Motorola Corporation

Robert Martin Beckmann

Robert J Karschnia

William Arthur Burzynski

Fred Alan Reimers

Dennis Eugene Tomlinson

William Henry Schwartz

Chad Michael Mcguire

A frequency synthesizer is disclosed in which a single read only memory (ROM) is utilized to directly control programmable frequency dividers in a phase locked loop while also directly controlling the excitation of seven segment visual digital display modules. During the tuning of the frequency synthesizer, an enable circuit disables the programmable dividers while altering the input signals to the read only memory such that direct drive signals are produced by the output of the read only memory which alternately excite two separate seven segment displays modules. After the tuning operation is completed, the enable circuit alters the input signals to the read only memory, simultaneously enables the programmable dividers, and effectively disables the digital display modules such that they hold their previous visual displays.

Frequency synthesizer with ROM controlled divider and display

The synthesizer uses phase lock loop techniques to generate either the carrier signal for an associated transmitter or the injection signal for an associated receiver. A programmable divider controls the specific channel to which the synthesizer tunes the transmitter or receiver whereas operation in the transmit or receive mode is dependent upon which of two oscillators is coupled in the synthesizer circuit. The oscillators are designed to run at two frequencies having a difference equal to the intermediate frequency of the receiver. This allows the one output from the synthesizer to be used in both the transmit and receive modes.

Synthesizer

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Hanover Park, IL, United States of America

Robert Martin Beckmann