178 research outputs found
Tunable periodic microstrip structure on GaAs wafer
Get PDFA one dimensional tunable periodic structure in microstip technology on gallium arsenide (GaAs) substrate is numerically investigated. The unit cell contains a number of patches positioned between the ground plane and the microstrip line. The patches, representing reactive loads, can be selectively short-circuited by externally-controlled FET switches integrated in the hosting substrate. The possibility of controlling the position of the band-gap, and implicitly the value of the e®ective dielectric constant along the line, for different combinations of the switches is demonstrate
5G Extender Antenna Systems to Enhance Indoor Millimetre-Wave Reception
Get PDFExtender. Antenna. Systems. to. Enhance. Indoor. Millimetre-Wave. Reception. Dushmantha Thalakotuna and Karu P. Esselle Abstract Use of millimeter-wave spectrum in 5G result in small cell coverage due to inherent high free-space ..
Effects of a Coplanar Waveguide Biasing Network Built Into the Ground Plane on the Dispersion Characteristics of a Tunable Unit Cell With an Elliptical Patch and Multiple Vias
No full textThe effect of the biasing network (BN), formed by coplanar transmission lines (CPWs) built into the ground plane itself, on the dispersion characteristics of a tunable unit cell (UC) is investigated. The UC consists of an elliptical patch and multiple vias placed inside a parallel plate waveguide. One of the vias attached to a patch positioned on the top surface of a dielectric substrate connects the patch to the ground plane. Another via, symmetrically positioned with respect to the patch center, can be connected to the same ground plane or let to float depending on the state of a diode positioned at its base. The effect of the different components of the BN is analyzed step by step. For each intermediate configuration, the corresponding dispersion diagram (DD) is computed, allowing extraction of fundamental information on the influence of each part of the CPW circuit on the band-gap characteristics. The orientation of the BN is also discussed. The presented results can guide the dispersion engineering process when a tunable electromagnetic band-gap (EBG) structure is designed for a specific guided-wave applicatio
Oblique Incidence Performance of UWB Frequency Selective Surfaces for Reflector Applications
No full textpaper 436.
Implantable 400MHz PIFA for bio-telemetry system
No full textA miniaturized implantable antenna, to be implanted in small animal, designed for Medical Implantable Communications Services (MICS), is presented in this paper. The proximity couple-fed technique is applied to enhance the bandwidth of the antenna to overcome the out-of-band probability of the antenna due to frequency detuning by the surrounding tissue and encapsulation. The aim of this research is to transmit the extracted physiological signals from the body of a small animal wirelessly to an external RFID reader (400MHz) connected to a computer via USB cable. The overall dimensions of the antenna are 32mm×22mm×4mm and the ground plane of RFID tag is utilized to improve the performance of the antenna. Animal tissue model has been developed and the antenna is encapsulated by a bio-compatible material before putting it in this model. Effect of encapsulation material is explored in this paper which may be utilized to retune the antenna if needed. The predicted bandwidth of the proposed implanted antenna is found as approximately 8
Holography-based RCS reduction by surface-wave engineeringof a conformal flexible substrate with periodic structures
No full textpaper IF 322.
Metamaterial-based millimeter-wave switchableleaky wave antennas for on-chip implementation in GaAs technology
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