Kiefer  Electronic  Development - WIRELESS

     RF Engineering Consultancy - Richard Kiefer, Principal

Erbtec radio frequency power amplifiers are used to drive the coils in the General Electric magnetic resonance imaging system (MRI).  Some of the amplifiers produced by Erbtec are transistor units and others are tube type amplifiers operating at several kilowatts of pulsed output.  The transistor amplifiers typically use Motorola MOSFET's and the tube amplifiers use Eimac ceramic triodes and tetrodes.  KED has contributed to the design of both tube type and transistor amplifier modules.  One transistor design, for a research MRI system, generates 15 KW at 175 MHz.   

Key Client Product Benefits -

• High reliability as a result of computer modeling.
• Latest radio frequency design technology.
• Innovative circuit design.
• Innovative radio frequency transformer design.

Our Design Contribution -

KED assisted in the design of the basic 300 watt solid state "brick" for a power summed 15 KW 175 MHz power amplifier for magnetic resonance imaging research at the University of Alabama.  The output transformers were crucial for efficient operation of this amplifier.  Other KED magnetics designs for a 21 MHz solid state amplifier produce high efficiency at 5 KW output.  KED has also performed extensive PSpice modeling of a 10 KW Eimac tube amplifier for the 2-11 MHz range.

Contact - Richard Kiefer: 303-449-4700 (Colorado, USA - MST)