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

2020 ◽  
Vol 10 (3) ◽  
pp. 962
Author(s):  
Hao Yu ◽  
Kuang Zhang ◽  
Xumin Ding ◽  
Qun Wu
Keyword(s):  
Transmission Lines ◽  
Near Field ◽  
Attenuation Constant ◽  
Leaky Wave ◽  
Flexible Control ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Dual Beam ◽  
Phase Constant ◽  
Good Agreement

In this paper, a novel dual-beam leaky-wave antenna (LWA) based on squarely modulated reactance surface (SquMRS) is proposed. The equivalent transmission lines model is utilized to characterize the field distributions of surface wave guided by the SquMRS. The calculated dispersion characteristics of SquMRS are verified by the simulated results, and it is demonstrated that SquMRS exhibits a more flexible control of phase constant and attenuation constant compared with traditional sinusoidally modulated reactance surface (SinMRS), which means SquMRS has a great potential for near-field focusing and far-field beam shaping. On this basis, a versatile method, based on a superposition of individual modulation patterns, was used to generated two beams with almost identical gain at 8.5 GHz. The measured results show that the gains are 10 dBi and 8.2 dBi at θ1 = −30° and θ2 = 18°, respectively, and the radiation efficiency is 83%, which shows good agreement with the simulated results.

scholarly journals Design of leaky-wave antennas with transverse slots for end-fire radiation with optimized radiation efficiency

2019 ◽  
Vol 17 ◽  
pp. 71-75
Author(s):  
Thomas Vaupel ◽  
Claudius Löcker
Keyword(s):  
Modal Analysis ◽  
Free Space ◽  
Waveguide Mode ◽  
Wave Mode ◽  
Main Beam ◽  
Attenuation Constant ◽  
Leaky Wave ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Phase Constant

Abstract. A substrate integrated waveguide (SIW) with transverse slots on the top plane can be used to design an effective leaky-wave antenna with good frequency beam-scanning and platform integration capability. For a main beam near end-fire, the phase constant of the radiating wave must be near to the free space wavenumber or slightly larger. In this context, the modified Hansen-Woodyard condition gives an optimum phase constant to maximize the directivity at end-fire. For the analysis of the wave propagation we have implemented a modal analysis for rectangular waveguides with transverse slots. Near end-fire, three types of modal solutions exists, a leaky improper mode, a surface wave mode and a proper waveguide mode. The leaky mode can reach phase constants larger than the free space wavenumber to fulfill the Hansen-Woodyard condition, but loses strongly its physical significance in this slow wave region, thus the excitation of the leaky-wave becomes negligible there, whereas the proper waveguide mode is dominant but exhibits only a negligible radiation loss leading to a strong drop of the antenna efficiency. Therefore, the optimum efficiency of 86 % for maximizing the gain as proposed in the literature cannot be reached with this kind of leaky wave antenna. But it will be shown in this contribution by analyzing antenna structures with finite aperture lengths, that the efficiency can reach nearly 100 % if the phase constant of the leaky-wave meets exactly the free space wavenumber (ordinary end-fire condition) and the aperture length is adjusted with regard to the attenuation constant of the leaky-wave from the modal analysis. For a given aperture length, a procedure is outlined to adjust the attenuation constant in several steps at the desired ordinary end-fire frequency to reach maximum gain and efficiency.

scholarly journals Sidelobe Suppression in Array-Pattern Synthesis Using Periodic Leaky-Wave Antenna and Binomial Array

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Hicham Aziz ◽  
Mahmoud Moubadir ◽  
Abdelkrim Farkhsi ◽  
Naima Amar Touhami
Keyword(s):  
Antenna Array ◽  
Sidelobe Suppression ◽  
Sidelobe Level ◽  
Leaky Wave ◽  
Pattern Synthesis ◽  
Array Pattern ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Measurement Results ◽  
Good Agreement

This paper presents the conception and realization of a 2D antenna array using periodic leaky-wave antenna (PLWA) and the binomial array (BA) at 6 GHz as the application of WLAN. The series array of periodic leaky-wave antenna was provided by an array of five rectangular Patches connected by cross lines. The nonuniform amplitudes of the binomial array are used to reduce the sidelobe level; in this way, the center source radiates strongly on the broadside. The prototype of the proposed 2D antenna array is designed, fabricated, and tested. A good agreement is obtained between simulated and measurement results.

Sign in / Sign up

Export Citation Format

Share Document