Targeting 3G handsets, a multimode UMTS/ GPRS/EDGE IC from Fujitsu Microelectronics needs no interstage transmit or receiver SAW filters nor separate low noise amplifiers (LNA) to achieve multiband operation. The result is a significant saving in BOM and PCB footprint, as well as layout constraints, as the transceiver's six outputs can drive the power amplifier directly. The MB86L01A supports GSM bands (GSM850, EGSM900, DCS1800, PCS1900), WCDMA (Bands I, II, III, IV, V, VI, VIII, IX, X, and XI) HSDPA category 10 and HSUPA category 6. [Note: the design team started with Motorola, then spun off as Freescale Semiconductor and is now a part of Fujitsu Microelectronics.]

According to Vivek Bhan, senior director, RF Engineering for Fujitsu Microelectronics America, the result was achieved by a combination of innovative architecture and intellectual property (IP), yielding an ultra-low-noise design. "One of the big challenges was making sure that the design and IP algorithm sufficiently filters out nearby interferers," he noted.

The receiver's seven inputs support WCDMA and GSM/EDGE, and it also incorporates anti-aliasing filters, digital channel filters, digital gain control and high dynamic range ADCs. Also included in the transceiver is a 3G DigRF interface to the baseband IC, with either SPI and/or GPOs to control the PAs, switching regulators, and antenna switch, along with simplified timing and control enabled by a microcontroller unit in the transceiver.

The design also reduces OEM product development time via an RF programming which also improves RF subsystem implementations with simplified Layer 1 programming and embedded intelligence. The engineer enters a single command defining the desired channel and power level; in turn, this command sets the parameters and times the events so that system compliance is virtually assured.

By: DocMemory
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