Power transistor touts 'highest' performance level

Renesas Technology Corp. has announced the RQG2003 high-performance power SiGe HBT, the successor of the company's current HSG2002. Touting the industry's highest performance level, this power transistor is for use in products operating in the 5GHz and 2.4GHz bands, such as WLAN terminals, digital cordless phones and RF tag readers/writers.

At 5GHz, the power transistor delivers a power gain of 6.4dB, 1dB gain compression power of 26.5dBm, and power addition efficiency of 33.6 percent. At 2.4GHz, the device delivers a power gain of 13dB, 1dB gain compression power of 26.5dBm, and power addition efficiency of 66 percent. This performance enables low power consumption in 802.11a-compatible WLAN devices, digital cordless phones and other devices operating in the 5GHz band, as well as in 802.11b/g-compatible WLAN devices, RF tag readers/writers, and other devices using the 2.4GHz band.

Unique structure
The RQG2003 is the first Renesas product to use the company's unique double-trench structure in which trench isolation and conductive trench are formed in a single transistor area. Insulating the transistor from the silicon substrate with trench isolation reduces parasitic capacitance (between the substrate and transistor) that causes degradation of high-frequency characteristics. In addition, the conductive trench is constructed so as to connect the electrodes and substrate by means of via holes, making it possible to reduce inductance due to wire bonding. Use of this double-trench structure has resulted in major improvements in power gain and power addition efficiency in the 2.4GHz and 5GHz bands.

A SiGeC process is used in which a SiGe base is doped with carbon, and optimization of the transistor pattern has also been carried out. This has resulted in major improvements, with collector current density increase, and 1dB gain compression power improvement by approximately 1.5dBm compared with the HSG2002.

Totally Pb-free
The RQG2003 is packaged in a surface-mount 8-pin WQFN0202 (Renesas package code) with dimensions of 2-by-2-by-0.8mm. The device uses an optimal silver paste for die bonding, and Sn-Bi is used for package electrode plating, providing a totally Pb-free implementation.

Sample shipments of the RQG2003 will begin this month in Japan.