- Buyers Guide
5G and IoT Supplement
RFaxis, a fabless semiconductor company focusing on innovative, next-generation solutions for the wireless and connectivity markets, unveiled its RFX8000 ultra-high efficiency multi-mode/multi-band transmitter integrated circuit (IC) chip for 3G and 4G cellular wireless devices. This RFX8000 chip is based on a new patent pending RF multi-mode/multi-band transmit IC architecture innovated by RFaxis for creating single-chip/single-die solutions specifically designed to deliver longer talk-time, clearer calls and higher data rates for cellular mobile phones.
The new RFX8000 chip comes fully integrated with linear WCDMA/EDGE power amplifiers, switching functionality to support multiple modes/bands and on-die matching circuitry. The RFX8000 chip will initially be designed and manufactured using standard 0.18 micron CMOS silicon processes.
"While our current RF Front-end Integrated Circuit (RFeIC) chips for Bluetooth, WLAN and dual-mode Bluetooth/WLAN all deliver value to cell phone manufacturers today," explained Mike Neshat, President and CEO of RFaxis, "our RFX8000 transmitter IC chip addresses the most critical challenge impacting the performance of 3G and 4G multi-mode/multi-band cell phones: transmit power efficiency and performance. In fact, the RFX8000 can enable a dramatic 200 percent to 400 percent improvement in the average (operational) power efficiency for such cell phones. This is revolutionary considering that cell phone power amplifier vendors cannot achieve average power efficiencies above 15 percent. Moreover, the RFX8000 is far more than just a power amplifier; it is a complete transmit IC device with all of the on-die amplify, switching and matching functionality needed for multi-mode/multi-band cell phone OEM/ODMs to rapidly design ultra-high efficiency mobile phones. In addition to enabling longer talk time, our disruptive RF multi-mode/multi-band transmit IC architecture and circuit designs enable high quality connections and mitigate excessive roaming, thereby conserving the mobile phone battery power and extending the time between battery recharges. This means tremendous value, especially considering the massive and booming global cell phone market."
Oleksandr Gorbachov, RFaxis' CTO, explains further, "Today, multi-mode mobile phones operating in EDGE mode require linear transmit behavior to maximize power efficiency. Unfortunately, the conventional multi-mode cell phones' transmit GSM/EDGE chain utilizes GSM power amplifiers, which are typically non-linear and therefore result in wasted power when in EDGE mode. Also, cell phone size and cost constraints force designers to use the same GSM power amplifier for GSM, EDGE and WCDMA modes, resulting in trade-offs needed to achieve linear and non-linear operations in the same device, and thereby causing adverse power efficiency degradation. A GSM power amplifier typically has an efficiency of around 50 percent when in GSM mode, but drops below 25 percent in EDGE mode, and these efficiencies are relative to the maximum rated output power. A more meaningful metric for real cell phone operation is average power efficiency. Unfortunately, the average power efficiency for GSM power amplifiers drops well below 15 percent for both GSM and EDGE modes, primarily due to inefficiencies in controlling power levels relative to one's constantly changing distance from a base station. Furthermore, today's multi-mode mobile phones include independent WCDMA (or CDMA2k) chains that contain their own power amplifiers, thereby forcing more tradeoffs and power usage inefficiencies. Our new RF multi-mode/multi-band transmit IC architecture embodies a holistic approach to the cell phone transmit function, and optimizes transmit power usage not only across the various 3G/4G modes, but also across key operating bands."
Get access to premium content and e-newsletters by registering on the web site. You can also subscribe to Microwave Journal magazine.