Woo-Kyung Lee

A new pulse compression technique generating optimal uniform range sidelobe and reducing integrated sidelobe level

A novel pulse compression technique is developed that produces an optimal uniform range sidelobe of the ideal Barker code level. The newly obtained sidelobe pattern provides an optimal compromise between the range resolution and the peak sidelobe level (PSL), regardless of the signal code length, and also retains the merit of strong resistance to the Doppler shift effect. Very low sidelobe regions appear around the mainlobe peak, which is useful in target tracking and recognition. A novel processing technique is proposed to reduce the ISL energy. A sidelobe canceller is generated directly from the incoming signal and combined together with the original pulse compression output in which unwanted sidelobes are significantly eliminated.

Fano resonance in a two-level quantum dot side-coupled to leads

We theoretically study Fano resonance in a two-level quantum dot side-coupled to two leads, which are connected by a direct channel. The resonance lineshape is found to be deformed, from the conventional Fano form, by interlevel Coulomb interaction and interlevel interference. We derive the connection between the lineshape deformation and the interaction-induced nonmonotonicity of level occupation, which may be useful for experimental study. The dependence of the lineshape on the transmission of the direct channel and on the dot-lead coupling matrix elements is discussed.

Optimal sampling of linear FM and conversion to digitized waveform having predictable sidelobe patterns

Several advantages are achieved when discrete phased codes are used instead of continuous waveforms. The discrete structure of the phase code signal enables one to increase the freedom of waveform design when pulse compression scheme is considered. This may lead to an arbitrary design of the resultant sidelobe patterns and possibly wide dynamic range responses can be achieved for various applications. This paper shows how a particular sampling rate for linear FM signals may lead to a significant reduction of the peak sidelobe level (PSL) as well as the integrated sidelobe level (ISL) in pulse compression operation.