TOKYO, JAPAN: Renesas Electronics Corp. announced the development of the
MC-7802, a gallium nitride (GaN) power amplifier module for 1-gigahertz (GHz) CATV (cable television) systems. Designed for use as a power amplifier for applications such as trunk amplifiers for CATV systems, the MC-7802 achieves high output power and low distortion that are among the best in the industry today.
The MC-7802 incorporates newly developed gallium nitride field effect transistors
(GaN FETs) that can be operated at higher frequencies and deliver higher output power than existing Renesas Electronics power amplifier module products, which employ a different semiconductor material (gallium arsenide).
Approximately 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 manufacturers of CATV transmission equipment to roughly double output power without increasing current consumption, so the coverage area of the CATV network overall can be expanded with no rincrease in power consumption.
The newly developed GaN FETs are fabricated not on a substrate made of silicon
carbide, the material typically used previously, but on a silicon substrate. This will simplify production using large-diameter wafers moving forward.
Renesas Electronics regards the GaN FET as a key device and plans to expand its
power amplifier module product lineups for CATV to form a product family.
CATV power amplifier modules are mainly used 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 multiunit dwellings such as apartment buildings. These power amplifier modules are semiconductor devices that 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) secure 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. In response, the use of systems employing the 1 GHz band is expected to grow.
However, although systems employing the 1 GHz band can transmit more channels than existing systems (which use the 770 MHz or 870 MHz 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.
The MC-7802 addresses this market demand by providing low power consumption with improved output linearity and distortion characteristics.