Ford Global Technolgoies, LLC

Ford Motor Company Limited

Vincent Colarossi

John F Kennedy

Matt David Gerard

A radio frequency amplifier includes a first amplifier stage having a first transistor, and a second amplifier stage having a second transistor. The first transistor has a base input for receiving an input voltage, a collector output, and an emitter coupled to a common. The second transistor has a base input coupled to the first transistor collector output, a collector output, and an emitter coupled to the common by a resistance element. The second transistor emitter is DC coupled to the first transistor base. The DC coupling of the first transistor base to the second transistor emitter provides stable DC biasing of the first and second transistors based on base-emitter voltages of the first and second transistors. The radio frequency amplifier may be employed in a variety of receiver/amplifier applications, such as vehicular driver integrity check systems.

Low power RF amplifier

A liquid level indicating system particularly applicable to monitoring the fuel level in a motor vehicle includes an anti-slosh feature incorporated into a system amplifier to substantially eliminate fluctuations in the fuel level indicated by a fuel gauge driven by the amplifier. The anti-slosh feature is provided by limiting the slew rate of the amplifier during normal operation of the system. The slew rate is limited by using a limited current source to provide dc bias current within the amplifier such that the output can change only at the limited slew rate. To make the system respond rapidly upon start up of a vehicle including the system, the normally limited current source is supplemented by a secondary current source which provides substantially higher dc bias current within the amplifier and accordingly a substantially higher slew rate for the amplifier. The secondary current source is activated for a defined period of time to allow the fuel gauge to initialize, and then is disabled such that the amplifier is thereafter slew rate limited to correct for fuel slosh.

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Dearborn, MI, United States of America

Vincent Colarossi