Novel TCAS (Traffic Collision Avoidance System) local oscillator design method

Abstract

The invention relates to a novel TCAS (Traffic Collision Avoidance System) local oscillator design method which makes an improvement on the existing condition that two local oscillators are used in the traditional system and designs a novel TCAS local oscillator based on the multi-loop and frequency-mixing phase lock technology. The local oscillator comprises four parts: a large step frequency generation unit, a small step frequency generation unit, a frequency-mixing phase lock loop and a control circuit, wherein the large step frequency unit generates local oscillation signals of the frequency-mixing phase lock loop; the small step frequency unit generates reference signals of the frequency-mixing phase lock loop; an error lock prevention circuit is arranged in the frequency-mixing phase lock loop; and a controller generates signals of 1030 and 1090 MHz by controlling the frequency dividing ratio of a phase lock loop frequency divider and can fast switch between the two signals. The local oscillator provided by the invention has the advantages of low cost, simple structure, high stability and the like.

Description

Technical field [0001] The invention relates to a small airborne collision avoidance system, which belongs to the fields of air traffic management and air traffic safety. Background technique [0002] The anti-collision system on the aircraft, the American aviation system is called the air traffic warning and anti-collision system (hereinafter referred to as TCAS), and the European aviation system is called the airborne collision avoidance system. The meaning and function of the two are the same, and the composition is basically the same. Similar, therefore, the description of the application of the present invention is described with TCAS as the technical background. [0003] After years of development, TCAS system has developed a variety of models, such as: TCAS I, TCAS II, TCAS III, TCAS IV. Among them, TCAS II is currently the most widely used. It can provide aircraft pilots with traffic reminders (TA) that display information such as relative altitude, distance, azimut...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the disadvantages of high cost and large volume of the existing dual local oscillator design, the present invention designs and provides a new type of TCAS local oscillator that can replace the original dual local oscillator source with fast frequency conversion by using multi-loop and frequency mixing phase-locked technology source;

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