Design and Experimental Validation of Multifunction Antenna With Direct Modulation for Radar and Communication

Abstract

A multifunction antenna system providing a radar function and a communication function simultaneously is proposed. The system is composed of a horn antenna whose feeding waveguide is loaded with slots. The horn radiation is used for the main radar function. The slotted waveguide radiation is controlled independently from the horn radiation to perform a direct binary phase shift keying (BPSK) communication provided that each radiating slot is equipped with a simple switching mechanism. Then, the antenna system provides two different functions using orthogonal polarizations and directions. Measured results show 9.1 dB and 32 dB isolation between the two functions at the working frequency. In addition, the proposed system can be integrated with the existing radars which use horns by replacing only the feeding waveguide.

Frequency‐Controlled Focusing Using Achromatic Metasurface

“…[22] Although some geometric-phase metasurfaces can realize parallel phase profiles as well as dispersion profile manipulation, these devices suffer from poor broad bandwidth performance. [23][24][25][26] Focus-scanning technology realized by an individual metadevice has important applications, such as multiple modes of phased-array radar scanning, [27] synthetic aperture radar (SAR) imaging, [28][29][30][31] sensing, and communications. [32,33] However, the reported focusing meta-devices [34,35] usually work only at a target frequency or a particular range of frequencies; therefore, these cannot achieve a high broad bandwidth performance.…”

“…Focus‐scanning technology realized by an individual meta‐device has important applications, such as multiple modes of phased‐array radar scanning, [ 27 ] synthetic aperture radar (SAR) imaging, [ 28–31 ] sensing, and communications. [ 32,33 ] However, the reported focusing meta‐devices [ 34,35 ] usually work only at a target frequency or a particular range of frequencies; therefore, these cannot achieve a high broad bandwidth performance.…”

A Multifunction Antenna: Radar and QPSK Comms

“…Four slots are etched in the waveguide wall as shown in Figure 1. As explained in [1] [2], slots at same with identical x coordinates but with opposite y coordinates radiate out of phase. To obtain phase quadrature, we add a horizontal displacement corresponding to a quarter wavelength in the waveguide (λg/4).…”

“…In previous works [1] [2], the authors have developed a multifunction antenna using a horn (for the radar function) and a slotted waveguide (for the communication function) with a single source. In this way the comms radiation is in another direction with respect to the radar radiation but also has orthogonal polarization.…”

Optimal Polyphase Coded Signal Design

“…MPSO fails to deviate similar to PSO a small dip establishes at Doppler frequency of 0.4 and then rises again. Thus, polyphase sequence are designed using MPSO at varied length but its correlation property with sequence length 40 and 128 are only used to compare with existing technique [21]. Table 3 presents the four different polyphase sequences with arbitrary length 40 with mean auto correlation and cross-correlation of -26.37dB, and -25.35dB, thus providing an efficient polyphase sequence at identical length [20].…”