Radiation Pattern

In this paper, a printed Yagi antenna with an integrated balun is proposed for CubeSat communications. The printed antenna is mechanically adjustable to realize three functional states at different operating frequencies in the L-band and S-band respectively. Three different angle deployments are proposed at 10°, 50° and 90°, so that the antenna operates at three different operating frequencies, namely 1.3 GHz (L-band), 2.4 GHz (S-band) and 3 GHz (S-band). The measured results of the fabricated antenna are well matched with the simulation, having frequencies of 2.82–3.07 GHz, 1.3–1.4 GHz and 2.38–2.57 GHz, with similar radiation patterns. The measured gain of the antenna is 8.167 dBi at 2.4 GHz, 5.278 dBi at 1.3 GHz and 6.120 dBi at 3 GHz. Keeping within the general theme of cheap off the shelf components for CubeSats, this antenna design allows the CubeSat designers to choose from three popular frequencies, through a simple angle configuration. The main contribution of this work lie...

Microlens array (MLA) diffusers for light-emitting diode (LED) backlight systems have been developed. A high fill-factor photoresist mold for the MLA was fabricated using three-dimensional diffuser lithography, and the patterns were transferred to a nickel master mold for UV-curable polymer replication. The fabricated microlens had various paraboloidal profiles, and its aspect ratio was controlled from 1.0 to 2.1. The MLA diffuser showed a batwing radiation pattern with a radiation angle of 150 degrees. The fabricated MLA diffuser may greatly enhance the color-mixing characteristics of LED backlight systems and help reduce the number of LEDs required.

Improving the of radio telescopes and ra- diometers and their associated receive subsystems translates into increasing the ground received signal-to-noise ratios. Therefore, low noise amplification with cooling operation is required. How- ever, the system designer must select an appropriate feedhorn antenna with low sidelobes and an adapted illumination at the edge of the reflector since the noise originated from the

... Domenico Gardini1, Maria di Donato2 & Enzo Boschi2 1 Dipartimento di Scienze Geologiche Universit`a di Roma Tre, I-00146, Italy (now at Institut für Geophysik, ETH, Zürich, CH-8093, Switzerland) 2 ... tion: MW = 2/3 log(M0)-9.09 (with M0 expressed in dyne cm; Kanamori, 1977 ...

Materials with unconventional values of permittivity and or permeability have been the object of intense research in the last few years. For example, artificial materials with simultaneously negative permittivity and permeability have received significant attention due to their potential breakthroughs in subwavelength imaging and miniaturization of several devices. Recently, our research group has been particularly interested in the study of a different class of materials characterized by a 'low'permittivity as compared to the ...

An Axial-Mode Helical Antenna (AMHA) design for applications in Doppler-based continuous non-contact vital signs (NCVS) monitoring sensor systems is presented. Two methodologies of on-reflector impedance matching are presented as a solution to the helical antennas' non-50Ω input impedance issue. The antennas are evaluated on their performance of VSWR, impedance, radiation pattern directivity, size and gain. A size reduction design process is given for custom sizing the helical antenna, and the resulting structures are compared versus a patch antenna at 2.4GHz that is often used in NCVS systems. Our test data indicates that an AMHA can significantly increase accuracy of NCVS systems by increasing the system's Signal-to-Noise-and-Interference Ratio (SNIR).

A Microstrip Patch Antenna is a type of radio antenna with a low profile, which can be mounted on a low surface. It is a narrow band, wide-beam fed antenna fabricated by etching the antenna element pattern in metal trace bonded to the dielectric Substrate such as a printed circuit board with a continuous metal layer bonded to the opposite side of the substrate which forms a ground plane. The main aim of this work is to design, develop and test the Printed Circuit antenna (Microstrip Patch antenna) suitable for use in L-band frequency range of 1-2GHz. This study also emphasizes on simulation of micro-strip patch antenna using IE3D software to simulate & study the radiation pattern & other radiation pattern parameters and comparison with specifications/requirements. Co-axial Feed technique was adopted and the location of the feed point was varied within the radiating patch to arrive at the point of minimum return loss. This work is also focused on characterization of fabricated antenna in view of parameters like VSWR, Antenna efficiency, Axial ratio, Gain and radiation pattern.

ABSTRACT This paper proposes a dual-band circular polarization (CP) monopole antenna. This antenna can generate a broadband impedance-bandwidth from 2.17 to 8.47 GHz, and excite a left-hand circular polarization (LHCP) at 2.48 GHz and right-hand circular polarization (RHCP) at 3.90 GHz. The measured 3-dB axial ratio (AR) bandwidths are about 140 MHz from 2.41 to 2.55 GHz approximately 5.6% with respect to the center frequency at 2.48 GHz and 900 MHz from 3.45 to 4.35 GHz approximately 23.1% with respect to the center frequency at 3.90 GHz.

In this paper, on-body propagation modelling has been investigated applying various numerical computational techniques. Propagation measurements with body-worn antennas have been carried out at 2.4 GHz inside and outside an anechoic chamber respectively for narrowband communication channel characterisation. Both simulation and measurement results have been also obtained at the UWB (ultra wide-band) band.

Abstract—A novel design of a dual-polarized broadband 2–18GHz horn antenna with VSWR≤2.2 is presented. The designed horn antenna is most suitable as a feed element in reflectors of the radar systems and EMC applications. A coaxial line to quadruple-ridged waveguide ...