January 2009


Leadership through technology competence

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Intensive research and development work is the foundation of innovation. Today EPCOS generates over 40 percent of its sales with electronic components, modules and systems that are less than three years old. The company’s innovativeness is built on its competence in technology, materials and production processes.

Miniaturization remains one of the strongest motors of innovation in electronics. In particular, the telecommunications industry is demanding ever smaller component solutions. In addition to telephony, mobile phones offer more and more additional functions such as camera, navigation and TV. Such a high degree of integration while retaining the same compact size of the handset can only be achieved by continually reducing the size of the components.

In the year 2010 over 40 percent of all mobile phones sold will be UMTS-capable according to market researchers. Because these handsets must also continue to operate in existing GSM networks and support other wireless standards and services such as WLAN, GPS and Bluetooth, the number of filters per phone is rising. Four frequency bands alone are used in the existing GSM networks around the world. For UMTS, ten bands have been established with six more in the planning. In order for UMTS-capable phones to function globally they require a combination of filters designed specifically for the frequency bands and standards. Already, such mobile phones need an average of up to five RF filters for the respective frequencies.

World market leader in RF filter technology

As the world’s leading manufacturer of SAW components, EPCOS is continuously building on this expertise by developing new technologies for multiband and multimode mobile phones. For example, the R&D engineers have combined SAW filters with BAW (bulk acoustic wave) filters to create the world’s hybrid BAW-SAW duplexers for operation both GSM and WCDMA bands (Fig. 1). "In contrast to its competitors in the semiconductor industry, EPCOS can integrate both SAW and BAW functions together, thus offering customers the benefits of both technologies in a single component,” points out Dr. Werner Faber, Chief Operations Officer and Member of the Management Board of EPCOS. Thanks to BAW technology, the high power compatibility and low insertion loss of microwave ceramic filters and the miniaturization potential of SAW filters can be combined in a single product.


The latest duplexers from EPCOS for WCDMA feature a footprint of just 2.5 x 2.0 mm² and an ultra-flat insertion height of 0.5 mm.

In addition to filters, EPCOS also develops complete front-end solutions. One example is the world’s most compact all-in-one front-end module for Bluetooth and WLAN applications to the 802.11 b/g/n standard. With an insertion height of 1.4 mm, it has a footprint of only 4.5 x 3.2 mm² on the circuit board. The LTCC module integrates a WLAN power amplifier, a WLAN-Bluetooth switch, a receive balun, and a bias circuit with ESD protection. In addition, the coexistence filter allows simultaneous operation of WLAN and Bluetooth applications with all mobile phone standards. The D6101 module thus provides all the required functions between WLAN or Bluetooth RF transceivers and the antenna. “With these solutions we are not only continuing to drive miniaturization forward,” explains Christian Block, Vice President and Chief Technology Officer of the SAW Division, “we are also simplifying our customers’ design work.”

RF-MEMS technology improves signal quality and cuts power consumption

Miniaturization, however, doesn’t stop with the filters and modules. In order to enable signal processing in the smallest space possible, EPCOS has turned its attention to the promising field of RF-MEMS. R&D engineers are now working on developing tunable microcapacitors to optimize the impedance of the antennas of multiband mobile phones under varying operating conditions. These MEMS-based tunable RF networks help to improve the transmission quality of mobile phones. Moroever, they will also make it possible to cut the power consumption by up to 25 percent. “With RF-MEMS we are strengthening our core competence in RF technology and opening a new and promising area of applications in mobile phones,” says Christian Block.


Piezoelectric materials with high innovation potential

EPCOS is firmly established as the world market leader for piezo actuators for automotive fuel injection systems. In order to further advance the piezo actuators, EPCOS engineers are developing high-performance materials to enable higher force and/or displacement (Fig. 2). “We will be able to make our actuators perform even faster and with greater precision,” promises COO Dr. Werner Faber. “This will enable motors with even lower fuel consumption and carbon dioxide emissions.” A further benefit of the new generation of actuators is the fact that the electrodes are no longer made of palladium by rather of copper, which is much less expensive.

The new generation of piezo actuators helps to reduce fuel consumption and carbon dioxide emissions.

The portfolio of piezo products is being continuously expanded: “The piezoelectric effect provides great innovation potential,” says Faber. “We now offer miniature components such as transformers, benders and resonators,” says Faber. Contrary to conventional electromagnetic transformers, piezo transformers can transform voltages mechanically, achieving power densities of up to 50 W/cm³ and translation ratios of over 1 to 1000. With their high power density and efficiency in a miniature size, they can be easily integrated into compact solutions (e.g. ultra-flat transformers) for applications such as Xenon flash modules in cameras or power supplies for LED lamps. What’s more, they cause no EMI.

New piezo products

Piezo benders, for example, can be used not only for the actuation of valves, but also for energy harvesting in the tire pressure monitoring systems (TPMS) of cars. With the new miniaturized piezo resonators linear motors can be driven with a supply voltage of less than 3 V. “Our know-how is the enabler for the world’s smallest linear motor,” points out Dr. Justinus Slakhorst, Chief Technology Officer of the company’s Ceramic Components Division. The latest generation of the motor measures a tiny 1.82 x 1.82 x 6 mm and is optimized for phone camera modules with optical zoom functionality.

A further strength of the company with regard to material and technology competence lies in the utilization of the piezoresistive effect. Based on this EPCOS engineers are also developing advanced piezoresistive pressure sensors based on silicon chips. Thanks to new packaging technologies these components can deliver highly accurate differential pressure measurements in harsh environments such as in hot exhaust gas or fuel vapors. These components help to noticeably improve the performance and energy efficiency of combustion engines.

PTC heating elements can now be manufactured using innovative injection molding technologies, enabling the production of the ceramic components in a virtually unlimited variety of shapes.

Innovative production processes enable new heating elements

Production technologies also play an important role in EPCOS’ R&D efforts, for example, for products such as PTC thermistors which are seemingly technologically mature. PTC thermistors, a product area in which EPCOS is world market leader, are self-regulating heating elements based on the ceramic material barium titanate, which in the past could only be processed by pressing, cutting or stamping. Now a new production technology developed by EPCOS allows injection-molded thermistors to be designed in an endless variety of custom shapes such as tubes, nozzles or the rotary blades of ventilators, thus opening up many new applications for ceramic heating elements (Fig. 3). “Because they can be incorporated precisely where the heat is required, they can also avoid heat transfer losses and save energy,” explains Dr. Christian Hoffmann, head of Materials Research at EPCOS’ competence center for ceramic components in Deutschlandsberg, Austria. “These customized thermistors are thus suitable for applications such as pre-heating alternative fuels in motor vehicles and for use in electrical consumer devices such as coffee makers or hair dryers.”

The intensive R&D activities are an important strategic factor for EPCOS in order to differentiate the company from the competition through ongoing innovation success. “Innovation enables us to give our customers competitive advantages through technologically superior products,” summarizes COO Dr. Werner Faber.



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