The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
CONSERT is the radar on the ROSETTA (ESA) cometary mission, which the primary goal is to investigate the deep interior of the nucleus of comet 67/P. The radar had operated between the spacecraft and Philae lander. An electromagnetic wave loses energy as it propagates through the cometary nucleus and travels at a smaller velocity than in free space. Thus, any signal that has propagated through the...
In this paper, designs of both circular and octagonal microstrip patch antennas are presented on the Substrate Integrated Waveguide (SIW) for X- Band Applications. Both antennas are modelled and simulated using the full -wave simulator CST MWS. It can be concluded that the proposed antenna designs are able to achieve high gain and directivity with the miniature, compact, light, cost effective and...
Herein, design and experimental results of a dual band Microstrip Monopole antenna are presented. The proposed antenna consists of a zig-zag microstrip line as monopole patch alongside of a Defected Ground structure under the fed-line of the antenna for size miniaturization propose, fabricated on FR4. The 10-dB bandwidth and gain performances are measured as 130 MHz and 6 dB at the centre frequency...
A brief introduction of the gyrotron is given focusing on the design of the magnetic system design. A discussion about various possible solutions for the magnetic system is undertaken and the advantages and disadvantages for the each example are given. Requirements for the construction are presented and justification for the choice of the given solution is provided. Initial design simulations for...
A method for achieving frequency synchronization between two distantly positioned high frequency oscillators is presented. The method is based on using GPS disciplined 10 MHz reference sine waves and phase locked dielectric resonator oscillators. In order to be able to measure the frequency difference between high frequency sources precisely, frequency down-conversion by a mixer is implemented. The...
Recent developments in SAR data processing have paved the way towards more and highly flexible imaging modes and significant improvements with respect to area coverage and resolution. Here, for instance Digital Beam Forming (DBF) will enable the development of SAR missions which mitigate the old ‘area-for-resolution’ trade-off. Furthermore, the recent 1200MHz frequency allocation by ITU for commercial...
The analytical models for optical imaging of internal structure of controlled objects with complex shape were considered and, on their basis, the distortions, appearing in the image depending on visualization system's parameters and emitting source type, were analyzed.
Direct detection mm/sub-mm wave warm-carrier bipolar narrow-gap Hg1−xCdxTe semiconductor bolometers that can be used as sensitive elements in THz sensitive arrays, are considered. The response of Hg1−xCdxTe warm-electron bolometer was measured in ν=0.037−1.54 THz frequency range at T=68-300 K. In the detector (bolometer) considered the electromagnetic wave heats electrons and holes there, creates...
A broadband rat-race coupler has been designed in a suspended stripline technique. For broadband operation the needed phase inverter has been realized as a shorted-coupled-line section. Additionally single section matching transformers have been added to improve the return losses. The suspended stripline technique has been chosen for minimizing the coupler's losses. The described circuit has been...
Terahertz spectral investigations on drug candidates with similar molecular structures to their chemical and physical parameters are described and newly-synthesized derivatives of some bi-heterocyclic compounds are examined. Using chemometric techniques we evaluate their spectral similarity in the THz range. Principal Component Analysis (PCA) is used to solve the problem.
The new type of narrowband bandpass filter is presented. The design and realization of the filter in microstrip technology is described. The filter has been etched from YBCO thin film deposited on sapphire substrate. The filter has bandwidth of 0.2 %, RL better than 20 dB and a size of 2 inch in diameter. The structure consists of coupled half-wavelength resonators with additional cross couplings...
This paper describes the project of a low-noise 1.3 GHz PLL synthesizer designed to synchronize a 1.3 GHz DRO to 100 MHz reference signal. This synthesizer was built for the Master Oscillator of the European XFEL project. Designed prototype incorporates both a mixer and a sampling phase detector circuits to compare phase noise performance.
This paper presents a heterodyne measurement system of the pulse-to-pulse (P2P) stability and its application to time-domain measurements of a GaN HEMT microwave power amplifier. Envelope and P2P stability measurements are performed for an irregular RF pulse train which integrates a long silence between each pulse sequence. This paper is focused on the impact of RF pulse width and duty cycle on each...
We report on epitaxial growth, processing, characterization and firsts photoresponse experiments performed on GaN/AlGaN lateral Schottky barrier diodes. The epitaxial GaN/AlGaN epistructures were fabricated by molecular beam epitaxy under metal rich conditions on the freestanding GaN substrates. The lateral Schottky barrier diodes were performed using modified transistor processing, which was based...
UWB Pentagon antenna is designed to detect brain stroke and brain tumour. It is operating at a band from 3.3568– 12.604 GHz in free space and from 3.818 to 9.16 GHz on the normal head model. The antenna has dimensions of 44×30mm2. It is fabricated on FR4-substrate with relative permittivity 4.4 and thickness 1.5mm. The antenna is simulated on the CST Microwave Studio and measured using the network...
In this paper, design and experimental results of a coplanar stripline fed Microstrip Yagi-Uda antenna are presented. The proposed antenna consists of a microstrip line to coplanar stripline transition, reflector microstrip patch, coplanar stripline-fed driver dipole, and three director microstrip patches on low-cost FR4 with the relative permittivity 4.4, thickness 1.58mm, loss tangent 0.025. The...
We demonstrate a radio-frequency electromagnetic signal detection in spintronic devices utilizing various magnetoresistance effects. Different device layout is proposed such as tunneling magnetoresistance nano-pillar or giant magnetoresistance stripe, which enable DC voltage generation when a device is supplied with radio-frequency current. Depending on the detection method, sensitivity of up to 80...
This paper presents a compact dehydration measurement method, keeping in mind a system integration in a wristwatch housing. In contrast to the conventional measurement approach using two measurement antennas, the proposed measurement setup uses only one antenna and one metallic reflector. Measurements have been performed using a patch antenna immersed in a steel basin filled with a tissue-equivalent...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.