Terahertz and millimetre wave imaging for wall painting investigation

Abstract

The Terahertz imaging technique was applied to observe the preparation layer of wall paintings. The experimental results revealed the effect of the particle size of fillers and the possibility of internal interface observation by the THz pulse-echo imaging.

A novel gain‐boosting structure with Z‐embedding and parallel pre‐embedding network for amplifiers at near‐fmax frequencies

“…Since the Y-parameters of the core device are given, by sweeping B p1 , solutions of the required B p2 and X f can be obtained according to (9) and (10). In Figure 6A, the required value of B p2 and X f is presented when B p1 is sweeping from À0.2 to 0.2.…”

“…Due to the demand for high-speed communication, the terahertz communication system that can provide higher than 20 Gb/s data rates attracts more and more attention. [1][2][3][4][5][6][7][8][9][10][11][12] However, since the working frequency of the terahertz communication system gets close to the maximum oscillation frequency (f max ) of a silicon-based transistor, the intrinsic gain of an active device decreases rapidly. It makes the silicon-based terahertz amplifier without any gain-boosting techniques exhibit poor power amplification capacity, thus not able to meet the demand of the system requirements.…”