Infineon Technologies AG

Infineon Supports LTE-A LNA Customers With Band-Specific Application Notes

Company Profile

Infineon Technologies AG is a German semiconductor manufacturer spin off of Siemens AG. The company has more than 50 years of experience in developing RF devices for a wide range of wireless applications, leading the market with high-performance, yet cost-effective products. To support its customers, Infineon developed a solution finder tool that provides easy access to the application notes, datasheets, device models, and evaluation boards that help designers quickly and easily identify the right product for the right application.

The Design Challenge

The complexity of mobile phone design has increased significantly in order to support higher data rates and more functionality, while the window for bringing new devices to market has decreased from years to months. Consequently, phone manufacturers require microwave semiconductor vendors to offer highly integrated devices with linear performance.

LNAs that are located in the antenna paths of the phone improve the system noise figure on the receive path, enabling increased data rates nearly double that of solutions without LNAs, especially under very weak signal strength. Infineon LNAs have high linearity, which assures optimal signal reception even with poorly isolated antennas and losses between antennas and transceivers. In addition, their extremely low noise figure enhances the sensitivity of the RF modem by about 3 dB, offering system layout flexibility by suppressing noise contribution from losses of signal lines and the surface acoustic wave (SAW) filters, as well as the receiver.

To deliver best-in-class linearity and noise-figure performance, Infineon designers rely on the robust, accurate circuit simulation and precise modeling of all the components used in their MMIC and module designs, including printed-circuit board (PCB) test boards. Precise linear models enable faster verification of system-level performance for the application circuits supporting different bands of 4G LTE-A, currently numbering more than 44 LTE bands worldwide. By using powerful scripting capabilities built into NI AWR Design Environment™, the time for designing and documenting new application circuits has been reduced from days to hours.

The Solution

Infineon chose NI AWR software for its exacting device modeling needs, which at the application level begin with the characterization of the printed circuit board (PCB) used for LNA/module measurements. The LNA and LNA/multiplexer PCB test structure include an RF input and output transmission line of predefined length and width. S-parameter and noise figure measurements of any device at the calibrated test equipment port will include this transmission line, as well as the SubMiniature Version A (SMA) connector launches on the test boards input/output. The response of the test structure can be removed from the measurement through de-embedding, resulting in a more accurate measurement of the isolated device response. The test structure can be characterized through a variety of measurement-based methods or rigorous electromagnetic (EM) simulation. In this case, engineers used the closed-form transmission line and SMA models in NI AWR Design Environment, specifically Microwave Office circuit design software, to compare to three different calibration standards: namely a short, open, and through transmission line.

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To view related video, click >> LTE-A LNA Application Circuits