Zhou Zhiquan

Study on scattering characteristics of chaff for radar

In this paper, polarization scattering characteristics of chaff are investigated based on dipoles scattering model. Scattering cross section (SCS) and radar cross section (RCS) are respectively defined considering practical operating mode of radar systems. The results show that various formulas of chaffs RCS existing in different documents are classified definitely. Chaffs RCS applicable to various radar systems are discussed.

Study of High-Speed Pseudo-random Code Generator Whose Sampling Interval is Not 2i

This paper presents a new method for high-speed generation of pseudo-random code, which is based on sampling and parallel-to-serial conversion. This method can be used in situation that the sampling interval does not equal to , which increases the sampling selectivity and system adaptability. Finally, we verify the algorithm based on FPGA and the result is consistent with our prediction.

Novel Method for QDDFS with Super High Compression Ratio

A novel method for quadrature direct digital frequency synthesizer with ten millions compression ratio, which is based on the Taylor expansions of sine and cosine, is firstly put forward. The traditional DDFS architecture is changed while accumulator is replaced by phase tipster in this system. Through this excellent method, super high frequency resolution is achieved. At last, a simple configuration of this system is presented

Quadrature Direct Digital Frequency Synthesizer with High Compression Ratio

This paper presents a new QDDFS architecture with high compression ratio, which based on the principles of non-linear approach and trigonometric approximation. The principles have been analyzed systemically and all the parameters have been optimized. A high compression ratio of 762 at 93.5 dBc in a 16 bit system. The architecture is realized by Quartus-II at maximum clock frequency of 100 MHz. In the end, a proposed architecture is given.

Angle estimation for two closely spaced targets with polarization monopulse radar

The measurements of the two-closely spaced targets are merged when the target echoes are not resolved in angle or radial velocity. Conventional monopulse radar will only obtain single DOA measurement of the centroid. The paper provides an approach to extract direction-of-arrival (DOA) of the target. This method is simple and effective, though it requires complex measurements of signal and a priori knowledge of the polarization scattering characteristics of interference.