Multi-mode mobile phone RF integration is not a myth

JasonYoo

Multi-mode mobile phone RF integration is not a myth [Copy link]

Until now, established companies in the RF field have provided discrete RF solutions when designing multi-mode mobile phones. Although some people question whether an integrated solution is needed, Ashvattha Semiconductor believes that mobile phone manufacturers need integrated technologies that can reduce cost and space. As a new company, Ashvattha will start shipping a single-chip RF device for cellular phones later this year. The RF chip integrates multiple RF protocols such as GSM/GPRS, GPS and Bluetooth.

“The main reason is the psychological barrier, which is that they think it is impossible, so in addition to overcoming the technical barriers, you have to overcome the psychological barriers,” said Kartik Sridharan, CEO of Ashvattha, referring to the current discrete RF solutions in multimode mobile phones. “We have mastered this breakthrough technology, which allows us to integrate several wireless protocols on a single chip. At the same time, we have not forgotten those important parameters such as power consumption, size, synchronization and cost.”

The debate over RF integration

"They've done a really difficult job, so I take my hat off to them," said Jack Quinn, an analyst at Micrologic Research. "In addition to supporting cellular communications, future phones must support multiple wireless technologies, including Bluetooth and GPS. Ashvattha's technology could make phones lighter, cheaper and smaller if it makes it possible to integrate the RF portion of these protocols into a single chip."

Many governments require mobile phones to have GPS capabilities to ensure that emergency calls can be found, and in the coming year Bluetooth is expected to become the dominant method for wirelessly connecting handheld devices to other electronic devices, such as printers and PDAs.

Currently, most semiconductor manufacturers competing fiercely in the handheld device market have focused their attention on baseband integration. They are looking for ways to integrate Bluetooth baseband with GSM or CDMA baseband. Qualcomm has launched a baseband solution that integrates CDMA, GPS and Bluetooth. However, there has been no substantial action in RF integration.

Bridgette Bosentino, RFIF division manager at Motorola Semiconductor Products, explained that while demand for Bluetooth is increasing, she does not believe RF integration is the right move and, in fact, the potential cost will increase.

"In the next few years, there won't be many phones with Bluetooth, maybe 5 to 10%," Bosentino said. "Until these optional features become mandatory, there is obviously no business value in integrating the main transceiver with the optional features, at least at this stage."

However, Will Strauss, an analyst at Forward Concepts, said that when Bluetooth starts to take off, it will be widely used in mobile phones. And this integrated radio frequency device is exactly what the market needs.

Still, he said, “A lot of people are skeptical. Ashvattha is definitely breaking new ground, and if their predictions pan out, that will be exciting. The real question is: Can they do it cost-effectively?”

Sridharan revealed that the cost of three discrete RF devices in a mobile phone is about $60, while the integrated Ashvattha solution may only cost $30 to $40.

Ashvattha marches forward

Ashvattha was founded last January. Sridharan said the company has commissioned IBM to produce multimode RF devices using a 0.25 μm SiGe BiCMOS process, demonstrating the feasibility of Ashvattha's technology. He said devices with integrated GSM/GPRS, GPS and Bluetooth RF functions will begin mass production by the end of this year.

In addition, devices integrating CDMA, GPS and Bluetooth RF functions will also be available in the middle of next year. Depending on the progress of the 3G wireless market, Ashvattha plans to launch RF chips integrating W-CDMA, GPS and Bluetooth in late 2002 or early 2003. In addition, the company also plans to add RF functions of protocols such as 802.11a/b and HomeRF to the integrated devices.

Since crosstalk and noise currently hinder the intercommunication between RF transmitters/receivers of various protocols, different RF protocols have not been integrated together. By adopting the isolation structure and circuit structure design that Ashvattha has applied for patents, it is believed that interference can be fully reduced.

Ashvattha announced that it has received $4.5 million in funding from Comstellar Technologies and Redwood Investments. Comstellar is an investment company for high-tech companies. Ashvattha is now part of Comstellar's Components and Subsystems Group. Other companies in the group include DSP developer Kromos Technologies, RealChip, which develops SoCs for MoP applications, and laser diode manufacturer Axcel Photonics.