Microwave Engineering Europe - September 2008 - (Page 27) TEST — RF AMPLIFIER PERFORMANCE 27 Figure 6: EVM versus RF frequency results in more detail. The lower graph shows the amplifier gain versus frequency (blue line). The upper graph is the EVM versus frequency. The upper red trace labeled “Distorted Plot” is the amplifier EVM, showing that the EVM does not degrade with frequency. The lower green trace labeled “Baseline Plot” is the analyzer EVM. which are effectively a set of sub-carriers operating at different frequencies each transmitting a unique symbol but transmitted simultaneously. For this modulation scheme, multiple constellations are generated and multiple modulation techniques are used. Here the computed EVM is an RMS composite of the EVM from all the carriers and all the transmitted symbols. At any point in time, the combined symbol states can create very large or very small power outputs depending on the phases of the individual states making up the transmission. This is where it is critical to set the power amplifier operating point to minimize the power amplifier’s operation in the gain compression range. As the EVM versus power analysis showed, operating in the gain compression range severely degrades EVM and modulation quality. Benefits of SDR The architecture and the technologies used in the vector signal analyzer and vector signal generator are based on state-of-the-art designs called software-defined radio (SDR). In SDR, analog circuits are replaced with fast and powerful digital processing circuitry. These designs are more flexible, since measurement RF Solutions from JFW Industries • Programmable Attenuation Systems • Fixed Attenuators & Terminations • Programmable Attenuators • RF Test Accessories • RF Matrix Switches • Rotary Attenuators • RF Power Dividers • RF Switches JFW Industries, Inc. Call 317-887-1340 Toll Free 877-887-4539 E-mail: sales@jfwindustries.com Visit: www.jfwindustries.com Microwave Engineering ● September 2008 ● www.mwee.com 023-024-025-026-027-028_MWEE.indd 27 3/09/08 16:59:02 http://www.jfwindustries.com http://www.jfwindustries.com http://www.mwee.com
Table of Contents Feed for the Digital Edition of Microwave Engineering Europe - September 2008 Microwave Engineering Europe - September 2008 News Contents Comment Cover Feature: Uncovering Test and Measurement’s Role in Advancing LTE and Mobile WiMAX WiMax: WiMax and LTE Need to Address Issues of Backhaul, Cost and Efficiency for Successful Deployment WiMax: Manufacturing Communications Technology Products in India Test and Measurement Mobile Platforms Evolve to Meet Future Demands Products Calendar Microwave Engineering Europe - September 2008 Microwave Engineering Europe - September 2008 - Microwave Engineering Europe - September 2008 (Page Cover1) Microwave Engineering Europe - September 2008 - Microwave Engineering Europe - September 2008 (Page Cover2) Microwave Engineering Europe - September 2008 - Microwave Engineering Europe - September 2008 (Page 3) Microwave Engineering Europe - September 2008 - News (Page 4) Microwave Engineering Europe - September 2008 - News (Page 5) Microwave Engineering Europe - September 2008 - News (Page 6) Microwave Engineering Europe - September 2008 - Contents (Page 7) Microwave Engineering Europe - September 2008 - Contents (Page 8) Microwave Engineering Europe - September 2008 - Comment (Page 9) Microwave Engineering Europe - September 2008 - Comment (Page 10) Microwave Engineering Europe - September 2008 - Comment (Page 11) Microwave Engineering Europe - September 2008 - Cover Feature: Uncovering Test and Measurement’s Role in Advancing LTE and Mobile WiMAX (Page 12) Microwave Engineering Europe - September 2008 - Cover Feature: Uncovering Test and Measurement’s Role in Advancing LTE and Mobile WiMAX (Page 13) Microwave Engineering Europe - September 2008 - Cover Feature: Uncovering Test and Measurement’s Role in Advancing LTE and Mobile WiMAX (Page 14) Microwave Engineering Europe - September 2008 - Cover Feature: Uncovering Test and Measurement’s Role in Advancing LTE and Mobile WiMAX (Page 15) Microwave Engineering Europe - September 2008 - WiMax: WiMax and LTE Need to Address Issues of Backhaul, Cost and Efficiency for Successful Deployment (Page 16) Microwave Engineering Europe - September 2008 - WiMax: WiMax and LTE Need to Address Issues of Backhaul, Cost and Efficiency for Successful Deployment (Page 17) Microwave Engineering Europe - September 2008 - WiMax: WiMax and LTE Need to Address Issues of Backhaul, Cost and Efficiency for Successful Deployment (Page 18) Microwave Engineering Europe - September 2008 - WiMax: WiMax and LTE Need to Address Issues of Backhaul, Cost and Efficiency for Successful Deployment (Page 19) Microwave Engineering Europe - September 2008 - WiMax: Manufacturing Communications Technology Products in India (Page 20) Microwave Engineering Europe - September 2008 - WiMax: Manufacturing Communications Technology Products in India (Page 21) Microwave Engineering Europe - September 2008 - WiMax: Manufacturing Communications Technology Products in India (Page 22) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 23) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 24) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 25) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 26) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 27) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 28) Microwave Engineering Europe - September 2008 - Test and Measurement (Page 29) Microwave Engineering Europe - September 2008 - Mobile Platforms Evolve to Meet Future Demands (Page 30) Microwave Engineering Europe - September 2008 - Mobile Platforms Evolve to Meet Future Demands (Page 31) Microwave Engineering Europe - September 2008 - Mobile Platforms Evolve to Meet Future Demands (Page 32) Microwave Engineering Europe - September 2008 - Mobile Platforms Evolve to Meet Future Demands (Page 33) Microwave Engineering Europe - September 2008 - Products (Page 34) Microwave Engineering Europe - September 2008 - Products (Page 35) Microwave Engineering Europe - September 2008 - Products (Page 36) Microwave Engineering Europe - September 2008 - Products (Page 37) Microwave Engineering Europe - September 2008 - Products (Page 38) Microwave Engineering Europe - September 2008 - Products (Page 39) Microwave Engineering Europe - September 2008 - Products (Page 40) Microwave Engineering Europe - September 2008 - Products (Page 41) Microwave Engineering Europe - September 2008 - Calendar (Page 42) Microwave Engineering Europe - September 2008 - Calendar (Page Cover3) Microwave Engineering Europe - September 2008 - Calendar (Page Cover4)
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