Electronic circuit capable of stably keeping a frequency during presence of a burst
First Claim
1. In an electronic circuit comprising controlling means responsive to a frequency deviation signal for producing a frequency control signal, frequency producing means responsive to said frequency control signal for producing a local oscillation signal of a variable frequency, and burst generating means for generating a burst in response to an input signal, said local oscillation signal, and a burst control signal which is present during the presence of said input signal and which has a beginning and an end, said burst appearing between the beginning and the end of said burst control signal, the improvement wherein said circuit further comprises:
- holding means responsive to said frequency control signal and said burst control signal and coupled to said controlling means and said frequency producing means for holding the frequency control signal received before the beginning of said burst control signal to keep said frequency of the local oscillation signal invariable until the end of said burst control signal.
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Accused Products
Abstract
In a radio communication system, a transmitting section of a substation comprises a controlling circuit (21) for controlling a carrier frequency of a local oscillator (24) in response to a frequency deviation signal. A burst generating circuit (26) generates a burst in response to the input signal, a burst control signal, and a local oscillation signal of the carrier frequency. The transmitting section further comprises a holding circuit (34) responsive to a frequency control signal and the burst control signal. During presence of the burst control signal, the holding circuit holds the frequency control signal received before a beginning of the burst control signal to keep the carrier frequency of the local oscillation signal invariable until an end of the burst control signal. Otherwise, the frequency control signal passes through the holding circuit as it stands. Consequently, the carrier frequency of the local oscillation signal is controlled only during absence of the input signal and is kept invariable during presence of the input signal.
92 Citations
4 Claims
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1. In an electronic circuit comprising controlling means responsive to a frequency deviation signal for producing a frequency control signal, frequency producing means responsive to said frequency control signal for producing a local oscillation signal of a variable frequency, and burst generating means for generating a burst in response to an input signal, said local oscillation signal, and a burst control signal which is present during the presence of said input signal and which has a beginning and an end, said burst appearing between the beginning and the end of said burst control signal, the improvement wherein said circuit further comprises:
holding means responsive to said frequency control signal and said burst control signal and coupled to said controlling means and said frequency producing means for holding the frequency control signal received before the beginning of said burst control signal to keep said frequency of the local oscillation signal invariable until the end of said burst control signal. - View Dependent Claims (2, 3, 4)
Specification