Three‐layered balanced circularly polarized slot antenna with high common‐mode suppression

In this article, a coplanar waveguide (CPW) fed 45 tilted fractal inspired slot antenna to achieve wideband circular polarization is presented. A fractal-square slot is etched from the ground plane and rotated by 45 . The fractal slot is excited by the CPW fed monopole antenna. To achieve wideband circular polarization, asymmetric arm length of the fractal slot is used. The proposed antenna is fabricated and tested. The measured impedance bandwidth (|S11| < −10 dB) is 22.5% (3.6-4.57 GHz) for Band-1 and 63.5% (5.1-10.1 GHz) for Band-2, and measured 3 dB axial ratio bandwidth is 34.7% (6.37-9.05 GHz). Experimental results show that the proposed antenna generates right-hand circular polarization in the +Z direction. Left-hand circular polarization can be achieved by tilting the fractal slot by −45 . K E Y W O R D S axial ratio, circular polarization, CPW fed monopole, fractal slot antenna

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

A coplanar waveguide fed tilted fractal inspired slot antenna for wideband circular polarization

Saraswat

Harish

2019

“…Researchers have also presented many single‐ended dual‐band CP antennas of different structures 2‐9 . Although differentially fed single‐band CP antennas, (such as, the substrate‐integrated waveguide‐fed cavity‐backed aperture antenna in Reference 10, the cross‐dipole antenna in Reference 11, the printed slot antennas [PSAs] in References 12, 13, and the quasi‐self‐complementary antenna in Reference 14) have also been proposed, they are relatively scant. Furthermore, differentially fed dual‐band CP antennas are even scarcer in the literature, with only a few works implemented using microstrip patch, 15 loop, 16 and dielectric resonator 17 structures.…”

Section: Introductionmentioning

confidence: 99%

Differentially fed dual‐band circularly polarized printed slot antenna with high common‐mode rejection

Lee

Huang

Hsu

2020

Self Cite

This letter proposes a newly designed differentially fed dual‐band circularly polarized (CP) printed slot antenna (PSA). The antenna consists of two oppositely fed halberd‐shaped strips and an S‐shaped slot. By configuring the antenna structure in rotationally symmetric fashion, the fields radiated by any two rotationally symmetric parts of the CP PSA will be constructive when excited differentially and destructive when in common‐mode (CM) operation. Thus, good differential‐mode (DM) performance and high CM rejection can be achieved. In particular, in both CP bands the radiation patterns of the proposed antenna are of the same CP sense, and the CP beams are wide and stable. Measurement shows the proposed differentially fed dual‐band CP PSA has a lower (higher) 10‐dB DM impedance band of 2.09 to 2.85 (5.06‐5.89) GHz and a 3‐dB DM axial‐ratio band of 2.32 to 2.59 (5.13‐5.86) GHz, corresponding to a CP fractional bandwidth of 10.9% (13.3%). Besides, in the displayed frequency region of 2‐6 GHz, the CM signals can be effectively suppressed, with the measured CM return loss smaller than 2.96 dB. The conversion of DM input signals into CM reflected signals is even smaller, with the measured DM‐to‐CM conversion less than −32 dB.

Differentially fed CP antenna with quasi‐self‐complementary semicircular‐ring structure

Lee

Hong

Chen

et al. 2018

Self Cite

This article presents a new design of a common‐mode suppressed differentially fed circularly polarized (CP) antenna using a quasi‐self‐complementary (QSC) structure. The antenna radiating element consists of a semicircular‐ring radiating patch and its complementary radiating slot counterpart. The design idea for producing CP radiation is based on field orthogonality of the QSC structure. For better impedance matching, a fan‐shaped notch (stub) around the feeding position was cut from (implemented in) the semicircular radiating patch (slot). In addition, to improve the axial ratio, a QSC semielliptical structure is embedded in the central area of the antenna. For the designed differentially fed CP antenna, measurement shows that the differential‐mode (DM) operating band with return loss >10 dB covers 4.76‐6.38 GHz. The measured DM 3‐dB axial‐ratio band is 4.95‐5.43 GHz. Also, very good common‐mode (CM) suppression is observed with the measured CM reflection coefficient >−1.21 dB in 4.50‐6.5 GHz.