An 800 MHz frequency synthesizer for land mobile radio equipment

Abstract

AbstractIt is important to develop a frequency synthesizer that does not require a sophisticated multiplier and which oscillates directly at the local oscillation frequency for use as a local oscillator, with a view to the simplification and miniaturization of a large‐capacity land mobile radio equipment. The mobile frequency synthesizer is required to have a high purity oscillation, fast channel‐switching and high stability when subjected to mechanical vibration. A 1000‐channel switchable type frequency synthesizer with direct oscillation and direct division at 800 MHz has been developed to satisfy these requirements, based on consideration of an 800 MHz voltage‐controlled oscillator of high purity and optimum circuit design of a phase synchronizer. This synthesizer consists of an 800 MHz voltage‐controlled oscillator, two synthesizer LSIs and a crystal oscillator. In comparison with the conventional 150 MHz frequency synthesizer, it is only 1/9 as large. This paper describes the design and performance of this 800 MHz frequency synthesizer.