At the Hawaiian Convention Center in Honolulu this week, RF power transistor vendors from the West and the East convened at the IEEE’s MTT-S International Microwave Symposium to showcase their latest developments in LDMOS, gallium arsenide (GaAs) and gallium nitride (GaN) transistors. While Freescale Semiconductor unveiled seven new LDMOS RF power transistors to enable WCDMA and CDMA2000 base station transmitters to exploit the full potential of Doherty amplifier architecture, NXP Semiconductor displayed its Gen6 LDMOS portfolio for mobile WiMAX and other wireless applications. TriQuint Semiconductor announced two 0.15µm GaAs pHEMT-based satellite communications (Satcom) high-power amplifiers (HPAs) that boasted improved performance with overall size reduction. Nitronex, Cree, Eudyna and Toshiba demonstrated new capabilities in GaN power transistors.

Speaking of LDMOS, Freescale’s new devices are tailored for signals with high peak-to-average (PAR) ratios. Covering cellular, PCS and WCDMA frequencies, two of the devices (MRFE6S9205H/HS and MRFE6S9135H/HS) operate in 865 MHz – 960 MHz band, two other (MRF6S19200H/HS and MRF6S19140HR3/HSR3) in the 1930 MHz – 1990 MHz band, and three (MRF7S21170HR3/HSR3, MRF6S21190HR6 and MRF6S21140HR3/HSR3) in the 2110 MHz – 2170 MHz. In addition, the supplier also released a 1 kW pulsed RF output LDMOS at 130 MHz with highest drain efficiency and power. Operating at 50 V, the MRF6VP11KH provides designers of high-power systems such as magnetic resonance imaging (MRI) systems, CO₂ lasers, plasma generators and other systems with significant benefits when compared to bipolar and MOSFET devices, stated Freescale..

On the GaN front, Nitronex disclosed a 4 W GaN-on-Si pre-driver power transistor designated NPTB00004. At 900 MHz, the NPTB00004 power transistor has input/output impedances near 50 ohms, reducing the need for external matching circuits. Under WCDMA modulation at 2.1 GHz, the power transistor typically delivers 14.5 dB of power gain, 25% efficiency at an ACPR of -45dBc.

“The NPTB00004 provides improved power and efficiency for a given linearity compared to existing solutions in the pre-driver market,” said Chris Rauh, Nitronex vice president of sales and marketing. “We believe the combination of our SIGANTIC process and the qualified low-cost plastic overmold packaging assembly at Amkor Technology, Inc. is a winning combination for designers.” It is sampling now with full production qualification expected in August.

Likewise, Cree announced sample availability of three new GaN HEMT devices especially designed for WiMAX applications. These include CGH27120, CGH27060 and CGH27030, offering linear power up to 16 W under OFDM modulation in small-footprint packages.

While Japan’s Eudyna Devices displayed an 800 W AlGaN/GaN HEMT, operating at 65 V drain bias voltage for S-band high power application, Toshiba America Electronic Components Inc. (TEAC) revealed its first commercially available X band GaN HEMT for radar systems and medical applications. Designed for 8.5 GHz – 9.6 GHz with output power of 50 W, the TG18596-50 is an internally matched GaN HEMT that features 3 dB compression point of 47.5 dBm (typical), linear gain of 9.0 dB (typical), and drain current of 4.5 A (typical). “As a follow-on to this initial device, Toshiba is also developing C and Ku band GaN HEMTs for satellite communications applications,” said Homayoun Ghani, business development manager for TAEC’s microwave, logic and small signal devices.

Microwave and millimeter-wave packaging supplier StratEdge has readied a line of high-performance semiconductor packages that operate from DC to 50 GHz in hermetic versions. According to StratEdge, to make a hermetic version of its ceramic products, it developed a new technology that uses glass lamination and metallization. Packages that are available in hermetic versions include StratEdge’s low-cost ceramic (LLC), SMX surface-mount package, and SE50 series package. All packages are lead-free, meet RoHS and WEEE compliance, and are manufactured in the company’s ISO 9001:2000 facility in San Diego, Calif.

While the LCC family of packages is designed specifically for VSAT applications with performance from DC to 23 GHz, the SMX series ceramic packages provide good electrical transition performance for die in the DC to 18 GHz range. The SE50 line of packages offers standard off-the-shelf package designs working between DC and 50 GHz. They meet the stringent requirements for point-to-point and point-to-multipoint applications, said StratEdge. With their standard copper composite base and patented microstrip-imbedded microstrip-microstrip transition design, the SE50 packages provide high electrical performance in a thermally stressful environment, according to the manufacturer.

Combining polar modulation techniques with its proprietary FullSpectra architecture and 0.18 micron silicon germanium (SiGe) BiCMOS process, fabless semiconductor supplier Sequoia Communications has readied a multimode transceiver chip that claims highest level of integration, lowest power consumption and the lightest phone level calibration burden. These advancements improve the battery life and reduce the footprint and the overall manufacturing costs of 3G handsets, stated Duncan Pilgrim, Sequoia’s director of product marketing. According to Pilgrim, the SEQ7400 is the industry’s first single-chip, polar transmit, seven-band, HEDGE (HSDPA/WCDMA and EDGE/GPRS/GSM) RF transceiver based on its patented FullSpectra architecture.

According to Brian Modoff, senior analyst and managing director at Deutsche Bank Securities, battery life, size and cost are primary obstacles to mass adoption of 3G technologies by consumers. “We estimate that the 3G handset market will reach 680 million WCDMA units in 2010, with HSPA accounting for 310 million of those units, and improvements in battery life, form factor and cost are critical to enabling this growth,” asserted Modoff.

As per Sequoia, polar modulation, the de facto standard transmit architecture in GSM/EDGE mobile devices, was successfully implemented for WCDMA in its first product, the SEQ5400. With the SEQ7400, the company is demonstrating working polar modulation in WCDMA/HSDPA. As a result, the company has established a clear path to large signal PA modulation in future products. Moreover, this architecture will enable a cost- and power-efficient means to integrate higher bandwidth standards, such as UTAN LTE, WiMAX and WiBro, in subsequent products, noted Pilgrim.

The product supports WCDMA, HSDPA, EDGE, GPRS, GSM modes across seven frequency bands simultaneously, making it applicable to major networks worldwide. The integrated receiver includes all LNAs and, unique to the SEQ7400, also eliminates the need for external WCDMA SAW filters. In addition, the low noise polar modulation transmit architecture eliminates the transmit SAW filters for GSM/EDGE, said the developer.

The integration of LNAs and filters significantly reduces the RF bill of materials (BOM) and board layout complexity creating a new benchmark in size and cost for all mobile devices using this product, said the manufacturer. “Lowering the overall cost of ownership and reducing the size of mobile handsets is critical for the broad adoption of 3G technologies,” said David Shepard, CEO of Sequoia Communications.

Complex calibrations and cumbersome programming interfaces have long plagued the RF transceiver market, making these devices difficult to integrate into a phone. Polar architectures have traditionally suffered from issues with calibrations. To address this, Sequoia Communications designed significant intelligence into the SEQ7400, making it a virtually self-calibrating device with a very simple programming interface. There is no burden placed on the baseband device or at the phone level. This will significantly reduce the factory calibration time for handset manufacturers, leading to much lower manufacturing cost and higher throughput.

The SEQ7400 comes in an 8 mm x 8 mm BGA package. Samples and complete RF evaluation boards are available now. Volume production is slated for the second half of the year. A 7 mm x 7 mm flip-chip version is also in the works and is expected to be released in summer. Pricing in volume is >$5.00. Meanwhile, efforts are underway to migrate to 90 nm RFCMOS using proven architectures.

LeCroy has introduced its SDA 18000 oscilloscope, in what they say is the industry's highest bandwidth 18 GHz -- the highest sampling rate -- 60 GS/s -- and longest memory -- up to 150 million points.

Texas Instruments has introduced a tiny, high-performance power conversion IC to work in tandem with processing platforms that use TI's SmartReflex power and performance management technologies