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US 4,395,776 AGranted
Transmitter having a phase synchronizing system
AssigneeToyo Communication Equipment Co., Ltd.
InventorsYukio Naito, Masahide Tamura, Shigeo Takahashi
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AssigneeToyo Communication Equipment Co., Ltd.
InventorsYukio Naito, Masahide Tamura, Shigeo Takahashi
Estimating the term…
A transmitter having a transmitting phase synchronizing system. To one input of a frequency mixer is applied the output of a phase synchronizing type digital frequency synthesizer, through a first frequency divider. A modulating signal is applied to another input of the frequency mixer. The output from the mixer is connected via a bandpass filter to a phase synchronizing system having in series, along a main route, a phase detector, a lowpass filter, and a voltage controlled oscillator, and thence to an amplifier system. In a feedback route from another outlet of the voltage controlled oscillator to the phase detector is a second fixed frequency divider. The digital frequency synthesizer itself may have a reference oscillator connected in series to a third fixed frequency divider, a second phase detector, a second lowpass filter and a second voltage controlled oscillator, from which a feedback circuit leads back to the phase detector via the first fixed frequency divider and a variable frequency divider.
A transmitter comprising a frequency mixer to one input of which is applied an output of a phase synchronizing type digital frequency synthesizer and to another input of which is applied an output of a phase or frequency modulator coupled to a side step oscillator, the output from said frequency mixer going to a bandpass filter, and from there to amplifying means via a phase synchronizing system having a phase detector connected to said bandpass filter and series connected to a lowpass filter and a voltage controlled oscillator as a main route, in which said voltage controlled oscillator is connected to said amplifying means, and a feedback route from said voltage controlled oscillator to said phase detector, said transmitter having in combination therewith a first fixed frequency divider between said phase synchronizing type digital frequency synthesizer for connecting said synthesizer to said frequency mixer, and a second fixed frequency divider connected in said feedback route of said phase synchronizing system.
A transmitter as claimed in claim 2, in which said phase synchronizing type digital frequency synthesizer comprises basically on a main route a series connected reference oscillator, a third fixed frequency divider, a second phase detector, a second lowpass filter, a second voltage controlled oscillator, and on a feedback route from said second voltage controlled oscillator to said second phase detector, said first fixed frequency divider and a variable frequency divider, said first frequency divider having an outlet signal that is branched, said variable frequency divider having fed to its input one branch of the output of said first fixed-frequency divider while the other branch is fed to said frequency mixer.
A transmitter comprising
Dependencies are inferred from the claim text.