U.S. Philips Corporation

U.S. Phillips Corporation

Jean A Chabas

A radio device includes phase discriminator with a phase locked loop. Where when there is no phase locking, the output voltage of the phase discriminator remains constant, which provides considerable gain for loop. When there is phase locking, the phase discriminator produces an error proportional to the phase difference. An output of the phase discriminator has a constant amplitude with an input signal and a reference signal have different frequencies.

Radio device including a frequency synthesizer and phase discriminator for such a device

This electronic apparatus comprises a power amplifier formed by an output stage (,) that has a non-linear amplification characteristic, and a correction assembly (,) for compensating for the non-linearities of said characteristic. This assembly is formed by a low-power preamplifier (,) of the same type as said power stage, consequently presenting the same non-linearity as stage (,). The combining device (,) combining the signals applied to the input terminal (,) with the output signals of said preamplifier (,) largely counteracts the non-linearities of said characteristics.

Electronic apparatus comprising a power amplifier

This device includes a frequency synthesizer (,) comprising two phase-locked loops (L,and L,). The one comprises a low-pass filter (,) and the other a high-pass filter (,). The loop with the low-pass filter fixes the basic frequency of the synthesizer and the other corrects the phase noise. With this arrangement it is easy to apply a modulation frequency to the terminal (,) that is not disturbed by said loops if this modulation frequency is found to be higher than the cut-off frequency of the low-pass filter.

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Cesson Sevigne, France

Jean A Chabas