EP0416423A2
Expired / Lapsed
EP
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An arrangement for the attenuation of radiofrequency interferences caused by the harmonics of the clock frequency of digital devices
Assignee: Nokia Oyj
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Filing: 1990-08-27
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Granted: —
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Expires: 2010-08-27
Abstract
Abstract The invention relates to a method and an arrangement for the attenuation of radio-frequency interferences caused by the harmonics of the clock frequency of digital devices, such as a microprocessor. According to the invention, the spectrum of the harmonics of the clock frequency is treated by modulating (U mod ) the clock signal (f CL ).
Inventors
- 👤 Reino Talarmo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 03:54
CPC Classifications
H; H04; H04B; H04B15/00; H04B15/02; H04B15/04; G; G06; G06F; G06F1/00; G06F1/04; H04B2215/00; H04B2215/064
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
40 words
A method of attenuating clock-frequency interferences caused by the harmonics of the clock frequency of digital devices, such as a microprocessor, characterized in that the spectrum of the harmonics of the clock frequency is processed by modulating the clock signal.
Claim 2
Independent Claim
40 words
A method of attenuating clock-frequency interferences caused by the harmonics of the clock frequency of digital devices, such as a microprocessor, characterized in that the spectrum of the harmonics of the clock frequency is processed by modulating the clock signal.
Claim 3
Dependent Claim
15 words
A method according to claim 1, characterized in that a clock oscillator is modulated directly.
Claim 4
Dependent Claim
19 words
A method according to claim 1, characterized in that the clock signal generated by the clock oscillator is modulated.
Claim 5
Dependent Claim
31 words
A method according to claim 1, 2 or 3, characterized in that the modulating signal is a continuous signal, such as a sinusoidal signal, or a signal having a pseudorandom waveform.
Claim 6
Dependent Claim
37 words
A method according to claim 1, 2, 3 or 4, characterized in that the front or the back edge or both of the clock pulse of the clock signal are displaced in the time domain by modulating.
Claim 7
Dependent Claim
34 words
An arrangement for attenuating interferences caused by the harmonics of the clock frequency of digital devices, such as a microprocessor, characterized in that it comprises means (C2, 22, 32) for modulating a clock signal.
Claim 8
Dependent Claim
34 words
An arrangement for attenuating interferences caused by the harmonics of the clock frequency of digital devices, such as a microprocessor, characterized in that it comprises means (C2, 22, 32) for modulating a clock signal.
Claim 9
Dependent Claim
62 words
An arrangement according to claim 6, characterized in that it comprises a crystal oscillator for generating a clock signal, a crystal (X1) in the crystal oscillator being connected to a serial or parallel resonance circuit in which at least one capacitive component is formed by a capacitance diode (C2) the capacitance of which is adjusted by a modulating signal (U mod ).
Claim 10
Dependent Claim
45 words
An arrangement according to claim 6, characterized in that it comprises a phase shift means (22, 32) connected in series with a clock signal source (21, 31), the phase shift caused by said phase shift means being modulated by the modulating signal (U mod ).
Claim 11
Dependent Claim
45 words
An arrangement according to claim 8, characterized in that the clock signal source (31) supplies a signal having a rectangular waveform, the phase shift means being formed by a digital divider circuit, preferably a fraction divider, the divisor of which varies with the modulating signal.
Claim 12
Dependent Claim
34 words
An arrangement according to any of the preceding claims, characterized in that the modulating signal (U mod ) is a continuous signal, such as a sinusoidal signal, or a signal having a pseudorandom waveform.
Claim 13
Dependent Claim
19 words
Use of an arrangement according to any of claims 6 to 10 in radio devices, particularly in radio telephones.
References Cited (Backward Citations)
No citation records indexed.
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