Avago Technologies Debuts Fail-Safe Bypass Low-Noise Amplifier Modules for Cellular Infrastructure Applications
Avago Technologies announced a series of fail-safe bypass low-noise amplifier (LNA) modules for tower mounted amplifiers (TMA) and base transceiver stations (BTS) applications. The new ALM-11x36 LNAs deliver best-in-class noise performance and high linearity with a compact package. The modules can replace large discrete and surface-mount component counts in conventional designs, shortening design cycle time and providing board space savings.
The Avago ALM-11x36 LNA modules have low noise and high linearity achieved through the use of the company’s proprietary 0.25 um GaAs Enhancement-mode pHEMT process. Their superior bypass isolation eliminates the possibility of oscillation issues, and the modules also feature low bypass insertion loss and high input and output return loss. In addition, the ALM-11x36 LNAs are equipped with a fail-safe bypass function, which is especially critical for TMA applications to enable the LNA bidirectional bypass path during the absence of DC power supply.
All matching components are fully integrated within the modules and the 50 ohm RF input and output pins are already internally AC-coupled. This makes the modules easy to use, as the only external parts required are DC supply bypass capacitors. The LNAs deliver optimum performance across a wide range of bands, with the ALM-11036 module covering 776-870 MHz, the ALM-11136 module covering 870-915 MHz, the ALM-11236 module covering 1710-1850 MHz and the ALM-11336 module covering 1850-1980 MHz. All the modules share the same compact 7.0 by 10.0 by 1.5 mm package and pin out configuration, and are thus ideal for common platform designs.
The wireless infrastructure industry must provide optimum coverage with the best signal quality in a crowded spectrum. Receiver sensitivity is the most critical requirement in a BTS receiver’s design, and LNA selection greatly affects the receiver’s performance. For front-end design architectures with a bypass path, low noise figure (NF) and bypass insertion loss (IL) are the key design goals. Another key design factor is linearity, which affects the receiver’s ability to distinguish between wanted and spurious signals that are closely spaced. Input third-order intercept, IIP3, is used to specify linearity. The ALM-11x36 LNA modules are equipped with superior performance as follows:
· ALM-11036 – 0.78 dB NF, 0.82 dB bypass IL and 21.3 dBm IIP3 (Typical at 849 MHz, 5V and 92 mA)
· ALM-11136 – 0.76 dB NF, 0.85 dB bypass IL and 22.0 dBm IIP3 (Typical at 915 MHz, 5V and 92 mA)
· ALM-11236 – 0.67 dB NF, 0.75 dB bypass IL and 17.3 dBm IIP3 (Typical at 1785 MHz, 5V and 99 mA)
· ALM-11336 – 0.72 dB NF, 0.78 dB bypass IL and 17.9 dBm IIP3 (Typical at 1980 MHz, 5V and 100 mA)