Shared Aperture Antenna Array Research Articles

Low Profile Dual-Band Shared Aperture Array for Vehicle-to-Vehicle Communication

In this paper, we present a non-standalone dual-band shared aperture antenna array that operates at both the current Dedicated Short Range Communications (DSRC) band (viz. 5.9 GHz) and the future 5G millimeter-wave (mm-wave) band (viz. 28 GHz) allocated for vehicle-to-vehicle (V2V) communications. The design consists of a 2 $\times $ 2 differentially fed patch array operating at 5.9 GHz, co-printed with a 1 $\times $ 2 series fed array operating at 28 GHz on a single layer substrate. In particular, the shared aperture array operates from 5.84-5.94 GHz (DSRC band) with a 100 MHz impedance bandwidth and from 27.75 - 28.47 GHz (5G mm-wave band) with a 720 MHz impedance bandwidth. Gain improvement of ~1.44 dB at 28 GHz is observed as a result of the higher order modes generated by the 5.9 GHz array. The shared aperture array was fabricated and measured showing a gain of ~9.97 dBi at 5.9 GHz and ~12.3 dBi at 28 GHz. The ports of the array are highly isolated with measured isolation >55 dB at the DSRC band and >33 dB at the 5G mm-wave band.

Hybrid‐fed shared aperture antenna array for X/K‐band airborne synthetic aperture radar applications

The design of X/K-band shared aperture antenna (SAA) single-linear polarized K-band, dual-polarized (linear/circular) X-band 36-elements (6×6) planar array antenna with high gain, and low cost for airborne synthetic aperture radar systems is presented. To reduce the complexity and size of the feed networks, the concept of series-feed centre-fed open stub array with Chebyshev amplitude distribution of −25 dB side-lobe levels (SLL) are employed for K-band design. Two typical frequencies, X-band and K-band of 9.65 and 21 GHz, are chosen (frequency ratio of 1:2.176) in this proposed SAA design on a single-layer printed circuit board. For K-band design, SLL can be controlled by Chebyshev distribution. The amplitude is controlled by the width of the individual patch in the linear array with left and right symmetries. A 50-Ω microstrip line with 0.7λ spacing is used in between the patches for the ±25° scan angle requirement. The measured results are consistent with the simulations and provide a matching impedance bandwidth of 10.36/1.45% at X/K-bands, respectively. The array also has a high aperture efficiency of more than 85%, SLL of (X/K-bands: −18.9/−25 dB), and gain of (X/K-bands: 24.2/17.4 dBi).

Compact Dual-Frequency Antenna Array With Large Frequency Ratio

A dual-fed dual-frequency shared-aperture antenna array with a large frequency ratio is investigated. Its unit cell consists of a microwave ground-surrounded patch antenna and a millimeter-wave substrate-integrated 2×2 slot antenna subarray. The former is excited in the fundamental TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> mode, whereas the slot elements are excited in their fundamental mode. Based on the dual-frequency antenna unit, a dual-frequency antenna array is designed. To demonstrate the idea, a prototype that consists of a C-band 2×2 patch antenna array and a Ka-band 8×8 slot antenna array was designed, fabricated, and tested. Its matching and radiation characteristics are studied for both bands. Reasonable agreement between the measured and simulated results is observed. Excellent measured intraband isolations of over 32 dB are obtained.

Helical Torsion Coaxial Cable for Dual-Band Shared-Aperture Antenna Array Decoupling

Direct connection between coaxial cables and antenna radiators is one of the most popular and simplest approaches for antenna excitation. In dual-band shared-aperture antenna arrays that operate in higher and lower frequency bands, feeding coaxial cables of the higher band antenna array will inevitably introduce electromagnetic coupling in the lower band antenna arrays. The cross-band coupling will further lead to radiation pattern distortion, gain decrease, and impedance mismatching in the lower band antennas. Instead of using conventional straight coaxial cable feedings, this article proposes to decouple the unwanted cross-band coupling with a novel helical torsion coaxial cable design. The helical torsion feeding (HTF) coaxial cables are investigated from equivalent circuit analysis and full-wave simulation. The analysis results demonstrate that the HTF coaxial cable possesses open-circuit characteristic in the operation band of the lower band antenna. Through this design, the cross-band coupling is effectively suppressed at 0.69 GHz. The effectiveness of the approach is then demonstrated in a dual-band shared-aperture antenna array. Both the simulated and measured results validate the proposed design. The proposed decoupling method will find applications in compact multiband 5G MIMO antenna array developments.

A Microwave/Millimeter Wave Dual-Band Shared Aperture Patch Antenna Array

This paper describes the design of microwave/millimeter wave dual-band patch antenna array with shared aperture. The antenna array is designed of stack structure of three printed circuit boards. The Ka-band patches are fed directly with microstrip lines of the Ka-band power divider network and the E-band patches are coupling fed by the E-band power divider network through slots cut in the antenna ground. An antenna unit is studied, fabricated and measured firstly to verify the feasibility of the shared aperture structure. Finally, a shared aperture antenna array consists of a $2\times 4$ Ka-band array and an $8\times 16$ E-band array is designed based on the antenna unit. The E-band and the Ka-band feeding network are carefully designed to reduce the reflections, and the Ka-band feeding network combines series feed and parallel feed in order to save space. The shared aperture antenna array is fabricated and measured, and the results are presented. In order to measure the E-band array, the main port of the E-band power divider is connected to a standard WR12 waveguide through an antipodal fin-line waveguide to microstrip transition.

A Dual-Band Shared Aperture Antenna Array in Ku/Ka-Bands for Beam Scanning Applications

A dual-band shared aperture antenna array for phased array system operated in Ku/Ka-bands is proposed in this paper. By judiciously designing the geometrical structure and parameters, compact and integrated antenna elements are proposed to achieve the maximum scanning angle without the grating lobes phenomenon. The patch-dipole antenna elements operating in Ku-band and microstrip patch antenna elements operating in Ka-band are designed and fabricated utilizing a four-layer lamination substrate. Metal shielding vias are introduced to suppress the coupling between the antenna elements operating in different bands, meanwhile, defected ground structure is introduced to eliminate the scan blindness effect and improve the beam scanning range effectively. The proposed antenna array has 208 Ku-band elements and 832 Ka-band elements distributed in the shared aperture with a diameter of 200 mm. Measured results show that the proposed antenna array has a broad impedance bandwidth of 10.7% in Ku-band and 9.1% in Ka-band, meanwhile it has a relatively wide scanning angle ranging from -45° to +45° with low gain decrease and side lobe level. The proposed phased array antenna has potential application in a radar system, mobile communication system, and so on.

Design of L/X‐band shared aperture antenna array for SAR application

ABSTRACTDesign of a dual‐wideband dual‐polarized planar shared aperture microstrip antenna array is proposed in this article. Differential feeding method is used to enhance the isolation between polarizations of the antenna in both bands.Corporate feed network is used for good radiation pattern results. Further, the coupling between the feed networks the two orthogonal polarizations is minimized. This is achieved using the antenna elements to separate the feed networks for orthogonal polarizations. To verify the antenna design, a prototype is fabricated and measured. For VSWR, the antenna can cover from 1.07 to 1.24 GHz (14.7%) and from 8.3 to10.3 GHz (21.5%), respectively. The measured isolation between bands is higher than 30 dB and the isolation between polarizations is higher than 22.5 and 29.6 dB in L‐ and X‐band, respectively. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2197–2204, 2015