Near Space Vehicle Uploaded Terminal Receiver Front-end Design And Implementation

In pace with development of the modern science and technology, especially that of new material, new power, new structure, new energy, and high-efficiency miniature electronic equipment, design technology of new aircrafts that can fly in the near space such as stratosphere airship and supersonic aircraft makes advance, which sets basis for exploiting the near space.This article originates from the project"equipment on aircraft in near space", which was held by CETC 10. The author developed the RF receiver in the equipment which will be loaded on aircraft in near space by adopting the structure of superheterodyne second conversion. This RF receiver is mainly composed of filter, low noise amplifier (LNA), mixer, automatic gain controller (AGC), and local oscillator, being up to the specification of high dynamic range required by equipment on aircraft in near space. Technology used in developing this RF receiver has some creative and special features.By consulting many internal and external RF receiver design documents, this article discusses basic principle of equipment on aircraft in near space theoretically, and then introduces development and realization of the high dynamic range RF receiver as a part of equipment on aircraft in near space, by use of some key technology such as mixer technology, local oscillator technology, and AGC technology.This article firstly compairs and analyzes several RF receiver structures, followed by introducing key technical specifications of RF receiver, and secondly presents a design program of RF receiver, with argumentation of technical specifications of this RF receiver, followed by detailing specific circuit design and realization in this project, and what should be noted in the process of circuit debugging. In the end, it gives test results.