Development of new tests of electronic scanning radar microwave range

Introduction.

Antenna theory and technology devices largely determine the progress of science in areas such as radar, space communications and radio navigation. Many radio antennas are often fully determine their maximum achievable performance, such as range, bandwidth, accuracy of coordinate determination, resolution, etc. In some cases the antenna can also combine functions and transceiver - the so-called active antennas. A variety of types of antennas are now extremely high, but one of the main types of antennas are reflector antennas. A widespread receive reflector antenna in the microwave range.

Goals and objectives

Development of new antenna systems, antenna systems design for electronic scanning radar. Search and development of these structures antenna systems based on previously obtained research results and patents.

Urgency

Currently state radar, communications, radio astronomy is different hardware implementation of complex systems, which are an integral part of the antenna system. Currently antenna technology reached its peak of development. And in recent years because its development is underway to improve performance and use of new materials. With this in mind, the emergence of new ideas in antenna technology due to the need to create radio with desired characteristics [1].

Often in electronic systems must change position antenna pattern in space: support of the (goals), the search object (goal), etc. Such problems led to the term "scan". Scanning is: mechanical, electromechanical and nemahanichne [2].

When mechanical scanning beam moving in space are moving across the antenna. So with the antenna scanning are the most sluggish. Compared to other scanning methods such antennas have a relatively low speed, resolution, bandwidth, jamming. To turn these antennas using powerful engines, thanks to them taking place in parasitic currents create a strong magnetic field.

When electromechanical scanning mechanically moved only some elements of the antenna, and the main part of the antenna (primary mirror) remains still. The classic example is the position of the beam parabolic antenna radiator in moving or auxiliary mirror. But in such antennas are rotating joints, auxiliary engines, which aggravate the antenna performance [2].

Such shortcomings led to the development of antenna systems with electric scanning. Among electrically scanned antenna widespread and phased antenna arrays (FAR) and the desire to increase the radiation power and jamming led to the creation of active headlights. But implementation of the proposed requirements is impossible without improving signal processing methods. Electrical scanning enables high-speed review of the environment while maintaining relatively low side lobe and high pereshkodozahyschenosti.

Over the past decade

FAR became increasingly used in various systems. In the process of developing FAR is their shortcomings. Primarily using FAR difficult sweeping space, lower gain antennas in a loss of antenna elements: fazovraschateli, excitation devices, etc..

Energizing emitters is FAR or via feeder lines, or using the redistributable waves (in things quasioptical FAR) violations feeder highways near fazovraschatelyami sometimes contain complex electrical devices (things diagram schemes), provide excitation of emitters from multiple inputs, allowing a space corresponding to these inputs simultaneously scanning beams (in multi-FAR). Kvaziopticheskie FAR basically two types: pass (lens), which fazovraschateli and major emitters excited (assisted radiators) propagating waves of the total radiator, and chops - the main and auxiliary heaters are combined, and outputs fazovraschateley installed reflectors. Bahatopromenevi kvaziopticheskie FAR contain several irradiator, each of which corresponds to a beam in space. Sometimes, the FAR for the formation of NAM focuses on applying devices (mirrors, lenses). Considered above FAR sometimes called passive.

Greatest possible control characteristics have active lamps where each emitter module connected or controlled by a phase (sometimes amplitude) transmitter or receiver. Office of the active phase of FAR may be in tracts of intermediate frequency or in violation of coherent chain of transmitters, heterodyne receivers, etc. Thus, active FAR fazovraschateli can operate in wavelengths, other than the antenna frequency range; fazovraschatelyah losses in some cases directly affect the level of the main signal. Transmission active headlamps can make a drawing in space power coherent electromagnetic waves generated by individual transmitters. In foster active FAR common signal processing adopted by certain elements to obtain more complete information about the sources of radiation.

A result of direct interaction between the characteristics of emitters FAR (coordination emitters of excitatory feeder CPV etc.) when changing the beam oscillation. To combat the harmful effects of mutual influence of radiators in FAR sometimes use special methods compensate mutual coupling between elements.

This state of matterstimulates search of new designs electrically scanned antenna which new methods of signal processing.