Microwave Engineering Europe - December 2007 - (Page 34) 34 PRODUCTS Reference design for MicroTCA WiMAX transceiver platform Lime Microsystems, a fabless semiconductor company specializing in digitally configurable transceivers for the next generation of wireless broadband systems, claims to have launched the world’s first reference design for a MicroTCA broadband wireless transceiver. Targeted at small cell WiMAX base station applications — femtocells and picocells — the transceiver has 6 user-selectable channel bandwidths from 1.5 MHz to 14 MHz and can be digitally configured to operate in bands from 2 to 4 GHz. The re-configurable design supports a variety of network configurations, bandwidths and data rates. This minimizes costs and inventory for wireless system OEMs and operators. Using a high level command set, the design can be configured for half-duplex and full-duplex operation in both frequency division multiplex (FDM) and time division multiplex (TDM) modes. The board can also be used as a ‘plug-andplay’ transceiver for rapid evaluation and deployment of WiMAX base stations based upon ACTA or MicroTCA standards. The zero-IF transceiver uses 12-bit baseband ADCs and DACs. A 40 MHz sampling rate is derived from a lownoise clock. Its serial RapidIO interface supports a throughput of up to 3.125 Gbps and can communicate via any advanced mezzanine cards (AMC) ports. A single port carries both I/Q and control traffic and an I/Q record and playback capability simplifies testing. A full speed USB interface is provided for PC controlled standalone operation. By covering a wide as possible range of interest in terms of bandwidth enables customers to reduce inventory, cut costs and rapidly configure a system to changing conditions. The reference design currently spans 2 to 4 GHz bands, but the company is looking ahead — for example 700 MHz to 4 GHz and beyond. The reference design is based on a mature second generation SiGe process that is both proven and portable. It can also be ported seamlessly to CMOS. Some key features of the design include the use of a zero-IF architecture with automated calibration and FPGA-based DSP re-sampling. This not only makes the design adaptable for various sampling rates, but provides designers with a host of FPGA resources to evaluate, diagnose, test and tweak the transceiver. Lime has been working closely with a number of leading companies in both baseband and RF amplifier technologies. Formal partnership announcements will follow in the next few months, and these agreements will enable Lime to support its customers in the development of complete base stations in which interoperability between the main circuit functions is guaranteed. Lime is backed by ACT Venture Capital and DFJ Esprit and was founded in March 2005. The company boasts a world class RF design team in the UK that develops IP, backed by a team in Lithuania that implements the IP. A key on-going goal of the company is to develop ‘onechip’ configurable wide-band transceiver solutions while alleviating price pressure dictated by the market. www.mwee.com/204201878 Multipurpose 5.0 to 9.0 GHz low-noise amplifier communications, military and space radar applications Tyco Electronics has introduced the M/A-COM MAAM-007095-A3GVSA low noise amplifier, a two-stage variable gain amplifier that is ideal for military and space radar, tactical communications systems and commercial pointto-point radio applications. Featuring a variable gain control of 0 to 5 V and 25 to 38 dB gain, the amplifier can be used as a LNA (Low Noise Amplifier), intermediate amplifier or driver stage amplifier. Typical noise figure is 2 dB with a 1 dB compression point of 17 dB. The amplifier utilizes a 12 to 15 V power supply, and can be mounted in either a connectorized or drop-in configuration. The device resides in a hermetically sealed housing and can accommodate either field-replaceable SMA or GPO connectors. It is matched to 50 ohms on both input and output, and is fabricated using high-performance, highreliability military standard processes. www.mwee.com/204201802 High-frequency crystal oscillators provide low-jitter performance DS4-XO series of crystal oscillators from Maxim Integrated Products support frequency operation from 75 MHz to 622.08 MHz. The miniature crystal oscillators are available in a small, 5 mm x 3.2 mm package and provide jitter performance of less than 1psRMS (12 kHz to 20 MHz) over the -40 degrees Celsius to +85 degrees Celsius extended temperature range. Manufactured using fundamental AT-cut crystal technology with no overtone, the DS4-XO series integrates a low-noise PLL-based oscillator designed in the company’s own SiGe process. Fifty-five percent smaller than competitive solutions, the oscillators are ideal for space-constrained designs used in Fibre Channel, Ethernet, 10G Ethernet, SONET/SDH, InfiniBand®, GPON, BPON, PCI Express®, and SAS/SATA applications. The devices’s miniature package incorporates thermally managed design techniques specifically targeted for highcurrent (65 mA to 75 mA, typical), high-frequency (100 MHz and greater), differentialoutput (LVDS, LVPECL, HCSL) applications. LVDS and LVPECL output options are available for all frequencies except the 100 MHz version. This frequency is generally used in PCI Express applications and is provided with (differential) HCSL output type. These crystal oscillators are highly competitive against SAW-based oscillator designs, which are manufactured in a larger, 5 mm x 7 mm ceramic package. Offering comparable phase-jitter performance (under 1psRMS), the DS4-XO devices deliver a much higher degree of frequency stability (±40 ppm versus ±100 ppm or greater) over the extended temperature range. Additionally, the series provides extremely low, ±7 ppm aging over 10 years, whereas SAW-based oscillators typically provide ±1 ppm aging per year. www.mwee.com/204201699 Microwave Engineering Europe ● December 2007 ● www.mwee.com 034_MWEE.indd 34 23/11/07 13:52:33 http://www.mwee.com/204201802 http://www.mwee.com/204201699 http://www.mwee.com/204201878 http://www.mwee.com
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