Instructor Arturo Mediano has written an article for In Compliance magazine:
Digital and power electronic systems can reduce the radiated and conducted emissions profile using spread spectrum techniques. Typically, no more than 10-12dB can be obtained with those techniques but the result can be useful to comply with regulations...
Instructor Arturo Mediano has published an article with In Compliance magazine on reducing VHF EMI from a flyback power supply.
Usually, EMC design guidelines in flyback literature are related with the switching effects of the output transistor to minimize emissions for conducted tests in the 9 kHz to 30 MHz range. But failure in radiated emissions in the VHF range is typical when testing the product for EMC compliance.
Until now, the focus in developing wireless communications formats has been almost exclusively on using novel techniques to overcome specific channel impairments (i.e. multipath, selective fading, etc). What has been missing is an assessment of the overall energy efficiency of the final hardware that is to be deployed. This paper introduces this type of analysis.
Instructor Earl McCune's presentation from the 2014 IEEE MTT symposium in Phoenix, AZ is available for downloading from the IEEE website. This presentation looks at the problem of providing high efficiency and linearity from a power transistor at the same time.
Operating Modes of Dynamic Power Supply Transmitter Amplifiers
Any amplifier operated with a varying supply voltage is actually a three-port circuit, having two inputs and one output. When an amplifier is characterized as a three-port for dynamic supply voltage operation, three separate operating modes...