Realization of Low Profile Leaky Wave Antennas Using the Bending Technique for Frequency Scanning and Sensor Applications

Abstract

This paper proposes an efficient transmission line modulation by using the bending technique to realize low profile leaky wave antennas in the Ku-band for frequency scanning and sensor applications. The paper focuses mainly on the bending effects of the transmission line in terms of the sharpness of edges. The right-hand/left-hand transmission line can be designed in the form of zig-zag pattern with sharp corners and only the right-hand transmission line in the form of sinusoidal patterns with smooth corners. In this presentation, we demonstrate that transmission lines of this kind can be used to realize highly efficient leaky wave antennas with broadband impedance matching and high gain characteristics in the Ku-band. Dispersion analysis and ladder network analysis have been performed for investigating the performance of the proposed designs. The sharpness of the bends periodically distributed along the body of the antenna has been used to our advantage for frequency scanning in the left-hand and right-hand quadrants at different frequencies. The proposed bending technique has been proven to be instrumental in achieving the desired characteristics of low profile leaky wave antennas.

A Dual-Beam Leaky-Wave Antenna Based on Squarely Modulated Reactance Surface

“…The distribution of surface impedance within one period is modulated as described in Figure 1 with X s = 430 Ω and p = 30 mm (10 unit cells per period). The desired radiation angle is set to be θ = 20 • by using Equation (8). The simulated radiation patterns of different modulation methods at 8.5 GHz are shown in Figure 6.…”

“…The desired radiation angle is set to be θ = 20° by using Equation (8). The simulated radiation patterns of different modulation methods at 8.5 GHz are shown in Figure 6.…”

“…Compared with uniform LWAs, periodic LWAs exhibit a large scanning range and flexible design schemes, which make them widely used in millimeter-wave bands [5,6]. One approach to achieving beam-scanning capability is utilizing the periodical shape changing of transmission line (such as triangle-truncated double-side parallel-strip lines [7] and bends of sharpness [8]). Another demonstrated method is sinusoidally modulating the surface impedance of the LWA [9][10][11][12].…”

A miniaturized mm‐wave leaky wave antenna based on CRLH slow‐wave SIW for symmetric wide angle beam scanning

“…It has a length of 4.85λ and 85% radiation efficiency. Kandwal et al have proposed a low‐profile LWA using a bending technique for wideband beam scanning in Ku‐band with a peak gain of 14 dBi 14 . Similarly, several SIW LWAs are presented including high gain LWA with backward scanning, 15 resonant cavity LWA Structure for 5G applications, 16 circularly polarized LWA, 17 compact omnidirectional LWA, 18 asymmetrical SIW‐based LWA with continuous beam scanning, 19 LWA with beam scanning from backfire using odd‐mode spoof surface plasmon polaritons, 20 Archimedean spiral slotted LWA, 21 and orthogonal printed microstrip antenna arrays for 5G Millimeter‐Wave beam scanning application 22 …”

A Wide Frequency Scanning Printed Bruce Array Antenna with Bowtie and Semi-Circular Elements

“…Planar periodic LWAs are low-profile, relatively easier to fabricate, and can scan in the backward or the forward endfire direction with a fan-beam radiation pattern with frequency tuning. Several types of LWAs based on a range of technologies have been proposed in the scientific literature, including periodically meandered rampart array [16], sharpening the bends [17], squarely modulated reactance surface (SquMRS) [18], composite right/left-handed structures (CRLH) [19,20], slot or coplanar lines [21], substrate integrated waveguide (SIW) structures [22][23][24][25][26][27], Goubau line structures [24], spoof plasmon transmission line (SSP-TL) structures [25], and periodically loaded microstrip structures [26].…”