Microwave Engineering Europe - January/February 2009 - (Page 27)

PRODUCTS 27 120 W GaN HEMT transistors target W-CDMA, LTE and WiMAX applications Low frequency TCXOs target low jitter clocking for mobile RF applications Greenray Industries has announced the availability of the T124 series TCXO, an ultra-low frequency oscillator that is available down to 650 Hz in a low profile, compact SMT package. T124 series TCXOs cover 650 Hz to 1.25 MHz and provide stable, low frequency squarewave output (temperature stability to ±0.3 ppm over -40 to +85 degrees Celsius). The TCXO accepts a 3.3 V input voltage and offers optional EFC (Electrical Frequency Control) to adjust for long-term aging. T124 TCXOs Cree has released two 120W, highly efﬁcient GaN HEMT microwave transistors in sample quantities for telecommunication applications such as W-CDMA, LTE and WiMAX. Due to the unique combination of high RF power density, low capacitance and high thermal conductivity silicon carbide (SiC) substrates, these transistors provide superior performance compared to other technologies such as GaAs MESFET or Si LDMOSFET. Two demonstration ampliﬁers — one for each device — are available for transistor evaluation. The transistors consist of single, input-pre-matched GaN HEMT devices providing over 120 W of saturated power in small, industrystandard ceramic-metal packages. These transistors provide convenient values of input and output impedances to allow device matching over greater than 30 percent instantaneous bandwidths. The CGH21120F is designed to be used primarily in the 1800 to 2300 MHz range, while the CGH25120F is optimized for the 2300 - 2700 MHz range. This allows the two transistors to be used for DCS (GSM), PCS (GSM and CDMA), WCDMA, and LTE. As an example, the CGH21120F provides more than 110 W of peak CW power at 70 percent efﬁciency with a gain of 16 dB when operated at 28 V. Under W-CDMA 3GPP stimulus, the transistor provides 25 W average power with 40 percent efﬁciency in Class A/B operation. According to the company, this is the highest known W-CDMA efﬁciency from any commercially available transistor at this power level. “High efﬁciency is becoming a driving factor, along with increased emphasis on higher average powers, for multichannel/carrier applications,” said Jim Milligan, Cree director of RF and microwave products. According to the company, these transistors also allow a high degree of digital predistortion correction so that ACLRs (Adjacent Channel Level Ratios) of -60 dBc can be routinely achieved. In a recent demonstration, two CGH21120F transistors, in a Doherty ampliﬁer conﬁguration, generated 80 W of average power under W-CDMA with a record efﬁciency of 52 percent. The CGH21120F and CGH25120F complement the range of the company’s RoHScompliant HEMT microwave transistors for WiMAX applications available for 802.11x OFDM average power levels of 2 W, 4 W and 8 W. www.mwee.com/213000007 feature a rugged, AT strip crystal to provide superior aging characteristics to 3 ppm over 15 years. With compact size and low power consumption, the TCXO series is ideally suited to low jitter clocking for mobile RF applications. www.mwee.com/212900038 High reliability microwave switch drivers deliver switching speeds of under 10 ns Microsemi Corporation has launched a series of PIN diode microwave switch drivers that boast state-of-the-art switching speeds of less than 10 ns, designed for defense and other high reliability applications. Designated the MSD7800 series, these microwave switch drivers are designed for both SPST and SP2T switches, include internal spiking and decoupling capacitors, and are compatible with standard logic protocols. Additional conﬁgurations are available upon request. This PIN diode microwave switch driver series is assembled on FR4 circuit boards using conformal coated components which meet RoHS lead-free standards, with full MIL-883 screening available. Advanced cost-efﬁcient design techniques allow MSD7800 series drivers to be priced competitively. www.mwee.com/212701040 TR3M narrowband transceiver serves low power multi-channel applications The TR3M from Radiometrix is a high-end multi-channel narrowband transceiver that operates in the European 868 MHz band, with custom variants for any 3 MHz frequency block from 860 to 870 MHz available on request. The transceiver supports data rates of up to 5 kbits/s, and has a usable range of over 500 m. Employing a 1200 baud dumb modem it allows transmission across 80 different channels. Consumption is 85 mA for the transmitter and 30 mA for the receiver, while the receiver sensitivity is -118 dBm (for 12 dB SINAD). The module measures 59- x 38- x 10-mm. It conforms fully to EN 300 220-3 and EN 301 489-3. www.mwee.com/212501091 ● Microwave Engineering Europe ● January/February 2009 www.mwee.com http://www.mwee.com/212900038 http://www.mwee.com/212701040 http://www.mwee.com/213000007 http://www.mwee.com/212501091 http://www.mwee.com

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Microwave Engineering Europe - January 2009 News Contents Comment Using KPIs to Ensure Quality in a Converging Network Amplifier Error Vector Magnitude Characterisation Using High-Speed Modular PXI Instruments GPS: Making a Play for Femtocells Accelerating Global WiMAX Adoption: The Move to Picocell and Femtocell Base Stations Addressing PA Efficiency for Multi-Mode Wideband Handset Applications Wi-Fi: Mobile Feature or Fundamental RAN? Products Calendar

Microwave Engineering Europe - January/February 2009

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