3 June 2011

Avago debuts integrated switch & LNA modules for TD-SCDMA and TD-LTE base-stations

Avago Technologies has launched a series of high-power switch low-noise amplifier (LNA) modules for use in front-end receiver designs of TD-SCDMA and TD-LTE base transceiver station (BTS) applications.

The small-footprint ALM-12x24 modules replace existing three-piece discrete solutions, providing significant board-space savings (especially critical for BTS designs with eight 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, says Avago. The modules deliver what is claimed to be best-in-class noise performance, high gain and high linearity from a compact package.

Avago's new modules integrate a high-power 50W single-pole, double-throw (SPDT) switch, a first-stage LNA and a second-stage high-linearity amplifier in a lead-free 8mm x 8mm package (with 50dB isolation between the first- and second-stage amplifiers, enabling external addition of an attenuator or RF filter without affecting the overall module performance). Constructed with an Avago low-distortion silicon PIN diode, the SPDT switch prevents the LNA from being damaged 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 firm’s proprietary 0.25µm GaAs enhancement-mode pHEMT process to achieve robust RF performance.

According to Avago, 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, it adds. 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. The ALM-12124 module covers 1880–2025MHz with 0.80dB NF and typical linearity performance of 36.4dBm output third-order intercept (OIP3) at 1900MHz in receiver mode. The ALM-12224 module covers 2300–2400MHz with 0.99dB NF and 38.5dBm OIP3 typical performance at 2400MHz in receiver mode. The ALM-12x24 modules also have a high power-handling capability of 47.5dBm.

The ALM-12x24 switch LNA modules ship in a 24-pin MCOB package. The ALM-12124 and ALM-12224 modules are priced at $8.58 each in 10,000-piece quantities.

Avago is exhibiting the modules, along with its complete RF and Microwave portfolio, at the 2011 IEEE Microwave Theory & Techniques Society (MTT-S) International Microwave Symposium (IMS) in booth number 1602 at the Baltimore Convention Center, Baltimore, MD, USA (7–9 June).

Tags: Avago LNA modules GaAs enhancement-mode pHEMT

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