Frequency-scanned leaky-wave antenna from negative refractive index transmission lines

2007 ◽  
Author(s):  
C. Liu ◽  
W. Menzel
Keyword(s):  
Refractive Index ◽  
Transmission Lines ◽  
Negative Refractive Index ◽  
Leaky Wave ◽  
Leaky Wave Antenna ◽  
Wave Antenna

T-type folded SIW-based leaky-wave antennas with wide scanning angle and low cross-polarization

2021 ◽  
pp. 1-6
Author(s):  
Shixiao Xiao ◽  
Lianwu Yang
Keyword(s):  
Transmission Lines ◽  
Cross Polarization ◽  
Frequency Range ◽  
Leaky Wave ◽  
Scanning Angle ◽  
Sinusoidal Modulation ◽  
Wave Characteristics ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Transverse Slot

Abstract In this paper, a leaky-wave antenna (LWA) with wide scanning angle and low cross-polarization is proposed based on a T-type folded substrate-integrated waveguide (FSIW). Transverse slots with a sinusoidal distribution pattern are etched on the surface of the FSIW so that transmission lines with slow-wave characteristics can excite and radiate −1 order harmonics. The length of the transverse slot affects the dispersion characteristics of the transmission line, and the sinusoidal modulation period controls the operating range of the LWA. In the frequency range of 8.3–15 GHz, the proposed LWA achieves a wide scanning ranging from backward −42° to forward +68° continuously. The cross-polarization of the beam is also kept at less than −30 dB during this scanning. A prototype is fabricated and measured to confirm the design, and the measured results show an agreement with the simulated one.

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 Leaky wave antenna with amplitude controlled beam steering based on composite right/left-handed transmission lines

2010 ◽  
Vol 8 ◽  
pp. 27-32 ◽  
Author(s):  
M. A. Eberspächer ◽  
T. F. Eibert
Keyword(s):  
Transmission Lines ◽  
Beam Steering ◽  
Main Beam ◽  
Beam Direction ◽  
Leaky Wave ◽  
Microstrip Technology ◽  
Left Handed ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Unit Cells

Abstract. An antenna comprising two different composite right/left-handed transmission line structures is proposed which enables easy beam steering at an operation frequency of 10 GHz. The composite right/left-handed transmission lines are based on planar, periodically arranged via free unit cells, implemented in microstrip technology. Both transmission lines exhibit the infinite wavelength phenomenon which occurs at 9.72 GHz and 9.89 GHz, respectively. Thus, operating the different leaky wave structures at 10 GHz, radiation with azimuth angles of ±8° and ±17° can be achieved depending on the selected input port. In order to obtain a tunable main beam direction, the radiation patterns of both structures are superimposed by feeding them simultaneously. The influence of each guiding structure, and hence the direction of the main beam, can be controlled via the feeding amplitude. As a result of this, the beam can be steered between ±17° with a gain of up to 10 dBi. The guiding structures are arranged in parallel with a clearance of a=12.2 mm which is less than half of the wavelength in free space. This allows in a further step the attachment of additional guiding structures in order to increase the tunable angle range or creating an antenna array with a small beamwidth in the elevation plane without the occurrence of grating lobes. An antenna prototype was fabricated and validated by measurements.

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