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This paper proposes a broadband circularly polarized antenna that is composed of inverted F and L antennas on the ground plane, and is allocated in a rotational symmetry. The height and diameter of our proposed antenna is respectively 0.10λ0 and 0.33λ0. The relative bandwidth satisfied with VSWR<3 in each band is 10.7% and 6.9%.
A new type of broadband miniature antenna consists of helical dipole folded by central conductor is presented in this paper. Besides a brief analysis, the experimental results show the good performances of wider bandwidth (25%–40%), higher input impedance(about 200 Ohms), and flexible for designing, it is suitable to be used as both mobile vertical antenna and excitor of Yagi antenna.
This paper presents a discussion on current developments in the design and manufacture of Global Positioning System (GPS) antennas at Chu Associates Inc. The primary focus will be the description of different antenna profiles, broadband characteristics, pattern coverage, axial ratio and VSHR. Consideration will also be given to antenna suitability for use in normal or high accuracy positioning systems...
This paper presents a high-gain 6–40 GHz circularly polarized antenna system designed for a 6U CubeSAT mission for monitoring RF emission from earth. The antenna system consists of three quasi-tapered helical antenna elements, operating at 6–11 GHz, 11–22 GHz and 21–40 GHz, respectively. Each antenna element is designed to produce an end-fire beam with its helical diameter varying along its axis to...
This paper presents recent developments in metaline-based antennas. Four metalines are presented and application of these metalines to low-profile antennas is discussed: (A) zeroth-order metaline antenna, (B) double metaline antennas, (C) metaloop antennas, (D) metaspiral antennas, and (E) metahelical antennas. Wideband broadside radiation from double metaline antennas and dual-band counter circularly-polarized...
This paper investigates the validation of a modeling software for helical antennas. One of the benefits of the stepped helical antenna, which consists of two or more cylindrical helices of different diameters, is its capability, under some conditions, of providing a large bandwidth. It is also simpler and cheaper than a tapered helix. For spacecraft applications, a theoretical design of such an antenna...
Helical antenna is a practical electromagnetic radiator constructed by winding a conducting wire in the form of a screw thread. In most applications, the helix antenna is mounted on a ground plane as shown in Fig. 1. The radiation characteristics of the helix antenna are critically dependent on the electrical size of its geometrical properties. The input impedance is dependent upon the pitch angle...
A wideband circularly polarized (CP) strip-helical dipole antenna is presented in this paper. Two tapered strip-helixes with one turn are placed over a ground plane and symmetric to each other with respect to the Z-Axis. Each of them is respectively fed with same magnitude and phase difference of 180° thus the whole radiator works as a helical dipole. Numerical results show that the proposed strip-helical...
In this work, a novel design tor a tully on-chip 3D antenna operating at 4 THz that can be fabricated by a novel MEMS (micro electro mechanical systems) technology directly realized on a silicon substrate is presented. The antenna includes two parts, the metallic helix and the microstrip on the substrate for feed. The proposed antenna structure is well suitable designed by MEMS technology, the fabrication...
A wideband printed quadrifilar helical antenna (PQHA) using a novel single layer compact feeding circuit is proposed in this paper. A low cost single layer feeding circuit is consists of a 180° compact rat race coupler and two 3 dB hybrid commercial couplers to be incorporated at the bottom of the quadrifilar antenna. The operating frequency band ranges from 2 to 2.3 GHz which represent the proposed...
A design of a 15:1 bandwidth single-mode two-arm spiral helix antenna is presented. In order to achieve unidirectional and efficient radiation, the spiral is cavity backed and resistively loaded. A trapezoidal pyramid cavity is implemented for higher gain at the turn on frequency and smoother gain variation at higher frequencies. Numerical simulations are conducted to assess the gain and axial ratio...
A wideband strip-helical antenna with a parasitic circular patch for circular polarization is designed in this paper. A strip-helix with 2.5 turns and a pitch angle of 5° is placed over a ground plane and coaxial probe-fed by a 50-$\Omega $ SMA connector. A parasitic patch is electromagnetic-coupled to the open end of the strip-helix with an extremely small distance. By combining the strip-helix...
A wideband millimeter-wave antenna backed by an elliptical cavity for circularly polarized radiation, excited by a dipole inclined to the major axis direction of the cavity, is reported in this letter. Experimental results show that the proposed antenna can achieve a bandwidth of 50–62.8 GHz for both axial ratio and reflection coefficient ...
Analyses on the diameter of the ground plane of helical antennas show that, when the diameter of this plane is slightly smaller than the one of the helix itself, backfire radiation is achieved. Considering this ground plane as a director, the addition of more ground planes - or directors - is proven to increase the directivity of the antenna. With these reduced ground planes not causing any blockage...
This paper introduces a pattern reconfigurable wideband circularly-polarized (CP) quadrifilar helical antenna (QHA) with both broadside and backfire radiation modes. A compact 1∶4 power divider network is proposed to feed the QHA for obtaining the wide bandwidth. To realize pattern diversity, PIN diodes on the power divider are to reconfigure the sequences of the output phases such that the direction...
This paper presents design, fabrication and measurement results of a novel broadband, circularly polarized, planar helix antenna operating at X-band that is fabricated using printed circuit techniques. The conventional circular helix antenna is modified into a planar helix antenna, and the effect of various parameters like pitch angle, dimensions, feed and substrate, etc. on the impedance and radiation...
A wideband conical printed tapering quadrifilar helical antenna for Global Navigation Satellite System (GNSS) is presented. By wrapping four printed tapering helical strips on the surface of modified hollow conical dielectric rod and using wideband network with stable amplitude and phase distribution to feed, the proposed antenna are effectively designed to achieve wide bandwidth, desired gain and...
A design approach of multiband and wideband antennas for radio apparatus is presented. The antenna is consisted of a monopole, a folded loop, and a helix. The fundamental behaviors of the single element and their combinations are analyzed to give desired bandwidths per the mutual coupling between elements. The presented antenna structure is a good starting point to be familiar with the multiband antenna...
Compact monocone antennas loaded with helical resonators are presented. The proposed loading introduces an anti-resonance nearby the original resonance of the cone reducing the turn-on frequency by ∼22%. Moreover, the antenna maintains a decade bandwidth with good impedance match and consistent patterns. By terminating the helical posts with 50Ω loads, an impedance match is maintained to very low...
Helical antennas are versatile, but they have almost purely resistive input impedance, so lumped element matching networks inevitably incur power loss. We investigate an alternative matching technique that claims up to 1∶1 VSWR with post-fabrication tuning, by using an extension above the ground plane. However, our results show that the lowest return losses may actually occur outside the desired band...
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