Synthesizer

US4061973A · kind A · utility

Assignee

• Motorola, Inc. · US

Inventors

• Fred Alan Reimers · Lake in the Hills, US
• Robert Martin Beckmann · Bartlett, US
• William A. Burzynski · Des Plaines, US
• Dennis E. Tomlinson · McLeansboro, US
• William H. Schwartz · Delray Beach, US

Key dates

• Filing date: Mar 25, 1976
• Grant date: Dec 6, 1977
• Expiry date: Mar 25, 1996

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B1/50
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

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.