A wireless communication system's performance is directly impacted by noise and the signal-tonoise ratio (SNR). As distance increases and the RF signal grows weaker, the SNR may become too small to allow effective communications. Compared to the solutions that are currently implemented in IEEE 802.11x wireless-localarea- networking (WLAN), Bluetooth, and ZigBee systems, RFaxis has developed a technology that promises to significantly improve the system noise figure. It details devices based on this technology in a white paper titled, "RFaxis System Noise Figure Enhancements."
The 14-page white paper begins by discussing the design and implementation of conventional wireless communications systems using front-end modules, which include discrete switches and filters. The paper asserts that such conventional circuits adversely impact system noise figures because of the insertion loss of the switch, which is usually 0.5 dB or more. The system noise figure is further raised by the insertion loss of the bandpass filter. In contrast, RFaxis has produced the RF front-end integrated circuits (RFeICs). When implemented in a circuit design, they promise to improve the system noise figure while delivering increased power efficiency, bandwidth, and a greater transmission range.
Test results and examples are provided for Bluetooth, WLAN, and ZigBee test cases. The examples illustrate that even a modest low-noiseamplifier (LNA) noise figure with a small amount of gain inserted into the receiver chain can substantially improve the system noise figure.
RFaxis, Inc., 36 Discovery, suite 120, Irvine, CA 92618; (949) 336-1360, FAX: (949) 336-1361, internet: www.rfaxis.com.
