Analog Devices introduced a two-chip IF (intermediate frequency) receiver solution that improves the data bandwidth and capacity of next-generation, multi-carrier wireless base stations compatible with 3G cellular transmission standards.
Analog Devices’ dual-channel AD8376 VGA (variable gain amplifier) and AD6655 IF diversity receiver solution replaces 48 discrete components, enabling 3G micro- and pico-cell base stations with dramatically reduced power consumption and physical volume. Each radio channel can handle up to six carriers. The new VGA and IF diversity receiver also increase automatic gain-control loop performance by 100 times existing options, which improves base station receiver sensitivity and dynamic range and ensures both weak and strong incoming cell phone call signals are quickly and effectively received and processed.
The AD8376 and AD6655 comprise the first two-chip dual-channel IF receiver optimized to handle both the main and diversity receive paths simultaneously. The combination of best-in-class performance, power consumption, size and cost is ideally suited to meet the wider bandwidth and multi-carrier signal processing demands of today’s wireless infrastructure equipment, while supporting emerging 3G and 2.5G mobile phone communications standards such as CDMA2000, UMTS and TD-SCDMA, as well as WiMAX.
The AD8376 is the first digitally-controlled VGA that enables 1dB gain-step resolution at the highest IFs. The device offers the industry’s best linearity of OIP3 50 dBm at 140 MHZ. This level of performance and step resolution simplifies receiver automatic gain control (AGC), and enables wideband multi-carrier radio platforms. A fine-step AGC loop allows the designer to maximize the ADC’s dynamic range, which is critical when handling either 3G or WiMAX multi-carrier wideband input signals.
The AD6655 integrates many of the functions required for diversity receive path in a single device, including an ultra-low-latency peak detector and an rms signal power monitor that can be used in conjunction with the AD8376 and logic to form a flexible AGC.
The AD8376 dual-channel digitally-controlled VGA is sampling now with full production scheduled for June 2007. The AD8376 is priced at $6.25 per unit in 1,000-piece quantities. A single-channel version, the AD8375, is sampling now with full production also scheduled for June 2007. The AD8375 is priced at $4.25 per unit in 1,000-piece quantities.
The AD6653/5 IF diversity receivers are sampling now with full production scheduled for June 2007. The 12-bit version, the AD6653, is priced at $57.97 and the 14-bit at $97.50, both in 1,000-piece quantities.