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Electrically small Huygens dipole antennas are reported that are low profile, broadside radiating, have high radiation efficiencies, and are either linear (LP) or circularly (CP) polarized. The Huygens behavior, i.e., a high front-to-back ratio with a cardioid-like pattern, is realized by exciting two (LP) or two pairs (CP) of complementary electric and magnetic dipole radiators, simultaneously having...
In this paper, a miniaturized wideband dual-polarized antenna loaded with parasitic loops and straight dipoles has been proposed for 2G/3G/4G base-station applications. Firstly, by loading four parasitic loops to the corners of regular crossed loop dipoles, a miniaturized structure and enhanced impedance bandwidth can be obtained. Then, based on the miniaturized structure, two straight dipoles are...
This paper presents design of a varactor-loaded frequency-tunable ring microstrip antenna with reduced bias circuits. Two varactor diodes are mounted on square ring patch element fed by an L-probe to realize a frequency-tunable microstrip antenna. An L-shaped feeding probe is used to realize impedance matching of the ring microstrip antenna. Resonant frequency of the proposed antenna can be tuned...
This paper proposes small CRPA arrays with high-dielectric ceramic superstrates for dual-band operation. Each array element consists of inner and outer microstrip rings printed on a high-dielectric substrate, and a hybrid chip coupler is used for quadrature excitation to achieve circular polarization. The superstrates with high relative permittivity are designed to have a cylindrical shape and are...
This paper presents a design of the universal reader antenna applied for the radio frequency identification (RFID) system with the operating frequency from 840 MHz to 960 MHz. The antenna structure consists of a rectangular loop and a rectangular feeding patch which are the important elements to produce the circular polarization. The total size of the reader antenna is 120 mm ×120 mm fabricated on...
Several compact multiband antennas used for wireless communications will be presented in this lecture. Most of antennas are based on the slot and coplanar structures. The first antenna is a compact broadband printed slot antenna integrating with filters for band notching. The filters including I-shaped and inverse L-shaped narrow slits and L-shaped conductor strip are integrated in the proposed antenna...
A kind of low sidelobe and high gain microstrip antenna array with 32×8 units operating in the X-band is designed, which achieves the gain of 28 dBi and the sidelobe level of −25 dB at 9.37 GHz. The Chebeshev distribution is used in designing the current distribution on the surface of this antenna, which achieves a width of main lobe of 5° in E-plane and a main lobe width of 10° in H-plane. The amplitude...
A novel satellite base station configuration based on the Distributed Array Antenna (DAA) technique is studied to eliminate mechanical satellite tracking equipment. A DAA controller integrates all antennas so each antenna's aperture can be downsized and its transmitting power reduced while realizing the required characteristics. This paper revealed the maximum gain achievable with the DAA base station.
In this paper, the bandwidth enlargement method of the conventional λ/4 monopole antenna on finite ground plane is investigated for utilization in IFF (Identification friend or foe) of the secondary radar the operating frequency 1.03–1.09 GHz. For the initial study, we have proposed the structure of the resonant holes on the surface of a sector of metallic cylinders covering such the monopole that...
In order to improve the gain of the array antenna element in the W-band and reduce its horizontal dimension, The directional radiation antenna loading dielectric sheet based on SIW technology is proposed. The antenna uses a conventional micro strip line to feed the gradient open micro strip line. Then the gradient open micros trip line feeds the SIW. Finally, the dielectric sheet loaded in SIW will...
An 8×8 slot array with high-efficiency and corporate-fed single layer by ridge gap waveguide at 60-GHz is introduced in this paper. The manufactured antenna depicts more than 19.6% bandwidth with input reflection coefficient better than −10 dB and the aperture efficiency higher than 70% with around 26 dBi realized gain between 58 and 66 GHz.
This paper proposes the design of high gain and broadband waveguide antenna which is fed by using a microstrip antenna is at 2.33 to 5.24 GHz. A feeding network is broadband microstrip antenna with the flower-shaped combined with the rectangular waveguide antenna to improve the directive gain. The proposed antenna can be fabricated on conventional low-cost materials by using FR4 and aluminum plate...
In this paper, a 60 GHz CMOS on-chip dipole antenna with loss-reduced silicon substrate, which had been proposed and simulated by the authors, was measured and gain improvement of approximately 9 dB was obtained. In the antenna, rectangular region with 500 μm × 1000 μm around the dipole is irradiated by proton and conductivity is reduced from 10 S/m (10 Ω cm) to 0.1 S/m (1 kΩ cm). Antenna gain of...
In order to reduce the minimum antenna measurement distance, the aperture reduction is needed. While the aperture reduction will cause the gain of the antenna reduced. The method of loading the elongated dielectric rod on the rectangular waveguide can remarkably improve the gain of the antenna without increasing the antenna aperture. A simulation study was carried out on the antenna with a dielectric...
The scientific payload GeReLEO-SMART will be launched on the German geostationary satellite “Heinrich-Hertz”. It should prove the technology readiness of a data receive antenna for low earth orbit (LEO) satellites and work as a data relay. The receiving antenna works in the Ka-Band and is composed of a four layer soft substrate PCB with integrated preselector band pass filter and low noise amplifier...
This paper proposes a new low-profile high-gain wideband gradient refractive index (GRIN) lens fed by a magnetic-electric (ME) dipole antenna. As a constituent part of this lens, a novel sub-wavelength nonresonant metamaterial unit cell composed of 3-layer substrates is also proposed. By applying Rogers 5880 and air as the top and bottom layers, high and low refractive indexes can be achieved for...
This paper presents the application of metamaterial structure for improving the gain of antenna to extend the reading distance of UHF RFID reader without any modifying of the original reader. The proposed structure of metamaterial is designed on the theory of Spilt Ring Resonator (SRR), which located in front of such the RFID reader, while the back side of reader is blocked with a metallic sheet as...
This paper proposes a small CRPA array with frequency-insensitive properties. The array consists of seven elements, and each element is composed of upper and lower circular loops that are designed to resonate at 1.575 GHz and 1.227 GHz, respectively. The lower loop is fed by the hybrid chip coupler, and the upper loop is electromagnetically coupled for a frequency-insensitive feeding mechanism. Due...
The spiral termination helical antenna is proposed in this paper. To reduce axial length, the number of helical turns is selected to be two turns and the pitch angle is selected to be 2.5°. The axial length of the proposed antenna is 0.15 λ0 (46 mm). It is reduced to 80% of conventional low-profile helical antenna. The gain of proposed antenna is 9.6 dB and 3 dB axial ratio bandwidth is 10%.
On the reflectarray using ring-type resonator elements, a high efficiency design method was adopted and its results were confirmed at the design frequency. In this paper, in addition to the conventional high efficiency design method, a reflectarray was designed and measured by considering the broadband conditions. As a result, the aperture efficiency of the fabricated reflectarray was more than 65%...
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