Dual-beam Radiation Pattern Research Articles

A Compact Low-Profile Antenna for Millimeter-Wave 5G Mobile Phones

This paper presents a very low profile and simple antenna design for dual beam and dual-band operation to be employed in future 5G mobile phones operating in the millimeter-wave bands of 26.75–30.31 and 35.83–41.22 GHz. The two distinct resonances at 28 and 38 GHz are achieved using a meta-material-based structure consisting of a closed-ring resonator (CRR) and a split-ring resonator (SRR) by co-centrically combining two planar hexagonal rings; i.e., an inner split-ring resonator (SRR) and an outer closed-ring resonator (CRR). The antenna has a high gain of 4.5 dBi. The antenna also exhibits a dual-beam radiation pattern in one of its planes. The overall antenna size is 6 × 8 mm2 and is manufactured using a low-cost PCB fabrication process. The antenna’s dual-beam operation, broadband characteristics, high gain, and low profile makes it a potential candidate for future millimeter-wave mobile phones, especially in applications where space diversity is required.

Systematic Design of a Holographic-Based Metasurface Reflector in the Sub-6 GHz Band

This letter presents a systematic method to regulating the response of an artificial impedance surface. The method is based on governing the dispersion diagram to control the depth of modulation so that a meaningful pattern of scatterers is obtained on the structure. The method is applied on a holographic-based large reflective metasurface to achieve a dual-beam radiation pattern with tilt angles of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm 45^{\circ }$</tex-math></inline-formula> in the azimuth plane at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$f=3.5$</tex-math></inline-formula> GHz. The structure is fabricated and the measured data concur with the simulation results.

A Dual-Beam Wideband Filtering Patch Antenna With Absorptive Band-Edge Radiation Nulls

A dual-beam filtering patch antenna with two absorptive band-edge radiation nulls and four reflective stopband radiation nulls is proposed. By loading a pair of T-shaped metallic strip underneath the radiating patch, a modified TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">22</sub> mode with TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> -like radiation pattern is obtained, which combines with the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> mode of the radiating patch, generating a wide operating band with symmetrical dual-beam radiation pattern. Two reflective radiation nulls are generated in both upper and lower stopbands for suppressing the out-of-band radiation. Through embedding two pairs of shorted small patch in the radiating patch, one absorptive radiation null combining with one absorptive resonant mode is produced at each band edge to absorb the band-edge incident energy, leading to a reduced reflection and sharp roll-off at both band edges, and therefore, the transceiver can be protected. With a total height of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.038~\lambda _{0}$ </tex-math></inline-formula> , a prototype is designed, fabricated, and measured, showing a −10 dB impedance bandwidth from 4.63 to 6.10 GHz with sharp band-edge roll-off, two radiation beams directed at ±40° with an in-band gain of 6.0 dBi, and high out-of-band suppression of over 15 dB.

Dual-Beam Periodic Leaky-Wave Antenna With Reduced Beam Squinting

In this letter, a dual-beam periodic leaky-wave antenna with a low beam-squinting character is presented. It has a simple and low-profile configuration, which consists of 15 slot radiating elements and one microstrip feedline. The slot radiating element creates nulls in the pattern at forward and backward endfire. By properly arranging the radiating elements with a small separation, the higher order spatial harmonics are suppressed. Fed by an air-substrate microstrip line working on the non-dispersion transverse electromagnetic (TEM) mode, the antenna has a moderate phase constant leading to a stable endfire array factor. By integrating the almost unchanged array factor and element pattern, the dual-beam radiation pattern with reduced beam squinting is obtained. To verify the design strategy, a prototype was designed, fabricated, and measured. Over the operating bandwidth from 2.7 to 3.2 GHz, the antenna exhibits a small measured beam squint of 6.8°.

An aperture-coupled linear microstrip leaky-wave antenna array with two-dimensional dual-beam scanning capability

This paper describes an X-band 4/spl times/1 aperture-coupled series-fed electronically steerable microstrip leaky-wave antenna (LWA) array design, which has dual-beam radiation pattern and two-dimensional (2-D) beam-scanning capability. The LWA array is operated in the first higher order mode and excited by center-fed aperture coupled for dual-beam operation. The varactor-tuned phase shifters are placed between the antenna elements. The measured half-power beamwidth of the H-plane and quasi-E-plane radiation patterns are less than 30/spl deg/. By tuning the reverse dc bias of the varactor diodes, the main beam can be scanned in azimuth plane from -13/spl deg/ to +13/spl deg/ off broadside. In the elevation plane, the beam-scanning angle is close to 20/spl deg/ as the operating frequency tuned from 11.58-12.5 GHz. Taking into account each phase-shifter insertion loss and phase progression, the measured results compared closely with the theoretical prediction. The proposed antenna array is suitable for wireless communication and collision warning radar systems.

An aperture-coupled linear leaky-wave antenna array with 2-D dual-beam scanning capability

An X-band four-element linear microstrip leaky-wae () antenna LWA array with a dual-beam radiation pattern and two- dimensional scanning capability is deeloped. The measured half- power beamwidths of the H-plane and quasi-E-plane radiation patterns are less than 308. By tuning the dc bias of thearactor phase shifter between the antenna elements, the main beam can be scanned in the azimuth plane from y138 to q138 off broadside. In the eleation plane, the beam-scanning angle is close to 208 as the operating frequency is tuned from 11.58 to 12.5 GHz. Q 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 25: 52)53, 2000.

A back-to-back dual-beam active microstrip leaky-wave antenna array with mode-switching capability

An X-band two-element back-to-back coupled-oscillatordri en spatial power-combining microstrip leaky-wa e antenna array is de eloped, which has a dual-beam radiation pattern and mode-switching capability. Two Gunn diode CPW oscillators are placed on the back side of the substrate, each dri ing two back-to-back microstrip leaky-wa e antenna pairs in opposite directions for dual-beam operation. This acti e antenna array is able to produce sum and difference patterns between the in-phase and 1808 out-of-phase mode by controlling the bias oltages of the Gunn diodes. Q 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 24: 195]197, 2000.

Back-Face Only Electrical Connections of Thickness Mode Piezoelectric Transducers

The radiation patterns of disk transducers connected in a recently reported novel manner by Laughlin, Drews, and Wilson is studied. In this connection, the back-face plating of a transducer is divided into two electrodes which constitute the only transducer-to- transceiver connection, and a dual-beam radiation pattern resulted. However, we found that repolarizing one half of the transducer re- stored a single beam pattern. This method of connection and regionally repolarizing the piezoelectric transducer appears highly advantageous for use in fabrication of both miniature transducers and various trans- ducer arrays (e.g., linear, annular, and matrix).