Vehicle audio distortion measurement system
First Claim
1. An audio frequency distortion measurement system for measuring the response of a motor vehicle audio system to noise caused by a motor vehicle components, comprising:
- a generator that generates RF signals and transmits said RF signals to a motor vehicle RF receiver through a communication link;
said RF receiver including an electrical output for driving a speaker;
a controller coupled to said generator that controls transmission of said RF signals to said receiver and selectively activates the motor vehicle component; and
a distortion analyzer coupled to said RF receiver electrical output and said controller that senses and analyzes audio distortion in response to signal analysis commands that are output from said controller;
wherein said distortion analyzer is commanded to analyze the audio output distortion caused by said motor vehicle component.
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Accused Products
Abstract
A radio frequency audio distortion measurement system for a motor vehicle radio. The system includes a generator that generates test RF signals and transmits the signals to the motor vehicle radio through a wireless communication link. The system includes a controller coupled to the generator that controls the transmission of the RF signals to the radio. The system also includes a distortion analyzer coupled to the RF receiver and the controller that senses and analyzes the audio distortion caused by motor vehicle system components, such as motor vehicle electrical and electronic system components, in response to commands output from the controller. The system of the present invention thereby provides an objective way of analyzing audio distortion caused by radiated conducted and/or coupled interference from electrical and electronic systems in a controlled test environment.
28 Citations
26 Claims
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1. An audio frequency distortion measurement system for measuring the response of a motor vehicle audio system to noise caused by a motor vehicle components, comprising:
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a generator that generates RF signals and transmits said RF signals to a motor vehicle RF receiver through a communication link; said RF receiver including an electrical output for driving a speaker; a controller coupled to said generator that controls transmission of said RF signals to said receiver and selectively activates the motor vehicle component; and a distortion analyzer coupled to said RF receiver electrical output and said controller that senses and analyzes audio distortion in response to signal analysis commands that are output from said controller; wherein said distortion analyzer is commanded to analyze the audio output distortion caused by said motor vehicle component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of testing radio frequency (RF) signal distortion created by motor vehicle system components, comprising:
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placing a motor vehicle in a test cell; activating a motor vehicle RF signal receiver; transmitting an RF signal to the motor vehicle RF signal receiver via the test cell; selectively activating certain motor vehicle system components; and measuring audio signal distortion caused by the selectively activated motor vehicle system components. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. A system that analyzes audio distortion output by a motor vehicle radio as a result of motor vehicle component interference, comprising:
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an FM RF signal generator that generates test FM RF signals; an AM RF signal generator that generates test AM RF signals; a switching device coupled to the FM RF signal generator and the AM RF signal generator such that selective switching between the RF signals is provided; a transverse electromagnetic (TEM) test cell that provides an isolated motor vehicle test environment, said TEM cell including a septum coupled to said switching device for transmitting said selected RF signals to a motor vehicle radio inside said TEM test cell; a radio tuning actuator in operative communication with the motor vehicle radio to selectively tune the frequency of the receiver; a distortion analyzer operatively coupled to the motor vehicle radio through a communications bus that evaluates audio signals output from the radio for motor vehicle induced distortion and generates signal distortion data relating thereto; said communications bus including an optical isolator to permit the measurement of signals without affecting the circuit being measured; and a controller operatively coupled to said RF signal generator and said distortion analyzer for controlling system operations.
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Specification