I. Maestrojuan

Fourth-Harmonic Schottky Diode Mixer Development at Sub-Millimeter Frequencies

This paper presents the design, fabrication and measurements of a fourth-harmonic Schottky diode mixer working at sub-millimeter frequencies, in particular at an RF frequency of 440 GHz. Measured DSB noise temperature of 7900 K and conversion loss of 14 dB have been obtained. This configuration offers an alternative solution which simplifies the LO signal generation. It can find an application in imaging systems, where arrays of detectors need to be simultaneously fed by the same LO.

A broadband radiometer configuration at 94GHz in planar technology

This paper describes a broadband radiometer receiver configuration in planar technology working around 94 GHz. This differential configuration allows reducing gain and noise temperature fluctuations of the amplifiers themselves in a wide bandwidth, which improves the sensitivity of these systems. In addition to this, the studied configuration also allows obtaining as an output a reference signal amplified in the same way that the unknown RF signal. Therefore, the system can be easily calibrated. The different components of the RF front-end of the receiver have been optimized for an operational bandwidth of 80–100 GHz.

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.