Optimization Procedure for Planar Leaky-Wave Antennas With Flat-Topped Radiation Patterns

Abstract

International audienceWe describe here an optimization procedure to shape the radiation pattern of planar two-dimensional (2-D) leaky-wave antennas. The structures under investigation are superstrate configurations made by partially reflecting screens (impedances sheets) over a ground plane and excited by open-ended waveguides. The antenna configuration providing the required radiation pattern is obtained by resorting to an ad hoc optimization procedure that minimizes the mean squared error between the target pattern and the actual radiated far field. The radiated field is analytically evaluated using a Green's function spectral approach to speed up the optimization process. Several kinds of radiation patterns can be obtained using the proposed algorithm. In this work, we focus our attention on flat-topped radiation patterns, suitable as element pattern for phased array antennas covering a limited angular field of view such as those considered for space applications. The proposed procedure is validated by full-wave results and measurements

Pattern synthesis for multi‐layered perforated dielectric superstrate loaded patch antenna with equal E / H beamwidth

“…The superstrates are formed by perforated Rogers 6010LM. The optimisation frequency is set as 13.85 GHz with the requirements of side lobe level S and half 10 dB beam width θ 1 , set in (11), to be −16 dB and 20° respectively. In the optimisation, ε r1 and ε r3 equal to 1. ε r2 and ε r4 are varied from 1.9 to 10.2.…”

“…For antenna element, such as patch antennas, the pattern synthesis is based on the control of the excitation of resonant modes on the patch [2]. Alternatively, the superstrates using homogeneous dielectric structure (HDS) and/or periodic metal structure (PMS) have been found to be very useful in the pattern synthesis in spatial domain or spectral domain [3][4][5][6][7][8][9][10][11][12][13][14]. In [15], it is shown that these two structures can have same reflection coefficients and may provide almost identical effect.…”

“…In some applications, it was found that the HDS is a better choice [16]. Since the spectral domain method takes into account the position and nature of the feeding sources, it results in more accurate results and general procedure [11]. Although to control radiation patterns using the HDS based on spectral Green's functions (SGFs) were developed long before [5][6][7], this technique has been continuously bringing interesting opportunities on antenna synthesis.…”

Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings

“…Besides, internal stress between high and low refractive index quarter-wave layers also hinders the utility of thin-film devices in high power laser system [2]. Angular filters or spatial filters also received much attention since they are widely used in focus-free system [3,4], solar cell [5,6] and free space optical telecommunication [7,8]. Candidates of angular selectivity schemes include multi-layer thin-film [9][10][11], photonic crystals [12][13][14], volume bragg gratings [15][16][17] and rugate thin-film [18][19][20].…”

Microstrip tapered traveling wave antenna for wide range of beam scanning in X‐ and Ku‐bands

“…Thus, this microstrip TWA design has advantages of simple design schematic, low profile, and easy impedance matching. TWAs have been studied as solutions for gain enhancement of simple radiating sources, side‐lobe level reduction, and radiation pattern reconfiguration . By designing a TWA for RADAR systems in Reference , an effective continuous scanning has been achieved with a small increase in the feeding signal's frequency, thus it is possible to optimize the range and propagation pattern of the radar array, and steer the pattern of antenna for a scanning in time.…”