28 June 2011

Renesas announces high-output, low distortion GaN power amplifier module for 1GHz CATV 

Renesas Electronics Corp of Tokyo, Japan, which supplies semiconductors including microcontrollers, system-on-chip (SoC) solutions, and analog and power devices, has launched the MC-7802 gallium nitride (GaN) power amplifier module for applications such as trunk amplifiers in 1GHz cable television (CATV) systems.

CATV power amplifier modules are used mainly in the trunk amplifiers of CATV systems, the optical node units (ONUs) of hybrid fiber coaxial (HFC) systems, and the final stages of booster power amplifiers for common receiver units installed in multi-unit dwellings such as apartment buildings. The power amplifier modules amplify multiple channel signals to make up for transmission loss over the network. Since they amplify multiple channel signals, such as terrestrial digital TV, CATV, and Internet signals, better linearity (distortion performance) allows more stable data transfer, and better signal quality can be achieved. High output power provides greater flexibility in system design and makes it easier to keep costs down, allowing the network to be expanded by extending transmission distances and increasing the number of branches.

With the coming of digitization in recent years, CATV systems have gone beyond distribution of video content to offer hybrid services including, for example, Internet access and Internet telephony (VoIP), and the number of channels handled has proliferated, notes Renesas. In response, the use of systems employing the 1GHz band is expected to grow. However, although systems employing the 1GHz band can transmit more channels than existing systems (which use the 770–870MHz band, depending on the region), the increased number of channels brings issues such as increased output power and distortion. In addition, demand is rising for high-frequency semiconductor devices with high output power, low distortion, and energy efficiency for use in amplifiers in order to maximize the transmission distance and number of branches in order to reduce the transmission cost.

Renesas says that its new MC-7802 addresses this market demand by providing low power consumption with improved output linearity and distortion characteristics.

The MC-7802 incorporates newly developed GaN field-effect transistors (FETs) that can be operated at higher frequencies and deliver higher output power than existing Renesas Electronics power amplifier modules that use gallium arsenide. About double the output performance is achieved while maintaining current consumption and distortion performance at the same levels as existing products by optimizing the matching circuits of the GaN FETs and other components for CATV applications. This enables CATV transmission equipment makers to roughly double output power without increasing current consumption, so the coverage area of the CATV network overall can be expanded with no increase in power consumption, the firm says.

The new GaN FETs are fabricated not on the usual silicon carbide but on a less costly silicon substrate, which will simplify production by using large-diameter wafers in future, the firm adds.

Renesas says that it regards the GaN FET as a strategic product and plans to expand its power amplifier module product line-ups for CATV to form a family of products with a variety of gain performances. To aid growth of its share of the CATV power amplifier market, the firm plans aggressive sales promotion for Japan, North America, Europe and China.

Renesas also has plans to continue development work on products incorporating GaN FETs for high-frequency applications and to steadily expand its lineup of such products.

See related items:

Renesas Electronics strengthens compound semiconductor business

Tags: Renesas Electronics GaN FETs CATV

Visit: www.renesas.com