Ladder Antennas for Dual Circular Polarization

Hirose, Kikuji; Shibasaki, T.; Yoshida, Yusuke; Nakano, Hisamatsu

doi:10.1109/lawp.2012.2220751

Cited by 9 publications

(5 citation statements)

References 4 publications

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“…A matched termination [1,2] is not used to avoid decreased radiation efficiency. The antenna is made of wires with a radius ρ [4,11].…”

Section: Bent Line Antennamentioning

confidence: 99%

“…For this, we chose the loop perimeter P and path length along the periodical bend (d + 2L s + P − δ) to be 1λ 0 and 2λ 0 , respectively, where λ 0 is the free-space wavelength at a test frequency f 0 . The other configuration parameters are fixed to be (h, ρ) = (λ 0 /8, λ 0 /200) [9,11] throughout this paper. Note that the ground plane is assumed to be perfectly conducting and of infinite extent, and image theory [13] is used in the analysis.…”

Section: Bent Line Antennamentioning

confidence: 99%

“…Figure 1c shows an antenna configuration. We create the antenna using the bent line antenna in Section 2: Each loop gap is chosen to be δ = 0 (the two segments of length L s are replaced with a single one), and a stub of length ∆ is added to each loop [11]. The antenna is again designed for a CP beam in the +z-axis direction.…”

Section: Original Antennamentioning

confidence: 99%

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Bent and Branched Microstrip-Line Antennas for Circular Polarization

2022

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We analyze three transmission-line antennas using the moment method. Each line antenna comprises a coplanar feed line, loops, and straight segments connecting the loops and feedline. First, we investigate bent and branched line antennas with loops on one side of the feedline. It is found that the segment length affects both the beam direction and axial ratio for the bent line antenna; in contrast, it only affects the branched line antenna’s axial ratio, resulting in a more straightforward design. Subsequently, the branched line antenna is modified with loops on both sides of the feedline to enhance the gain. It is observed that the antenna shows a gain enhancement of 2.0 dB, maintaining the same axial-ratio bandwidth as that of the original branched line antenna. The simulated results are validated by experimental work.

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“…A matched termination [1,2] is not used to avoid decreased radiation efficiency. The antenna is made of wires with a radius ρ [4,11].…”

Section: Bent Line Antennamentioning

confidence: 99%

Section: Bent Line Antennamentioning

confidence: 99%

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Bent and Branched Microstrip-Line Antennas for Circular Polarization

2022

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“…Literature [3] reveals that the LP beam from the 1 g LPAnT can be changed into a circularly polarized (CP) beam by adding perturbation elements to the loop. This technique is applied to generation of CP beams in [4] [5]. These CP beams have unidirectional radiation using a conducting reflector, with distances from the loop to the reflector being  0 /4 [4] and  0 /8 [5].…”

Section: Introductionmentioning

confidence: 99%

“…This technique is applied to generation of CP beams in [4] [5]. These CP beams have unidirectional radiation using a conducting reflector, with distances from the loop to the reflector being  0 /4 [4] and  0 /8 [5].…”

Section: Introductionmentioning

confidence: 99%

Compound Metaloop Antenna for Circularly Polarized Beam Steering

2021

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A metaloop antenna (1FD-MetaLPA), made of C-type metaatoms and having a single feed point, F L ', is created to radiate a left-hand circularly polarized (LHCP) axial beam at a frequency of f LH-1FD = 2.55 GHz and a right-hand circularly polarized (RHCP) axial beam at a frequency of f RH-1FD = 3.45 GHz. It is revealed that the maximum gains at f LH-1FD and f RH-1FD are unbalanced. Subsequently, a number of C-type metaatoms are replaced by N-type metaatoms. The replacement generates a balanced gain of 7.1 dBi with an LHCP gain bandwidth of 7.7% and an RHCP gain bandwidth of 8.3%. The radiation efficiency under the balanced gain is 75% at f LH-1FD and 29% at f RH-1FD . Next, a large metaloop antenna that radiates a conical beam and has a feed point, F O , is concentrically added to the outside of the gain-balanced 1FD-MetaLPA. This antenna system is designated as the MetaLPA-plus. It is found that the MetaLPA-plus radiates an LHCP tilted beam at f LH-1FD and an RHCP tilted beam at f RH-1FD . The angle of depression (tilt angle) using equal amplitude excitation is  max = 20 o at f LH-1FD and  max = 15 o at f RH-1FD . These tilted CP radiation beams are rotated around the antenna axis with change in the excitation phases at points F L ' and F O . During the beamsteering, the gain for an LHCP wave is nearly constant, with a value between 5 dBi and 6.5 dBi. This also holds true for an RHCP wave. INDEX TERMSCircularly polarized wave, Dual band operation, Loop antenna, Metaatoms, Steerable beam.

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