Compensation of target signal migration in the multichannel matched filter

The study proposes a method of target range signal compensation within different pulse burst periods during in-period matched filtering. The proposed method allows to reduce losses in case of long-term signal integration. This is especially important for signals highly sensitive to Doppler frequency shift. In terms of this parameter, a multichannel configuration of the compression filter is a probable solution for such signals. Based on the example of a signal with non-linear frequency modulation and the results of simulation modelling, we analyse the effectiveness of migration compensation and give recommendations on channel multiplexing for the compression filter with an integrated migration compensator.

Effectiveness of target signal migration compensation at compression filter output

The paper describes a case study with the target moving at unknown radial velocity. Exemplified by the frequency modulation signal, the study presents the analysis of specific features of channel multiplexing for the target range migration compensator at the compression filter output within pulse burst periods. Channel multiplexing allows to reduces losses in case of long-term signal integration. The solution effectiveness is estimated and a method is proposed for compensator channel multiplexing ensuring protection against unwanted signal expansion.

Silicon Wafer Etching Rate Characteristics with Burst Width Using 150 kHz Band High-Power Burst Inductively Coupled Plasma

The high-speed etching of a silicon wafer was experimentally investigated, focusing on the duty factor of 150 kHz band high-power burst inductively coupled plasma. The pulse burst width was varied in the range of 400–1000 µs and the repetition rate was set to 10 Hz. A mixture of argon (Ar) and carbon tetrafluoride (CF4) gas was used as the etching gas and injected into the vacuum chamber. The impedance was changed with time, and the coil voltage and current were changed to follow it. During the discharge, about 3 kW of power was applied. The electron temperature and plasma density were measured by the double probe method. The plasma density in the etching region was 1018–1019 m−3. The target current increased with t burst width. The etching rate of Ar discharge at burst width of 1000 µs was 0.005 µm/min. Adding CF4 into Ar, the etching rate became 0.05 µm/min, which was about 10 times higher. The etching rate increased with burst width.