Thursday, October 8, 2009

Implantable Antennas/Power Amp Design

I attended the AnSys/Ansoft Smart Engineering Simulation Application Workshops earlier this week in Newton, MA. They had a complete RF/microwave track including sessions on Electrically Large Antennas and RCS; Statistical Modeling, DOE and Optimization; HFSS Tips and Techniques; RF Power Amp Design Using Coupled Circuit, EM and Thermal Analysis; Method of Analysis for Implantable Antenna Systems and RF Product Mgmt. Road Map and Dialog.

The Power Amp Design was very interesting as they showed how you can model the chip and package separately and merge the results to simulate the device. Then with a link to AnSys Mechanical, you can make a full model for thermal analysis and evaluate the performance. This allows you to trade of electrical and mechanical/thermal parameters to optimize device performance which is pretty powerful.

I also was intrigued by the Implantable Antenna Systems presentation given by Cambridge Consultants local here to the Boston area in Cambridge, MA (and headquartered in Cambridge, UK). They discussed how most of the radiation energy from a wireless signal is lost just by exiting the body due to losses in the tissues it goes through (especially fat) and reflections due to the changes in interfaces (fat, skin, tissue, etc. have large changes in permittivity). This loss also varies tremendously person to person depending on their build, etc. so over 99% of the energy is typically lost.

Therefore it is very important to have a optimized antenna system to maximize the gain and sensitivity of the signal. They use magnetic coupling for these applications since most of the energy is lost but the typical range requirement is 2 m. The FCC medial band used is 401-405 MHz but sometimes they used the unlicensed 2.4 GHz band for wake up since the FCC only allows 25 micro Watts ERP (if using an agile signal) for the medical band. Another design concern is a shift in frequency from the fat layer which varies by individual so they have to design for a broader bandwidth.

They have designed patch antennas that greatly improve sensitivity over the typical loop antenna currently used in many applications. The patch antenna results in about 3.4% of the radiated power while the loop antenna is only about 0.6% and the patch has better coverage. All of this has to fit into an enclosure about an inch square.

There were some very interesting applications that were presented here and it is very good to see the interaction with their customers as they strive to solve to their problems.

Wednesday, October 7, 2009

Power Amp Market to Double with MIMO 802.11n

Strategy Analytics reports that adoption of 802.11n MIMO with multiple transmit streams will help boost the market for Wi-Fi power amplifier modules to twice its 2008 size despite continued pricing pressure.

“As prices for single-stream 802.11n (1 x 1) chips dropped to match 802.11g, OEMs have quickly begun to switch from 802.11g to 802.11n in new products. Consequently, 802.11n will ship in more than half of all Wi-Fi systems by the end of 2010,” says Christopher Taylor, Director of the RF and Wireless Components service.

Not only will 802.11n quickly replace 802.11g, but as Wi-Fi continues to proliferate in new devices and applications, multi-stream MIMO configurations of 802.11n (i.e. 2 x 2, 3 x 3 and 4 x 4, transmit x receive) will rapidly grow in support of demand for greater range, faster file transfers and streaming multimedia in many of these applications.

SiGe Semiconductor has established a firm lead in power amplifiers despite increasing competition from GaAs PA module specialists such as Skyworks, RFMD, TriQuint and Anadigics. “A relatively small and nimble company, SiGe Semiconductor owes much of its success to concentrating its resources almost exclusively on Wi-Fi PA modules,” notes Asif Anwar, Director of the Strategy Analytics GaAs and Compound Semiconductor market research service.

I am impressed that SiGe has done well in target markets against some of these larger companies. They seem to have identified the markets that best fit their core technology.

Monday, October 5, 2009

Introducing xMax®--the world’s first mobile VoIP network

This came across my desk and I thought it was worth sharing - Chris Whiteley, director of business development for xG® Technology, will be one of the presenters at the COMPTEL Conference next week in Orlando, Florida. COMPTEL members are entrepreneurial companies building and deploying next-generation networks to provide competitive voice, data, and video services.

Whiteley will be on the Monday afternoon panel examining “Emerging Technologies.” He will present information on xMax®--the world’s first mobile VoIP network, which allows consumers to benefit from much lower-cost mobile calls via the Internet.

xG Technology developed xMax as an alternative solution that enables consumers to benefit directly using mobile VoIP technology. xMax is similar to Vonage or Skype, but in the form of a fully mobile handset that doesn’t require the use and extra cost of a computer or broadband Internet connection.

xMax offers consumers the prospect of lower phone bills because:
• xMax transmits over unlicensed spectrum—the same as baby monitors and cordless phones. Major national cellular carriers paid billions of dollars for licensed spectrum that they recoup from customers.
• xMax was built as a totally Internet-based digital system from top to bottom—an extremely cost efficient communication approach.

xMax networks can enable communication providers to aggressively compete with national carriers by offering customers unlimited voice and data plans both locally and long distance, extremely low-cost international calling, no contracts, as well as home phone and high-speed Internet service.

xMax is the product of xG Technology's extensive R&D activity, a $100 million international effort that involves companies in the US, Europe and Asia. xG's impressive patent portfolio, which includes 50 US and more than 100 international patents and pending patent applications, has been developed with the goal of bringing lower-cost communications to consumers.

To experience this new technology in the Ft. Lauderdale area, xG has deployed an urban/suburban showcase, which allows accredited journalists, published telecom analysts, and prospective partners to test the xMax platform at highway speeds.

Unique/Novel Subjects at EuMW 2009

I like searching through the paper/poster topics for unique, novel subjects that are not main-stream and might be areas for future growth. I was able to attend a few of these talks but was busy with customer visits covering the exhibition which made it impossible to attend more of them. Here are some that I came across:

  • Design of a Cellular Energy Harvesting Radio
  • New Fabrication Process to Manufacture RF-MEMS and GaN on GaN/Si Substrate
  • Design of a Fully Planar Chipless RFID Transponder with 35 Bit Data Capacity
  • SP48T Module Architecture RF-MEMS Multi-Throw Switches for a Multi-Beam Antenna Measurement Setup at K- and Ka-Band
  • A W-Band MMIC Vector Modulator Utilizing Tandem Couplers and 50 nm MHEMTs
  • Design and Characterization of a Novel Battery-less, Solar Powered Wireless Tag for Enhanced-Range Remote Tracking Applications
  • A Wideband OOK for Wireless Receiver Capsule Endoscope
  • Analysis of New Polarizing Properties of Negative Indexed Materials at Microwave Frequencies
  • RF Devices Written with Carbon Nanotube Ink on Paper
  • A Novel Fabrication Process for Printed Antennas Integrated in Polymer Multi-Layer Car Body Panels
  • UWB Frequency Modulated CW Synthetic Aperture Radar for Through-the-Wall Localization
  • Computer Simulation of the RF System Effects on a mmWave
  • Doppler Radar for Human Vital-Sign Estimation

One that I attended that was very interesting was the Design of a Planar Chipless RFID Transponder where they are trying to integrate low cost, rugged tags on money in Australia. They print chipless tags onto money that are comprised of 2 UWD antennas and a multi-section resonator to improve security and prevent counterfeiting. The goal is to get the cost down to about one cent so it is feasible to tag currency.

A very interesting conference this year with interesting topics – Let us know what you found interesting this year in the technical sessions or tutorials.