I. Palacios

Suicide bomber detection

The chance of suicide bomber attacks against troops in the Theatre of Operations is currently quite high. Most of the time checkpoints and compound gates are not equipped with the appropriate equipment to screen for potential suicide bombers. The ultimate solution would be to be able to perform stand-off screening under various weather conditions whilst avoiding contact between Force Protection personnel and potential suicide bombers. Radiation in the millimeterwave and the lower Terahertz range, having the useful property of being able to penetrate clothing in addition to fog and rain, makes it a clear candidate for imaging in this situation. A study has been made simulating real case scenarios to test practical detection performance and stand-off distances at a range of frequencies in this band, the results of which will be presented.

Active THz imaging system to measure water content evolution in leaves

Quality control systems in industry can benefit from the new possibilities offered by the THz frequency range. THz imaging systems can complement actual quality control systems and at the same time offer new information about products, improving quality and reducing costs. In this case we have implemented an imaging system to control the evolution of water content in leaves. The work presented in this paper shows the water content evolution of leaves in the range from 0.14 THz to 0.22 THz. Transmission and reflection parameters have been measured obtaining frequency and time domain information. While in the visible region the leaf is still green after 48 hours of cutting, and no appreciable change can be seen, in the THz image more than 5dB variation can be obtained due to the loss of water in the leaf. As a conclusion, it can be said that imaging in active THz technology can be used to measure the evolution of water content in leafs at the early stage of drying, where no changes are noticeable in the visible region. Agriculture quality control systems could benefit from this technology.

THz imaging system for industrial quality control

THz imaging technology can complement quality controls in Agricultural and food industry due to the new point of view offered by THz. In this paper, an active THz imaging system based on a network analyzer with two frequency extender up to 0.22THz and a quasioptical system is presented. The resolution of the system is measured using metal squares placed on a leaf. This metal squares are used to show differences in power absorption levels. Defects are also placed in one sample, in order to check the possibilities offered by THz imaging to detect unwanted objects and defects in a leaf.

Explosives characterization in terahertz range

A Thz spectral characterization of the behaviour of different explosives is presented in this paper. This characterization will be done in the frequency range from 20 GHz to 4 THz using a Teraview Spectra 3000. This system has a capacity of measuring from 20 GHz to 4 THz fed by a laser source. With the Teraview Spectra 3000 equipment will be possible to calculate the refractive index, the absorbance and other important parameters of the explosive samples. With this study it will be possible to characterize some of the most common used explosives, i.e., gun explosive, gunpowder mine, pent, TNT, RDX, etc, and it will allow to determine their electromagnetic peculiarities in order to design a future imaging system that allow detecting them in security and defense sectors.

Development of a sub-harmonic mixer working at 220 GHz

This paper describes the design and development of a heterodyne sub-harmonic receptor working at Sub-mm wave frequencies, which in this case it corresponds with 220 GHz. The design has been realized with different electromagnetic programs such as Ansoft HFSS and Ansoft Designer. Along this paper several modifications are going to be studied with the purpose of achieving a good prototype in terms of good adaptation at the OL and RF ports and low noise temperature and conversion loss.