Conical-beam Radiation Patterns Research Articles

A Low-Profile Circularly Polarized Conical-Beam Antenna with Wide Overlap Bandwidth

In this paper, a low-profile circularly polarized (CP) conical-beam antenna with a wide overlap bandwidth is presented. Such an antenna is constructed on the two sides of a square substrate. The antenna consists of a wideband monopolar patch antenna fed by a probe in the center and two sets of arc-hook-shaped branches. The monopolar patch antenna is loaded by a set of conductive shorting vias to achieve a wideband vertically polarized electric field. Two sets of arc-hook-shaped parasitic branches connected to the patch and ground plane can generate a horizontally polarized electric field. To further increase the bandwidth of the horizontally polarized electric field, two types of arc-hook-shaped branches with different sizes are used, which can generate another resonant frequency. When the parameters of the arc-hook-shaped branches are reasonably adjusted, a 90° phase difference can be generated between the vertically polarized electric field and the horizontally polarized electric field, so that the antenna can produce a wideband CP radiation pattern with a conical beam. The proposed antenna has a wide impedance bandwidth ( ∣ S 11 ∣ < − 10 dB ) of 35.6% (4.97-7.14 GHz) and a 3 dB axial ratio (AR) bandwidth at phi = 0 ° and theta = 35 ° of about 30.1% (4.97-6.73 GHz). Compared with the earlier reported conical-beam CP antennas, an important feature of the proposed antenna is that the AR bandwidth is completely included in the impedance bandwidth, that is, the overlap bandwidth of ∣ S 11 ∣ < − 10 dB and AR < 3 dB is 30.1%. Moreover, the stable omnidirectional conical-beam radiation patterns can be maintained within the whole operational bandwidth.

Low‐profile circularly polarised patch antenna with high gain and conical beam

A low-profile circularly polarised (CP) antenna with conical-beam radiation pattern is presented. The proposed antenna consists of a monopolar patch antenna fed by a probe in the centre and a ring-shaped array formed by eight modified parasitic patch elements. Two resonant modes of the monopolar patch which connects to a ground plane by a set of conductive shorting vias are utilised to achieve wide impedance bandwidth. A CP conical-beam radiation pattern is formed by loading the designed array. Loop current and slot resonant mode are employed to discuss the operating principle. A parametric study is carried out for the detailed design concept illustration. To verify the design, a prototype has been fabricated and measured, which shows a low profile of 0.059 λ 0 , a maximum gain of 7.45 dBic, a 10-dB impedance bandwidth of 23.1%, a 3-dB axial ratio bandwidth of 9.6% and a good conical-beam radiation pattern.

Generation of Circularly Polarized Conical Beam Pattern Using Torus Knot Antenna

A wideband circularly polarized antenna with a conical beam radiation pattern is presented. It consists of a torus knot as a radiator and a feeding probe to excite it. The proposed feeding mechanism is simple and does not use power divider network to generate circular polarization (CP). Characteristic mode analysis of a knot shows that a particular kind of knot, with a suitable excitation, can radiate omnidirectional beam with CP. To validate the design, a prototype of torus knot antenna is realized using additive manufacturing technology. The return loss, radiation pattern, and axial ratio (AR) are measured. A parametric study is carried out to understand the effect of various geometric parameters on the performance of the antenna. The fabricated torus knot antenna has a usable bandwidth of 51.8% and the measured AR bandwidth is 66%.

A Wideband Low Cost and Optically Transparent Water Patch Antenna With Omnidirectional Conical Beam Radiation Patterns

A novel kind of optically transparent, low cost and wideband water patch antenna is demonstrated and analyzed. A significant feature of the proposed linearly polarized antenna is that both the patch and the ground plane are made of water. Thus, the whole structure becomes optically transparent except the small central feeding probe. The main radiators are made of water, which is available everywhere, low in cost and easy to be fabricated compared with other transparent materials. Results show that a wide impedance bandwidth of 35% for ${\vert } {\text {S}}_{{{11}}} {\vert } dB, a gain up to 4 dBi and symmetric omnidirectional conical beam radiation patterns with small cross-polarizations can be obtained. Due to the low cost and remarkable radiation performances, this novel transparent patch antenna is believed to have many promising applications in the future transparent electronics designs and flexible electronics.

Compact-Size Low-Profile Wideband Circularly Polarized Omnidirectional Patch Antenna With Reconfigurable Polarizations

A compact-size low-profile wideband circularly polarized (CP) omnidirectional antenna with reconfigurable polarizations is presented in this communication. This design is based on a low-profile omnidirectional CP antenna which consists of a vertically polarized microstrip patch antenna working in $\text{TM}_{01}/\text{TM}_{02}$ modes and sequentially bended slots etched on the ground plane for radiating horizontally polarized electric field. The combined radiation from both the microstrip patch and the slots leads to a CP omnidirectional radiation pattern. The polarization reconfigurability is realized by introducing PIN diodes on the slots. By electronically controlling the states of the PIN diodes, the effective orientation of the slots on ground plane can be changed dynamically and the polarization of antenna can be altered between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The proposed antenna exhibits a wide-operational bandwidth of 19.8% (2.09–2.55 GHz) with both axial ratio below 3 dB and return loss above 10 dB when radiates either LHCP or RHCP waves. Experimental results show good agreement with the simulation results. The present design has a compact size, a thickness of only $0.024\lambda$ and exhibits stable CP omnidirectional conical-beam radiation patterns within the entire operating frequency band with good circular polarization.

Polarization Reconfigurable Wheel-Shaped Antenna With Conical-Beam Radiation Pattern

This paper introduces a polarization reconfigurable wheel-shaped antenna with wide bandwidth and conical-beam radiation pattern. A wideband circular-monopolar patch surrounded by eight reconfigurable coupling loop stubs can generate conical-beam radiation patterns with different polarizations. This polarization reconfigurable characteristic is realized by controlling PIN diodes on the coupling loop stubs. The center-fed circular patch operates with the vertically-polarized conical-beam radiation and the coupling loop stubs radiate the horizontally-polarized wave propagation. With choosing proper magnitudes and phase differences between the two orthogonal radiations from the monopolar patch and the loop stubs, a circularly-polarized conical-beam radiation can be obtained. In addition, the presence of a back reflector yields a wide axial ratio bandwidth, enhances the front-to-back ratio of the radiation pattern, and avoids EM interferences between DC biasing lines and the antenna. This proposed antenna can generate three types of polarizations with the conical-beam radiation pattern including vertical polarization, left-handed circular polarization, and right-handed circular polarization by controlling the PIN diodes. Measured impedance and axial ratio bandwidths are 28.6% (3.45 to 4.6 GHz) and 15.4% (3.6 to 4.2 GHz), respectively, for the two CP modes. The maximum CP gain is 4.4 dBic. Furthermore, a dual-band operation (3.35 to 3.44 GHz and 4.5 to 4.75 GHz) can be observed for the LP mode. The antenna can operate at the downlink of standard C band (3.625 to 4.2 GHz) for geostationary satellite communication.

Circularly Polarized Conical-Beam Antenna With Wide Bandwidth and Low Profile

This work introduces a circularly polarized (CP) conical-beam antenna with low profile and wide impedance & axial ratio (AR) bandwidths. The antenna structure simply consists of a wideband monopolar patch antenna and eight parasitic loop stubs for generating vertically polarized electric field Eθ and horizontally polarized field Eφ, respectively. The proposed antenna is low profile but wideband because of merging the TM01 and TM02 modes at around the center frequency. In order to obtain the wideband CP radiation, the eight parasitic loop stubs are printed and placed sequentially along the radiating edge of the patch. With the resultant radiations from both the patch antenna and the loop stubs, the CP conical-beam radiation pattern can be obtained. In addition, a parametric study of the shorting vias effect, number of loop stub elements, and loop widths are demonstrated how to design this wideband CP antenna. The antenna exhibits the wide impedance bandwidth of 28% from 4.9 to 6.5 GHz (for the reflection coefficient ≤ -10 dB) and the 3-dB AR bandwidth of 14.4% from 5.8 to 6.7 GHz. The thickness of this antenna is only 0.06λ in terms of the free-space wavelength at its lowest operation frequency. Stable omni-directional conical-beam radiation patterns are observed over the operating bandwidth with the peak gain of 4.9 dBic. The antenna can cover the uplink of standard C band (5.85 to 6.425 GHz) for satellite communication.

Wideband modified L-probe fed circularly polarized patch antenna with conical beam radiation pattern

A wideband circularly polarized patch antenna with conical beam radiation pattern is presented. The antenna structure is composed of a circular patch, two modified L-shaped probes, and a wideband 90° hybrid feed network. The higher mode of TM21 mode is excited on the circular patch to produce the conical beam radiation pattern. The proposed antenna has a measured common operating bandwidth with 10-dB return loss, 3-dB axial ratio bandwidth, and good conical beam radiation pattern is about 20.1% with respect to the center frequency of 2.9 GHz from 2.6 to 3.2 GHz. The average gain of the proposed antenna is about 6.5 dBi over the operating band. Good agreement is observed between the simulated and measured results.

CONICAL BEAM WINDMILL-SHAPED ARRAY ANTENNA DESIGN BASED ON QUARTER-MODE SUBSTRATE INTEGRATED WAVEGUIDE

This paper presents a compact conical beam antenna based on quarter-mode substrate integrated waveguide (QMSIW). The antenna array is consisted of six isosceles right-angled triangle metallic patch printed on the upper side of the substrate in a windmill-shape and diagonal periodic metallic via holes drilled along the hypotenuse of the triangle patch. The planer structure exhibits conical beam radiation. The typical radiation is obtained at 5.2GHz with conical beam radiation pattern. The measured gain is about 5.36dBi and the radiation e-ciency is around 50%.

Design of a dual‐mode annular ring antenna with a coupling feed

AbstractA dual‐mode annular ring antenna for both global positioning system (GPS) and satellite digital multimedia broadcasting (S‐DMB) is designed. The proposed antenna consists of a coupling feed line and four slots on an annular ring patch. A gap between the feed line and the annular ring patch is used for an input impedance matching; the slots are used for adjusting the resonant frequency of the TM21 mode at the DMB frequency. The antenna was fabricated and measured. The antenna resonates at the GPS and DMB frequencies with suitable bandwidths. It has a broadside radiation pattern in the GPS band and a conical beam radiation pattern in the DMB band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 3011–3013, 2009; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24796

커플링 급전을 이용한 이중 모드 Annular Ring 안테나 설계

본 논문에서는 GPS와 위성 DMB에 사용할 수 있는 이중 모드 annular ring 패치 안테나를 제안하였다. 제안된 안테나는 커플링 급전과 annular ring 패치의 네 개의 슬롯을 특징으로 한다. 급전 선로와 패치 사이의 간격은 입력 임피던스를 조절하는 역할을 하고, 패치의 슬롯의 길이는 DMB 주파수에 해당하는 <TEX>$TM_{21}$</TEX> 모드의 공진 주파수를 조절하는 역할을 한다. 제안된 안테나를 제작 및 측정을 하였다. 제작된 안테나는 GPS와 DMB 주파수에서 만족할만한 대역폭을 가지고 공진을 일으키며, GPS 대역에서는 broadside 방사 패턴을 가지고 DCS 대역에서는 코니컬 빔 방사 패턴을 가진다. A dual-mode annular ring antenna for both global positioning system(GPS) and satellite digital multimedia broad-casting(DMB) is designed. The proposed antenna consists of a coupling feed line and four slots on the annular ring patch. The gap between the feed line and the annular ring patch is used for an input impedance matching, and the slot length is used for adjusting the resonant frequency of the <TEX>$TM_{21}$</TEX> mode at the DMB frequency. The antenna was fabricated and measured. The experimental results show that the antenna resonants at the GPS and DMB frequencies with suitable bandwidths, and had a broadside radiation pattern at the GPS band and a conical beam radiation pattern at the DMB band.

New analytical model for the radiation pattern of a TM 02 mode circular patch antenna

A new analytical model is proposed for the conical beam radiation pattern of the TM 02 -mode circular patch antenna. It is based on a correct physical description of the radiation mechanism at low-elevation angles, and yields better agreement with measurement than available models.