Dual-Polarized 6–18-GHz Antenna Array With Low-Profile Inverted BoR Elements

Abstract

This article investigates a dielectric-loaded Vivaldi-type antenna array that is formed inside a plastic block. It utilizes the inverted body-of-revolution (BoR) structure, where cone-shaped cavities are formed in a dielectric material and metalized from the inside. The metalized cavities form an array of inverted BoR elements that are fed by a single printed circuit board. In contrast to previous work, this paper uses a solid, shaped plastic block instead of foam as a dielectric material and exploits its considerably higher permittivity to reduce the height of the elements. The reduced profile provides an excellent polarization purity in the class of tapered slotline (TSL) antennas while a 3:1 bandwidth is maintained with an active reflection coefficient (ARC) ≤ −10 dB. The shaping of the dielectric block decreases the scan loss of the array and prevents detrimental surface waves. The proposed array can steer the beam up to ±50 • in all planes without exceeding −10 dB ARC. The proposed dielectric loading may be applied also to other antenna types, such as conventional BoR antennas. The excellent electrical performance and manufacturability of the array are confirmed by fabricating and measuring a prototype. antenna array, body-of-revolution, flared-notch, low-profile, Vivaldi, wideband INDEX TERMS

A Fully Integrated Filtering Vivaldi Antenna With High Selectivity and Wide Out-of-Band Suppression

“…The measurement results in terms of S11 and realized Ref. Table 2 compares the proposed filtering antenna structure with previously reported Vivaldi-based filtennas [8], [25], [27], [29]. The proposed multi-functional filtenna offers low insertion loss, wide out-of-band suppression (2-24GHz), adjustable fractional bandwidth (from approximately 10% up to the Vivaldi entire bandwidth), high band-selectivity with control over both higher and lower filter cut-off frequencies (f l , f h ) across the wide operational Vivaldi range/bandwidth (6:1), and full integration while maintaining the original base antenna size.…”

“…In [27], a highly integrated filtering Vivaldi antenna utilizes slotline surface plasmon polaritons, reported in [28], to filter out the frequencies above 27GHz with outof-band gain suppression of about 14dB. In [29], the bandpass filtering Vivaldi antenna array incorporates a low-pass filter, realized by periodically slotline's corrugation, and a high-pass filter realized by surrounding the antenna by a waveguide. Its fractional passband bandwidth is 88% (1.2-3.1GHz) with upper band gain suppression of ≥20dB up to 6GHz.…”

“…The ability to control the lower edge frequency of the filtering antenna has not been addressed in references [10], [27] and the authors have used the lower cutoff antenna frequency. Moreover, in [29], due to incorporating a waveguide to control the lower edge frequency, the adjustment becomes complicated. Furthermore, operational bandwidth tuning has not been addressed in the literature.…”