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This paper summarizes work performed within the Polish applied research project THzOnLine aiming at multi-pixel THz detectors based on selective NMOS transistors and its application in biology, medicine and security systems. The techniques applied for increasing the efficiency of THz detectors, as well as issues related to development of the readout electronics for these devices are discussed in the...
We propose a method for making THz detector antenna gain frequency dependency smooth by using conductive substrate. However, an increase of substrate conductivity decreases antenna gain even if an insulation layer is present.
In this paper the presented research work analyzes the effects of electromagnetic (EM) radiation of mobile phone on human head. The EM radiation is measured based on Specific Absorption Rate (SAR). The human head is generally exposed to mobile phones operating at communication (GSM, CDMA etc) frequency bands. The radiation absorption analyzed through simulations by applying frequency domain using...
A thin and ultra-wideband metamaterial absorber comprising single-dielectric substrate is investigated in this paper. The proposed structure contains a ground plane and relies on the bianisotropic properties of the unit cells forming the absorbing layer. This structure is realized as an array of periodic conducting circular loops and L-shaped strips with lumped resistors. Lumped resistors are used...
This paper presents a compact Koch fractal loop antenna designed for ambient radio frequency (RF) energy harvesting at GSM1800 band. Novel impedance matching method is proposed by using an embedded metal plane (EMP) within the loop. Comparing to the conventional loop antenna, the antenna with EMP has a bit lower resonance frequency and the input impedance can be easily matched to 50 Ohm. The metal...
Experimental and theoretical investigations of the influence of substrate thickness on the performance of Si field effect transistor terahertz detectors are presented‥ We show that in the case of planar metal antennas a significant portion of incoming radiation, instead of being coupled to the transistors, may be coupled to the substrate leading to important responsivity losses‥ The ways of avoiding...
New microstrip antenna derived from the first iteration of Sierpinski fractal portions has been designed in this study as semi-fractal structure. This antenna has been designed using single layer substrate and dual via ports to operate with resonant frequencies at 2.55, 3.02 and 7.08 GHz within 2 to 8 GHz frequency range. The proposed antenna has miniature dimensions with good radiation performances,...
The paper presents the research on open microstrip structures placed on curved surfaces such as cylindrical, elliptical or spherical. The numerical analysis of investigated structures is based on expansion of electric and magnetic fields into suitable function series. Utilizing the continuity conditions the boundary problem is formulated which is solved with the use of method of moments. The investigated...
A wireless power transfer system is conceived to empower light drones and unmanned aerial vehicles. To satisfy the power budget of the wireless link and provide enough power to the drone, new circuits based on directive frequency-scanned leaky-wave antennas and circuits are proposed. It is shown how the proposed leaky-wave devices introduce enough gain in the receiver system, while assuring reception...
Dual band THz-IR receivers can be used in application within different fields. For instance, in radio-astronomy, dust emission in the infrared (IR) and submillimeter wave or THz ranges is used for star-formation characterization. This information is normally acquired by different detectors which operate at each of these frequencies; i.e. Terahertz and Infrared. The development of an integrated dual...
In this paper the theoretical maximum tuning range of a frequency-reconfigurable antenna based on a half-mode substrate-integrated cavity is investigated and discussed. The antenna, which has recently been proposed by the authors, demonstrated a measured frequency tuning range of about 42% based on the capacitance range offered by practically available varactors. In the present investigation, the...
We outline the possibilities of 3D direct write dispensing and brush-painting in the manufacturing of copper UHF RFID tags on textile and cardboard materials and present considerations regarding the process parameters to achieve high-performance tags when the copper antenna is deposited directly on these rough and porous materials. Our measurement results confirm that the additively-manufactured copper...
The growth of the Internet of Things has created a need for cost-effective and light-weight electronics on flexible substrates. Great potential lies in versatile applications of passive UHF RFID components but their robustness toward various environmental stresses must be ensured. This paper presents a comparison of thermal- and inkjet-printed passive UHF RFID tag antennas on a novel polyester-based...
This paper will review techniques of manufacturing wearable antennas. 3D printing can be used to create flexible substrates. 3D shapes can be created which can be used to reduce the antenna size. Embroidery will also be discussed. The technique naturally lends itself to linear antennas.
The efficiency of electromagnetic power re-radiation by a wirelessly interrogated passive sensor and its sensitivity to the measured value are the main factors defining the sensor performance. The analysis gives the relation between the re-radiation efficiency and the electromechanical coupling factor. Experimental resonator parameters demonstrate the relevance of this efficiency improvement. The...
A circular polarization-reconfigurable (CPR) monopole antenna for Global Navigation Satellite System (GNSS) applications is proposed. The CPR antenna consists of two meandered monopoles denoted as MP1 and MP2, a switchable feeding network, and a metasurface (MS) using dual-cap mushroom-like unit cells. The two monopoles have tapered shapes for better matching and wider impedance bandwidth. The switchable...
In this paper, a novel planar reconfigurable monopulse antenna with compact size is proposed and studied for indoor smart wireless access points (WAPs) application. Circular polarization is achieved by using a dual-mode substrate integrated waveguide (SIW) slot antenna. Two diagonal ports are individually used to excite the SIW element antenna to achieve a 180° phase-shifting excitation. A reconfigurable...
A Nematic Liquid Crystal (N-LC) compound may be injected into a cavity beneath a printed patch antenna to act as a tunable material whose dielectric properties are controlled by an externally applied electric field. The strength and direction of the applied low-frequency field affects the orientation of the LC molecules known as directors. The orientation of the directors determines the dielectric...
This paper presents integrated, distributed on-chip antennas. The aim is to achieve a higher system bandwidth due to the utilization of multiple antennas and the combining of their frequency ranges. All designs will be manufactured in the 130nm IHP SG13G2 process. Furthermore the measurement setup is described and measurement results are shown.
Sensor elements play an important role in future manufacturing plants. This paper presents a solution for a foil thickness sensor for running production lines. Based on the elaborated Six-Port principle, a differential measuring concept is proposed and discussed. Furthermore, an end-fire antenna design for the addressed application is demonstrated and far-field measurement results are shown and compared...
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