Wide-beam Microstrip Research Articles

Periodic Asymmetric Trapezoidal Perturbation Microstrip Antenna for Millimeter-Wave Automotive Radar Sensors

This article presents a new design and experimental verification of a broadband wide-beam microstrip array antenna for short-range automotive radar sensors. The antenna is designed based on a pure microstrip transmission line, by inserting short inverted trapezoidal stubs alternately on both sides of the microstrip line periodically to generate a trapezoid-cascaded electric field, which enables the proposed antenna to radiate effectively. Therefore, the proposed antenna has the advantage of a simple structure. The antenna has a larger effective radiation aperture, which leads to a smaller quality factor, so the antenna has a broad bandwidth of 13% (74.02–85.08 GHz), completely covering 76–81 GHz automotive radar frequency band. The peak gain is up to 10.4 dBi. Based on the proposed antenna, a three transmitting antennas and four receiving antennas (3T4R) multiple-input-multiple-output (MIMO) radar antenna array is designed. To reduce the influence of strong surface waves on the radiation pattern, a design conception of a dummy array with an absorbing load is introduced. The array antenna of each transmitting (TX)/receiving (RX) channel can achieve a wide half-power beamwidth (HPBW) of 120° in the azimuth plane. Besides, the MIMO array exhibits good consistency, with the absolute amplitude error of TX-RX channels less than 3 dB and the phase error less than 20° in the azimuth plane.

Design of a Wide-Beam Microstrip Array Antenna for Automotive Radar Application

In this paper, a novel wide-beam microstrip patch array antenna is proposed for automotive radar applications. Different from the regular wide-beam antenna, which is designed to achieve the wide-beam unit radiation performance, the proposed array antenna introduces the coupled-mode technology of the microstrip antenna to design an inclined unit radiation beam. The array elements are arranged alternately and in opposite phases so that the unit radiation beams alternately point to two sides of the array. The wide-beam feature and the high gain performance are realized simultaneously by the array characteristics. The excellent beamwidth and antenna gain performance enable enormous application potential in automotive radar. An 8-unit prototype working at 24 GHz is designed and fabricated for automotive radar applications. Measured results show that the special design scheme extends the horizontal-plane half-power beamwidth (HPBW) to 140°, and the maximum antenna gain is over 10.5 dBi.

79-GHz Wide-Beam Microstrip Patch Antenna and Antenna Array for Millimeter-Wave Applications

A wide-beam microstrip patch antenna and antenna array ranging from 77 to 81 GHz are presented in this study for millimeter-wave applications. A substrate-integrated-waveguide probe-fed patch was developed. For beamwidth enhancement, two I-shaped parasitic elements were placed next to the main patch to establish a three-element subarray. The current directions of the parasitic elements were opposite to that of the main patch, leading to beamwidth enhancement in the E -plane radiation pattern. The proposed I-shaped parasitic element has the advantages of coplanar structure, compact size, and easy adjustment of the induced current. An array-factor method was employed to analyze the effect of the parasitic elements on the beamwidth of the main patch. Three amplitude distributions of the subarray were compared. The distribution of -0.1:1:-0.1 was proved to present the most beamwidth, which can be realized easily by the proposed I-shaped parasitic elements. To achieve both wide beamwidth and high gain, a 1 × 8 patch antenna array with the I-shaped parasitic elements was proposed. The measured results showed that the design can offer a gain of 10.74 dBi and a wide beamwidth of 138° at 79 GHz.

A Wide-Angle E-Plane Scanning Linear Array Antenna With Wide Beam Elements

In order to improve the wide-angle scanning performance of the phased array antennas, a wide-beam microstrip antenna with metal walls is proposed in this letter. The beamwidth of the antenna is broadened by the horizontal current on the radiating patch and the vertical current on the metal walls. The half-power beamwidth of the E- and H-planes is 221° and 168° at 4.0 GHz. Furthermore, the wide-beam antenna element is employed in a nine-element E-plane linear array antenna. The main beam of the E-plane scanning linear array antenna can scan from −70° to +70° in the frequency band from 3.7 to 4.3 GHz with a gain fluctuation less than 2.7 dB and variation in maximum sidelobe level less than −5.8 dB. The E-plane scanning linear array antenna with nine elements is fabricated and tested. The measured results achieve a good agreement with the simulated results.

Compact Wide-Beam Circularly-Polarized Microstrip Antenna With a Parasitic Ring for CNSS Application

A compact single-feed circularly-polarized (CP) wide beam microstrip antenna is proposed for CNSS application. The antenna is designed with a double-layer structure, comprising a circular patch with two rectangular stubs along the diameter direction and a parasitic ring right above it. The resonance frequency and the CP characteristics are mainly controlled by the circular patch and the rectangular stubs, respectively. The vertical HPBW (half power beam width) could be widened by the parasitic ring. Experimental results show that the measured vertical HPBW is approximately 140° and the measured out-of-roundness for the horizontal radiation pattern is only 1.1 dB. Besides, it could maintain good low-profile characteristics.

A WAVEGUIDE-FED PYRAMID-SHAPED DIELECTRIC ROD ANTENNA WITH SIZE REDUCTION AND HIGH GAIN FOR WIDEBAND APPLICATIONS

This article proposes a new design of wideband wide beam microstrip like antenna (MLA) in X-band (8{12GHz) overcoming the limitations of conventional MLA design. The waveguide is fllled with a dielectric material, which is shaped beyond the waveguide aperture as a pyramidal structure. This helps in achieving the size reduction of the waveguide and matching of aperture admittance over the complete operational band. Also a vertical electric dipole feed design is proposed to excite MLA and match the source and load admittances. The input re∞ection coe-cient observed over the complete band is better than i10dB. The measured gain and cross polarized levels of antenna achieved are better than 3dBi and i18dB across the bandwidth, respectively. The measured and simulated results are in good agreement.

Squashed Single Feed Circularly Polarised Micro strip Antenna for Navigation Applications

A squashed single-feed circularly-polarized (CP) wide beam microstrip antenna is projected for CNSS application. The antenna is intended by a double-layer arrangement, comprise a round space with two rectangular stubs the length of the width route and a sponging ring accurate more than it. To gather the uplink and downlink band of the scheme, a dual-band circularly polarized antenna should be encouraged and applied. In the meantime, due to the little number of CNSS satellites, the enormous gain of terminal antenna for small altitude is necessary. The third generation message scheme has been formally implement in our saleable. With the increasing difficulty of the scheme, it is straight away need to solve the multipath signal degradation and reduce the numeral, the cost and the site of antenna. For immediately gathering these supplies, the composite dual-polarized base location transmitter has been the prospect trend. The antenna is considered with a doublelayer arrangement, comprise a round patch with two rectangular stubs along the distance route and a parasitic ring right above it. The resonance frequency and the CP character are mostly prohibited by the round patch and the rectangular stubs, correspondingly. The perpendicular HPBW could be widening by the parasitic ring. New results show that the deliberate vertical HPBW is around 140 and the deliberate out-of-roundness for the horizontal radiation pattern is only 1.1 dB. In addition, it could uphold good inconspicuous character.

A Broad Band and Wide Beam Microstrip Antenna Array

A novel broad band and wide beam microstrip helical antenna is proposed based on the modification of traditional helical antennas. Through selecting the appropriate operating mode between the axial mode and the normal mode, this new antenna can broad both the beamwidth and the bandwidth. To improve the gain of the antenna, An antenna array with 1*16 elements is designed and fabricated. Meanwhile, cavity-loaded feeding network is utilized for probe station measurement. The simulated impedance and radiation pattern are studied. The proposed antenna shows a wide impedance bandwidth from 7.6GHz to 9.6GHz for |S11|<-10dB, with wide 3dB beamwidth of E-plane about 1200, respectively.

OPTIMIZATION OF THREE-DIMENTIONAL (3-D) GROUND STRUCTURE FOR IMPROVED CIRCULARLY POLARIZED MICROSTRIP ANTENNA BEAMWIDTH

A novel circularly polarised (CP), single-fed widebeam microstrip antenna is presented. The antenna consists of a corner- truncated square patch and a three dimensional circular ground structure. Simulated and measured results show that, owing to the ground structure, the 3dB beamwidth of the CP radiation can reach more than 165 - , which is about 85 - greater than that of a corresponding regular microstrip antenna. It is also shown that experimental results were in good agreement with the simulated performance. Details of the proposed 3-D circular ground structure are described, and the efiects of various dimensions of the proposed ground structure on the beamwidth enhancement of CP radiation are studied.

A widebeam microstrip antenna for intelligent transport system application

AbstractA wide‐beam and middle‐gain microstrip antenna for the intelligent transport system (ITS) is demonstrated experimentally and numerically. The results show that a −3‐dB beam width of 105°, a middle gain of 10 dBi, and a bandwidth of about 12% for VSWR less than 2:1 are obtained. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 200–202, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20092