Modular RF for Embedded System
Explore the advancements in Modular RF technology tailored for embedded systems. This presentation by Ying-zong Huang, dated November 25, 2002, discusses the essential features of modular RF solutions, including portability, self-containment, and real-time remote operation through wireless data transfer. Covering applications in cordless phones, baby monitors, and Bluetooth/802.11-enabled devices, it highlights Linx Technologies' innovative RF modules. Learn about transmitter and receiver specifications, antenna considerations, and the importance of efficient power management and compliance with FCC regulations.
Modular RF for Embedded System
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Presentation Transcript
Modular RF for Embedded System EE 281 November 25, 2002 Ying-zong Huang
Special Embedded Needs • Portable • Self-contained • Small • Real-time remote operation Wireless data transfer (also portable power…)
Modular RF • Faster TTM for systems with a radio component • Cordless telephone • Baby monitors • OEM’s • Bluetooth-enabled • 802.11-enabled
Modular RF • No (or very very few) external components • Linx Technologies: • http://www.linxtechnologies.com • Module + Antenna = Wireless • RF modules (miniboards) • LC Series (SAW, 315, 418, 433 MHz) • KH Series (with Encoder/Decoder) • HP-2 Series (FM/FSK, Multi-channel, 900 MHz)
Linx LC Series - Transmitter • 2.7V–5.2 VDC • Direct Serial Interface • (Digital) data rates up to 5 Kbps • Up to 300 feet
Linx LC Series - Receiver • Similar features as Transmitter
Linx LC Series - Modulation • Carrier Present/Carrier Absent modulation • Saves power when sending ‘0’ • Takes advantage of FCC rules • Easy to understand • Encoding not provided by LC Series: Add your own protocol (By way of Pascal Stang: http://www.procyonengineering.com/hardware/linxrf.html)
Linx LC Series - Radiation • Short wire or matched transmission line to antenna • Antenna mounting • Antenna (nominal) length • Quarter wave: L [inches] = 234 / F [MHz] • Antenna Styles: • Whip • Helical • Loop • Stub • Just a wire
Linx LC Series - Other Issues • VSWR – voltage standing wave ratio, ideal form: • Rho is the reflection coefficient (RC) going into the antenna:
Modular RF - Other Issues • More radiation, more reliable link • Ground plane • Clean power supply • But maybe not too much • Note EMI/FCC issues ♦