out using the time domain solver across the spectrum from 0-6GHz. This simulation provides both the
S-parameters, which illustrate the wideband coupling (isolation) between each antenna, and the farfield patterns, giving the pattern degradation caused by installing the antennas in the environment of the handset. GPU acceleration can be used to improve the performance of the simulation.

Once all of the results have been calculated, the data can be transferred to EMIT using the “Export to EMIT” macro in CST STUDIO SUITE. This saves all of the S-parameters, the field patterns and the CAD data in a single directory, which can then simply be opened directly in EMIT.

Download and read the full CST application note, below.