Y-shaped Feeding Research Articles

Polarization-Orthogonal Co-frequency Dual Antenna Pair Suitable for 5G MIMO Smartphone With Metallic Bezels

This paper proposes a polarization-orthogonal co-frequency dual antenna pair suitable for fifth-generation (5G) multiple-input multiple-output (MIMO) smartphone with metallic bezels. The proposed spatial-reuse dual antenna pair consists of a split on the metallic bezel and a slot on the mainboard ground, where the slot is centered on the split. Two orthogonal degenerate characteristic modes operating at half wavelength including in-phase current and slot modes can be excited on the same antenna structure. An end-shorted microstrip line that crosses the split is used to excite the in-phase current mode, producing $y$ -polarized radiation, while a symmetrical slot-centered Y-shaped feeding network with its shorted ends crossing the slot is adopted to excite the slot mode, producing $x$ -polarized radiation. To the best of authors’ knowledge, this is the first time that a co-frequency dual antenna pair suitable for smartphone with metallic bezels is proposed. A sub-6 GHz dual antenna pair operating at 3.5 GHz that occupies a footprint of $25 \times 7 \times 1.5$ mm3 shows a simulated isolation better than −24.1 dB without any external decoupling measures and an envelope correlation coefficient (ECC) lower than 0.008. A four-antenna MIMO array is fabricated and measured to verify the feasibility. Across the operation band, the measured isolation of the antenna pair is better than −20.1 dB and other isolation levels are all better than −12.7 dB, the ECCs of any two antennas are lower than 0.13, and the total efficiency range of the four antennas is 35.2%~64.7%. The proposed dual antenna pair exhibits a great potential to be applied in future 5G MIMO smartphone.

Design of multiband multipolarised single feed patch antenna

A new low profile, multiband, multipolarised single feed antenna is designed. A corner truncated patch loaded with slots and a complementary split ring resonator is used to achieve three frequency bands with different polarisations. The antenna exhibits right-hand circular, linear, and left-hand circular polarisation at three different bands, respectively. To obtain circular polarisation, orthogonal modes are excited by truncating corners of the patch and etching slits. Single feed, single layer geometry with Y-shaped feed structure is employed. The antenna is fabricated on a low-cost FR4 substrate with an overall size of $70\, {\rm mm} \times 70\, {\rm mm}$70 mm×70 mm, and the proposed design has been verified experimentally. The selected frequency bands are centred at 2.313, 2.396, and 2.478 GHz, and they have -10 dB impedance bandwidths of 2.14, 2.50, and 2.42%, respectively. The first frequency band exhibits right-hand circular polarisation with a 3 dB axial ratio bandwidth of 0.85%. The second frequency band exhibits linear polarisation, whereas the third frequency band exhibits left-hand circular polarisation with a 3 dB axial ratio bandwidth of 0.81%.

Broadband and Low-Profile Microstrip Antenna Using Strip-Slot Hybrid Structure

In this letter, a low-profile microstrip antenna with strip-slot hybrid structure is proposed to enhance the bandwidth up to 41% within a height of $0.06\,\lambda _{{\rm{0}}}$ ( $\lambda _{{\rm{0}}}$ is the center operating wavelength in free space). The proposed antenna consists of four strips, which are separated by three narrow slots. By controlling the dimensions of the strips and the slots, dual modes, i.e., ${\rm{TM}}_{{\rm{10}}}$ mode and antiphase ${\rm{TM}}_{{\rm{20}}}$ mode, are excited and coupled to increase the operating bandwidth. The strip-slot hybrid structure can be excited with optimized impedance matching using an aperture-coupled Y-shaped feeding microstrip line. A prototype of the proposed antenna is constructed and tested. Experimental results show an impedance bandwidth of 41% for the reflection coefficient less than −10 dB, achieving an obvious improvement of operating bandwidth with a low profile of $0.06\,\lambda _{{\rm{0}}}$ .

A Dual-polarized Planar Antenna Using Four Folded Dipoles and Its Array for Base Stations

A ±45° dual-polarized base station antenna with a planar structure is proposed for 2G/3G bands. The +45° antenna and the −45° antenna share the same radiator, which is composed of four folded dipoles and four coplanar striplines. The coplanar striplines work as $\lambda $ /4 impedance transformers. Two Y-shaped feeding lines is designed to obtain a good impedance matching and a planar reflector is employed to achieve a stable radiation pattern. The antenna element has a wide impedance bandwidth of 27.8% with SWR 30 dB), a stable radiation pattern with 3-dB beamwidth 65° ± 5° in the horizontal plane, a high XPD and a high front-to-back ratio were achieved.

Asymmetrical coupling feed of circularly polarized microstrip antenna for bandwidth enhancement

This article presented a simple asymmetrical coupling Y-shaped feed for a square microstrip antenna to broaden circular polarization bandwidths. Because the asymmetrical Y-shaped feed provided two different couplings to a square radiator, the two lowest axial ratios with identical circular polarizations were obtained and independently controlled. As a result, two closely located axial ratios produce a broad 3-dB axial ratio bandwidth by optimizing the lengths of the Y-feed. Finally, the implemented antenna using the proposed feed behaved as predicted by the simulation results and successfully demonstrated improved axial ratio bandwidths with left-handed circular polarization characteristics. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1672–1675, 2016

A Polarization Diversity Patch Antenna with a Reconfigurable Feeding Network

This paper proposes a reconfigurable square-patch antenna with polarization diversity. The proposed antenna consists of a square radiating patch and a Y-shaped feed structure with two PIN diodes. The shape of the feed structure can be changed by adjusting the bias states of the two PIN diodes, which helps switch between two orthogonal linear polarizations. The polarization diversity characteristic is validated by the simulated current distribution and the measured radiation pattern.

A Broadband $\pm 45^{\circ}$ Dual-Polarized Antenna With Y-Shaped Feeding Lines

A broadband $\pm 45^{\circ}$ dual-polarized base station antenna is proposed for 2G/3G/LTE bands. The proposed antenna has Y-shaped feeding lines to impart a wide impedance bandwidth to it, and a rectangular box-shaped reflector to enhance its stability in radiation patterns over the operating frequencies. A prototype of the proposed antenna is designed, fabricated, and tested. The measured results show achievement of impedance bandwidth of 45% for $\hbox {SWR} at both ports, port-to-port isolation $>$ 25 dB , a stable radiation pattern with 3-dB beamwidth $68^{\circ}\pm 2^{\circ}$ at H-plane and V-plane, and a stable antenna gain of 8.2 $\pm$ 0.6 dBi from 1.7 to 2.7 GHz. A broadband dual-polarized antenna array with five elements for the band is developed for base station application. Measurements show achievement of array gain of 14.8 $\pm$ 1.4 dBi, 3-dB beamwidth $66.56^{\circ}\pm 2.22^{\circ}$ at H-plane at port 1 and $64.85^{\circ}\pm 4.96^{\circ}$ at port 2 with $\hbox {SWR} over the operating frequency band. Simulation results have a good agreement with measurement ones.

Reconfigurable Rhombus-Shaped Patch Antenna With Y-Shaped Feed for Polarization Diversity

In this letter, a reconfigurable rhombus-shaped patch antenna with a Y-shaped feedline for polarization diversity is proposed. This antenna exhibits a simple structure, which consists of a rhombus-shaped patch, two p-i-n diodes, and a Y-shaped feedline. The two p-i-n diodes are inserted in the gap between the rhombus-shaped patch and the Y-shaped feedline. In order to easily supply a dc bias voltage to the p-i-n diodes, a shorting pin is inserted in the center of the rhombus-shaped patch. The proposed antenna can be operated in two modes-the left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) modes-by electrically controlling the two p-i-n diodes. The measured 10-dB reflection coefficient and 3-dB axial-ratio bandwidths of the prototype antenna are approximately 5.62% and 2%, respectively.

Y형태의 급전 구조를 이용한 편파 변환 재구성 패치 안테나

본 논문에서는 Y자 형태의 급전 구조를 사용한 두 개의 편파 변환 재구성 패치 안테나를 제안하였다. 제안된 안테나는 정사각형 형태의 패치, Y자 형태의 급전 구조, 하나의 핀 다이오드, 다이오드를 동작시킬 DC bias 회로로 구성되어 있다. 구조적인 대칭/비대칭은 두 갈래로 갈라지는 Y자 형태의 급전부 왼쪽 라인에 삽입된 핀 다이오드의 on/off 상태에 의해 결정된다. 제안된 재구성 안테나는 핀 다이오드가 on 상태이면 급전부의 갈라지는 두 마이크로스트립 라인의 길이가 같아지게 되어 안테나는 선형 편파 특성을 나타낸다. 반면에, 핀 다이오드가 off 상태이면 급전부의 갈라지는 두 마이크로스트립 라인 중 한 쪽 라인의 길이가 나머지 한 쪽 라인의 길이보다 상대적으로 짧아지게 된다. 그러므로 안테나는 원형 편파 특성을 나타낸다. 측정 결과로부터 제안된 안테나는 좋은 임피던스 매칭과 축비 특성을 나타내며, 같은 주파수 대역에서 쉽게 편파 변환할 수 있다는 것을 확인할 수 있다. In this paper, a reconfigurable polarization patch antenna that uses a Y-shaped feed is proposed. The proposed antenna consists of a square patch, a Y-shaped feeding structure, a PIN diode, and a bias circuit for diode operation. The structural symmetry/asymmetry of the feeding structure is determined by the on/off operation of the PIN diode that inserted into the side of one of the lines of the Y-shaped feeding structure. For the proposed reconfigurable antenna, the two microstrip lines of the feeding structure have the same length when the PIN diode operates in the on state, and the antenna exhibits linear polarization(LP). On the other hand, when the PIN diode operates in the off state, the length of one side line of the feeding structure is relatively shorter than that of the other line. Therefore, the antenna exhibits circular polarization(CP). From the measurement results, it is found that the proposed antenna exhibits good impedance matching and axial ratio. In addition, polarization switching can be easily achieved in the same operating band.

A Novel Bidirectional Antenna With Broadband Circularly Polarized Radiation in X-Band

A novel bidirectional antenna with a broadband circular polarization (CP) property in X-band is proposed. The CP characteristics are simply achieved by the asymmetrical Y-shaped feeding line. Both the impedance bandwidth and the axial-ratio (AR) bandwidth can be greatly improved by a through-via that is in series with an inductive strip and the polygon slot structure. The antenna is fabricated and measured for verifying the theory. A good agreement is achieved between the simulated and measured results. The 10-dB return-loss bandwidth is 31.4%, in which the AR is less than 2 dB. The measured radiation pattern shows a near-symmetry bidirectional radiation with the peak gain of 4.6 dBi. This antenna is a good candidate as a unit element in beamforming array applications.

Polarisation diversity antenna with asymmetrical Y‐shaped feed structure

A reconfigurable antenna with polarisation diversity is proposed. The proposed antenna consists of a square radiating patch and a switchable Y-shaped feed structure. The radiating patch is fed by the switchable Y-shaped feed line to dynamically change the polarisation state. The novel structure described here enables matched input optimisation for both polarisations. Low cross-polarisation levels in the linear state and good axial ratios in the circular state are observed.

Multisegment microstrip patch antenna with Y-shaped feed

A new antenna structure comprising of multiple radiating microstrip patches, representing a figure of digit eight, proximity fed by a microstrip line is proposed. On a double-layered substrate of FR4, this antenna achieves multiband functionality in the range of 3.81–12.42 GHz, which covers IEEE 802.11a standards and is suggestive of reconfigurability in frequency and pattern. Details of the antenna design, measured and simulation results are presented. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2011. © 2011 Wiley Periodicals, Inc.

Circularly polarised square patch antenna with asymmetrical Y-shaped feed structure

A novel single-feed structure for circularly polarised square patch antennas is proposed and theoretically studied. The proposed antenna has a simple structure, consisting of a square radiating patch and an asymmetrical Y-shaped microstrip feed line. The two orthogonal modes with equal amplitude and ±90° out of phase are simultaneously excited by the suggested feed structure with two different branch lengths. It is shown that the proposed antenna has good circular polarisation characteristic.