Avago Technologies has announced a series of high-power switch low-noise amplifier (LNA) modules dedicated for use in front-end receiver designs of TD-SCDMA and TD-LTE base transceiver station (BTS) applications. The new small-footprint ALM-12×24 modules replace existing three-piece discrete solutions, providing significant board space savings that is especially critical for BTS designs with 8 transceiver channels in a single radio card. The fully-matched solutions also shorten design cycle time by eliminating the need for tuning with external matching circuitry. The modules deliver best-in-class noise performance, high-gain and high linearity from a compact package.
The Avago ALM-12×24 LNA modules integrate a high-power 50W Single Pole, Double Throw (SPDT) switch, a first-stage LNA and a second-stage high-linearity amplifier in an 8-mm-by-8-mm package. Constructed with an Avago PIN diode, the SPDT switch prevents the LNA from damage by high-power signals potentially leaking over from the transmit chain in conditions where the antenna is mismatched. The LNA and high-linearity amplifier leverage the company’s proprietary 0.25 um GaAs Enhancement-mode pHEMT process to achieve robust RF performance. Avago will exhibit the modules, along with its complete RF and Microwave portfolio, at the 2011 IEEE Microwave Theory & Techniques Society International Microwave Symposium in booth number 1602 at the Baltimore Convention Center from June 7-9.
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, low noise figure (NF) is a key design goal. Another key design factor is linearity, which affects the receiver’s ability to distinguish between wanted and spurious signals that are closely spaced. Output third-order intercept (OIP3) is used to specify linearity. The ALM-12124 module covers 1880-2025 MHz with 0.80 dB NF and 36.4 dBm OIP3 typical performance at 1900 MHz in receiver mode, while ALM-12224 module covers 2300-2400 MHz with 0.99 dB NF and 38.5 dBm OIP3 typical performance at 2400 MHz in receiver mode.