Huanyao Dai

Main-Lobe Jamming Suppression Method of using Spatial Polarization Characteristics of Antennas

As interferences are introduced from a main-lobe direction, which results in target signals being masked by interference, traditional adaptive beamforming and eigen-subspace projection methods cannot suppress main-lobe interferences effectively. A novel interference suppression method is proposed that processes the sample data by using the scanning property of a single polarized antenna. The orthogonal polarization decomposition and polarization estimation of the receiving signal based on the spatial polarization characteristics of the antenna are realized so that the interference is diminished. The effect of an elevation measurement error on interference suppression performance is eliminated by design spatial multinotch virtual polarization filtering. Theoretical and simulation results show that it made single polarized radar own a polarization information processing ability that improved radar working performance.

A New Polarimetric Method by Using Spatial Polarization Characteristics of Scanning Antenna

Antenna polarization states always vary with scan direction. Here this phenomenon is called spatial polarization characteristic (SPC) of antenna. Based on the single polarized radar antenna, by sufficiently utilizing of the inherent polarization property of antenna (i.e. the property that polarization state is not a constant but a function of antennas spatial scanning direction), a novel polarization scattering matrix (PSM) measurement method is established. This method has the following advantages: (i) It does not need dual orthogonal polarization channels; (ii) the PSM of target can be obtained just by using the prior knowledge of SPC and by improving the signal processing mode of received radar signal. The modern radar systems can make use of this property in its measurement of target polarization scattering property in the searching or angle tracking stage.

Spatial polarization characteristics and scattering matrix measurement of orthogonal polarization binary array radar

Polarimetry is an important trend in the development of modern radar. The technique for measuring polarization scattering property of the target is the key for polarization radar realization, but it faces challenges in engineering. Here, a new theoretical model for target scattering characteristic measurement radar, named orthogonal polarization binary array radar (OPBAR), is proposed. The spatial polarization characteristics of the radar antennas are addressed. A new polarimetric algorithm that needs only one channel is designed. The polarization scattering matrix measurement can be implemented by processing received signal in a short time interval while antenna’s beam mechanically scans the target. Through compactness field microwave dark room experiment, measurments of dynamic broadband polarimetry on OPBAR have been conducted and the validity of research work has been demonstrated. The result is helpful to exploiting the capability of current radar systems and enhancing their information acquiring and processing capacity.

Novel research on main-lobe jamming polarization suppression technology

A novel main-lobe blanketing interference suppression method which named as spatial virtual multiple channel concurrent polarization filter technology is proposed. It processes sample data using the slow varied polarization property of a scanning antenna. The orthogonal polarized signal and polarization states of the receiving signal can be obtained. The optimal polarization is then calculated for use in polarization filtering to achieve the objective of suppressing noise jamming. The effect of elevation measurement error on interference suppression performance is eliminated by concurrent processing. Theoretical and simulation results show that, this technology enabled self-polarization information processing for single polarized radar which improved its working performance.

Spatial Polarization Characteristics of Phased Array

With rapid development of polarization measurement technology, vector signal process and microwave technology, polarization information is sufficiently used to provide a potential technical approach for impairment of influence of adverse electromagnetic environment on the radar system, resistance to active jamming, suppression of environmental clutter, anti-stealth and target recognition and other aspects, being capable of effectively improving working performance of modern radars.

Connotation and Representation of Spatial Polarization Characteristic

The concept of polarization is first defined in the field of optics, used to describe the phenomenon of directional oscillation of light. Therefore, it is also called directional oscillation. In fact, as a common nature of vector waves, polarization receives wide attention in the infrared, optical, radar and other fields. As far as radar is concerned, polarization describes the variation of the electric field vector of electromagnetic wave with time on the propagation cross section [1]. It reflects the vector characteristic of electromagnetic waves. Besides information of time domain, frequency domain and spatial, polarization is also available important information of electromagnetic waves.

Matrix Measurement Method Based on Antenna Spatial Polarization Characteristics

Radar target polarization measurement is a basic problem in the field of radar polarization technology. How to acquire polarization information is undoubtedly a basic problem in the investigation of the radar detection technology.

Antenna Spatial Polarization Characteristics Measurement and Calibration

Measurement of target polarization characteristics is an important basic issue for recognition of radar target characteristics and target identification, and is widely concerned for a long time. Radar target can be considered a polarization changer, which is usually represented by a second-order complex matrix, and is solved through “receiving and measuring two target echo signal under orthogonal polarization electromagnetic wave excitation on two orthogonal polarization basis in a simultaneous or time-sharing manner”. However, from the prospect of engineering implementation, there are many technical difficulties to develop special target polarization characteristics measurement radar, such as improving orthogonal polarization channel separation degree, maintaining consistency in amplitude and phase of several polarization channels, and solving calibration of polarization measurement system.

Blanketing Jamming Countermeasure Method Based on Spatial Polarization Characteristics of Antenna

In increasing complicated and adverse electromagnetic field in battlefield, survival ability and working performance of individual electronic information systems including modern radar, communication, navigation and reconnaissance systems faces increasingly stern challenges, so it is required to enhance anti-jamming ability, improve signal receiving quality and dig useful information to the highest extent.

Spatial Polarization Characteristics of Aperture Antenna

Antenna is the image and emblem of radar, which is closely related to the radar system. The design of new radar should first select the antenna system and scheme. There are many kinds of antenna, which can be roughly divided into two categories: wire antenna and aperture antenna. Wire antenna consists basically of metal wires. This category includes dipole antenna, monopole antenna, coil antenna, helical antenna, Yagi antenna, logarithm periodic antenna, and traveling-wave antenna. Aperture antenna also known as aperture antenna is usually an aperture in a plane or curved face. This category includes horn antenna, reflector antenna, slot antenna, and microstrip antenna.