GUI V2.0 demonstrating 3-D visualization of iSAR HEAD: last sample measurement (left), reference phone (middle) and match of amplitude (correlated with RF antenna input power) and of pattern (correlated with QA in production).
GUI V2.0 visualizing results obtained with iSAR² FLAT as well as the input windows for CMU200 and Python Window.
iSAR² systems evaluate SAR under the same conditions or similar conditions that comply with the Fast SAR requirements of IEC 62209 II and IEEE1528(2009). Despite certain limitations of the phantom and measurement grid, such as limited size / shape, fixed resolution (that can be enhanced by the combiner), neglected z-component, measurement in only one plane (4\,mm below the surface), the obtained results closely correlate to the measurements obtained with the most precise DASY5scanner. The accuracy limitations resulting from the fixed measurement resolution are easily overcome by combining multiple measurements at different orientations (ref. section 3.3). An extensive study showed excellent agreement between the results of iSAR² and DASY5.
iSAR² supports pre-compliance testing and substantially reduces compliance testing time:
iSAR Flat allows for testing according to IEC 62209 II. A 2 mm shell thickness and broadband absorbing material simulating head tissue parameters are equivalent to the flat phantom conditions. A set of low loss spacers (1, 2, 5, 10, 15 mm or any other size available upon request) ensures the required separation between the surface and phone.
iSAR Flat (Muscle) is filled with a broadband absorbing material simulating muscle tissue parameters for testing in accordance with FCC OET Bulletin 65 Supplement C.
iSAR Head is filled with head tissue simulating material and corresponds to the ear-mouth line of IEEE-1528, IEC 62209 II, FCC OET 65 C, etc. This line is extruded in an orthogonal direction, resulting in a 2 mm thick cylindrically shaped shell with an ear spacer. A set of masks representing different angles (6, 15 degrees or any angle available upon request) is available.
Traditional scanners require very specialized DUT software for evaluating transmitters with spatial diversity properties, since they measure time sequentially. Special software for the DUT is not required with the iSAR² systems, since the entire absorption pattern is measured within the same (user-defined) time integral. Therefore, in addition to the true SAR values, important information about the DUT performance in loaded conditions can be compiled with the iSAR² systems.
Modern multi-band devices require multiple tests for a complete SAR evaluation. To reduce the testing time, IEC 62209 II explicitly allows the usage of fast SAR systems such as the iSAR². Worst-case frequencies and operating modes can be identified easily and quickly.
In addition to the very short time duration of single tests, the software also automatically runs sequences supported by a base station simulator. Programming of frequencies and bands of an R&S CMU 200 is shown in the figures above.
Small changes in the RF relevant parts can significantly affect the SAR level. The influence of the antenna design or layout, antenna or ground contacts, shields, or material changes on the SAR can be investigated quickly and efficiently . In the quality control process, for example, production deviations that influence the RF radiation (power or pattern) can be reliably identified. Due to the short measurement time and automation capabilities, it is even possible to test each device individually.
SAR is proportional to the emitted power of a device. For a given geometry and arrangement relative to the iSAR², the relative power can be measured with high precision. Each sensor is calibrated precisely over the full dynamic range for the chosen communication system modulation.
Stability issues causing variations in the output power can be easily investigated with the time sweep function (ref. 5.5.5) (--> time sweep graphics missing). Long-time evaluations of stability or battery drainage can be documented graphically. Numerical values are available.
Remote control of the iSAR² without the GUI using customer specific programs is possible. The Python interpreter also provides access to extended automation.
Further specific control of the measurement interval is possible by providing a logical gate or trigger signal (ref. 2.1). Synchronization without an operator allows for highly automated applications. Customer specific solutions for integration into specific automated environments are possible.
The software is designed such that SPEAG can quickly integrate the system into any 3rd party applications.
The functionality of iSAR² as described above, when combined with OTA evaluations, provides everything necessary to evaluate the performance of DUTs when operating close to the human body. SPEAG also offers various high-end phantoms for OTA usage such as the standardized OTA phantoms, or phantoms mimicking the load of iSAR².