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US 7,253,682 B2Granted
Antenna amplifier
AssigneeRobert Bosch GmbH
InventorsHans-Joachim Raddant, Ralf Schultze
Life of this patent
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Abstract
The antenna amplifier for mobile FM radio reception includes a signal amplifier, a controllable adjusting element having a PIN diode for impedance adaptation, and a control amplifier for regulating the adjusting element. The antenna amplifier has a compensation for the temperature response occurring as a result of very great differences (summer/winter) in ambient temperature, the PIN diode connection point is optimized, and the control range is maximized.
Claims18
An antenna amplifier for mobile FM radio reception, comprising:
- a signal amplifier;
- an adjusting element including:
- at least one PIN diode for adapting an impedance of an antenna to an impedance of a signal amplifier,
- a first adaptation system for adapting the impedance of the antenna to an impedance of the at least one PIN diode, and
- a second adaptation system for adapting the impedance of the at least one PIN diode to the impedance of the signal amplifier;
- a control amplifier for regulating the adjusting element;
- four resistors, wherein:
- the operational amplifier of the control amplifier and the four resistors form a subtracter having a first input voltage at a second input and a second input voltage at a first input of the control amplifier;
- and
- two diodes representing voltage sources connected in series with inputs of the operational amplifier, each of the two diodes being traversed by an approximately identical quiescent current that is determined by respective voltages and resistors, the two diodes being thermally coupled in mechanical fashion in such a way that the two diodes have approximately identical temperature coefficients, wherein:
- a HF voltage coupled out at an output of the signal amplifier produces at one of the two diodes a rectified voltage that is amplified by a factor;
- wherein the control amplifier includes:
- a rectifier for a rectified voltage, and
- an operational amplifier that amplifies the rectified voltage.
11 more elements
An antenna amplifier for mobile FM radio reception, comprising:
- a signal amplifier;
- an adjusting element including:
- at least one PIN diode for adapting an impedance of an antenna to an impedance of a signal amplifier,
- a first adaptation system for adapting the impedance of the antenna to an impedance of the at least one PIN diode, and
- a second adaptation system for adapting the impedance of the at least one PIN diode to the impedance of the signal amplifier;
- a control amplifier for regulating the adjusting element;
- a capacitor;
- three resistors, wherein:
- the operational amplifier of the control amplifier, the three resistors, and the capacitor form an integrating subtracter having a first input voltage at a first input and a second input voltage at a second input of the control amplifier;
- and
- two diodes representing voltage sources connected in series with inputs of the operational amplifier, each of the two diodes being traversed by an approximately identical quiescent current that is determined by respective voltages and resistors, the two diodes being thermally coupled in mechanical fashion in such a way that the two diodes have approximately identical temperature coefficients, wherein:
- a HF voltage coupled out at an output of the signal amplifier produces at one of the two diodes a rectified voltage that is amplified by a factor;
- wherein the control amplifier includes:
- a rectifier for a rectified voltage, and
- an operational amplifier that amplifies the rectified voltage.
12 more elements
An antenna amplifier, comprising:
- a controllable adjusting arrangement, which includes:
- at least one PIN diode for adapting an impedance of an antenna to an impedance of a signal amplifier,
- a first adaptation system for adapting the impedance of the antenna to an impedance of the at least one PIN diode, and
- a second adaptation system for adapting the impedance of the at least one PIN diode to the impedance of a signal amplifier;
- a control amplifier coupled to the controllable adjustable arrangement to control the controllable adjustable arrangement, the control amplifier including:
- an amplifier and resistor arrangement, wherein the amplifier and resistor arrangement form a subtracter to provide a first input voltage at a second input and a second input voltage at a first input of the control amplifier, and
- a diode arrangement to represent voltage sources coupled in series with inputs of the amplifier of the amplifier and resistor arrangement, each diode of the diode arrangement being thermally coupled so that each of the diodes has approximately the same temperature coefficient.
4 more elements
Dependencies are inferred from the claim text.