3. RF Engineering

A lot of people regard RF engineering as a black science. Unlike digital design, which has shades of gray, there is always a level of uncertainty that lies with designing RF products. Led by Dr. Y.Y. Tsai, one of the most respected RF experts in Taiwan, DNI's RF engineering team seeks to design products that not only meet IEEE standards, but exceed it with enhancements that bring about a new level of performance.

3.1 Design Experience

Solid design at the circuit level involves a deep understanding of component characteristics. It is with this knowledge that a designer may then gain an in-depth grasp of what is involved and proceed to optimize a design.

Below is a list of RF components that DNI has worked with in the past two years alone.

In addition, DNI possesses the ability to design an antenna to better optimize the design. Below is a list of the types of antennas DNI employs to further enhance performance of its wireless products.

With each type of antenna, DNI's talented RF engineers are able to further modify the basic design and come up with new ways to suit the purpose of each individual product. Case in point, the following slide illustrates the beam-forming antenna our engineers use to enhance 802.11g performance.

Beam Forming Antenna

In this example, multiple dipole antennas are put together with the phase shifters behind them. DNI engineers are able to focus the energy of the radiation to a specific direction depending on the phase shift of the signal.

Given DNI's strength in RF engineering, it's no wonder that DNI is now among the leaders of WiFi shipments in Taiwan.

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3.2 WiMAX

DNI was one of the first ODMs in Taiwan to venture into the 802.16-2004 space. Working in the 3.5GHz band is somewhat different from the 2.4GHz and 5GHz band that we are accustomed to in the past, so novel approaches were invented to enhance the performance while optimizing cost.

Currently shipping is an indoor product.

WiMAX 802.16d Indoor CPE

Indoor CPE's biggest appeal is that it doesn't require a truck-roll for installation. However, unlike wired broadband such as cable or DSL, WiMAX's wireless nature poses some confusion for the end-customer, as the user may or may not know how to place the CPE in the optimal position.

To address this issue, our engineers placed three antennas inside the device: one out in front, two on each side. The user may place the CPE at their will, and the one antenna among the three that picks up the strongest signal will be the one transmitting and receiving. If further placement optimization is needed, there is a signal indicator on the front panel denoting the signal strength, so that the user may move the CPE until he/she gets the strongest signal. This configuration gives a gain of 8.5dBi.

If 8.5dBi isn't sufficient to satisfy the carrier, DNI also designed directional antenna with a gain of 14dBi.

WiMAX Indoor Antenna (3.4-3.6GHz)

Low cost, yet effective, this design has earned the recognition of tier-1 OEMs as a solution that is well-suited for some difficult to reach areas.

Outdoor products are also in demand, so DNI is now currently sampling an outdoor CPE that is industrial grade and weather-proof.

This design boasts antenna gain of 14.5dBi, and the enclosure is IP67 compliant. With outdoors placement and high antenna gain, this product is ideally suited for carriers looking for maximum range.

With a complete portfolio of 802.16-2004 products, DNI now looks to add 802.16e products into its line. As WiMAX becomes ever more popular, DNI will be in a good position to take advantage of the favorable market conditions.

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