Wideband Millimeter-Wave End-Fire Magneto-Electric Dipole Antenna Fed by Substrate Integrated Coaxial Line

A wideband endfire magnetoelectric (ME) dipole antenna fed by substrate integrated coaxial line (SICL) is presented. Endfire radiation is achieved by the combination of a horizontally oriented quarter-wave shorted patch and a dipole array loaded at the patch aperture. A direct-feeding mechanism based on the SICL structure is developed to excite the ME-dipole antenna. The proposed feeding method provides a simple yet effective mean of wideband impedance tuning. The antenna exhibits a wide impedance bandwidth of 77%, covering from 23.1 to 52 GHz, and a small lateral size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.32\lambda _{0}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> refers to the wavelength in free space at the center frequency, i.e., 38 GHz). In addition to its wideband performance and compactness, highlights, including a stable gain of around 5.5 dBi, low backward radiation, and low cross polarization, are also achieved. In particular, the proposed design outperforms most state-of-the-art millimeter-wave endfire antennas with a notable bandwidth.

A compact magnetoelectric (ME) dipole antenna element is proposed for design of wide beam steering arrays in the 5G millimeter wave (mm-wave) bands n257, n258 and n261. The antenna employs an substrate integrated coaxial line (SICL) based feed. The SICL line is transformed into a coplanar waveguide (CPW) to enable feed for ME dipole antenna. With adoption of a U-shaped shorting strip and SICL-CPW-based feed, the element achieves an -10 dB impedance bandwidth (IBW) of 22.4% at the center frequency (f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> ) of 26.8 GHz. Notably, the antenna offers ~ 100° of 3 dB beamwidth and a compact size of 0.32Ao x 0.32Ao, where Ao is free space wavelength at f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> . Using full-wave simulations, an 8-element uniform linear array (ULA) is shown to exhibit fractional IBW of 19%, max gain > 15 dBi with large beam steering angles up to 56°. The antenna can be easily fabricated using standard four layer printed circuit board (PCB) technology on Rogers 5880 dielectric laminates.

In this paper, a 1×4 dual polarized mod-ified dipole antenna array fed by Substrate Integrated Coaxial Line (SICL) is presented in Ka-band. The pro-posed array is achieved using two orthogonal radiating dipole antennas employing the standard ±45° slant technique. The elementary antenna is implemented by two 45° tilted modified dipole antennas printed orthogonal to each other on the top plate of substrate. The other dipole arm is implemented using the middle plate of SICL feeding network. The polarization of the antenna is controlled by exciting the antenna through either of the two feeding ports. A 1×4 stacked array of proposed antenna using L-bent SICL feeding network is utilized to obtain a gain of 7.6 dBi while maintaining good isolation. The proposed antenna resonates at 26 GHz exhibiting wide impedance bandwidth for the two polarization and co-pol to cross-pol ratio better than 23 dB. SICL helps in achieving a compact design by eliminating balun to feed the two arms of the dipole. Moreover, the feed network is compact and attains good isolation due to shielding. Another advantage of designing the antenna in SICL technology is the improvement in front-to-back ratio caused by the reflection of back radiations from the ground plates of SICL feeding network. This antenna finds its utility in n258-NR (New Radio) 5G spectrum endfire applications centered around 26 GHz.

A dual‐polarized aperture‐coupled magnetoelectric (ME) dipole antenna is presented in this paper. The feeding network is based on substrate‐integrated coaxial lines (SICLs). To describe the effect of the SICL on improving the isolation, the ME dipole with another two different feeding configurations, microstrip lines and striplines, respectively, is compared. As such, the coupling between the transmission lines is tremendously reduced and the isolation between the two input ports of different polarization is enhanced. An antenna prototype is fabricated and tested, exhibiting good performances, including an isolation level of higher than 30 dB between the two input ports and gains of more than 9.5 dBi. Besides, the proposed design is capable of achieving stable directional radiation patterns with cross‐polarization levels lower than −22 dB and back radiation levels lower than −24 dB.

A wideband compact magnetoelectric (ME) dipole antenna is investigated for millimeter-wave applications. First, an aperture coupled ME dipole is proposed with wideband and low profile. Next, transverse slots are added to miniaturize the antenna. The radiation performance of the higher-order mode is also improved. The antenna is finally miniaturized to 2.5×3.3 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ( 0.27 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.35 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , where λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the wavelength in free space at center frequency) when it is used in the array environment. A bandwidth of 48.8% (24.3-40 GHz) for SWR <; 2 can be achieved, with unidirectional radiation performance over the operating band. By combining the proposed compact antenna with an eight-way substrate integrated coaxial line (SICL) feed network, a 1 ×8 linear array is designed, fabricated, and measured. Good beam scanning capability is also verified by active simulation. With the advantages of wide bandwidth, compact size, promising radiation pattern and wide-angle beam scanning potential, the proposed antenna would be attractive for millimeter-wave devices and antenna in package (AiP) applications.

This paper presents Substrate Integrated Coaxial Line (SICL) fed wideband Multiple-Input Multiple-Output (MIMO) antenna array for 5G endfire applications. The radiating element in the array is a modified half-wavelength dipole antenna formed by tilted dipoles at ±45° to avoid overlapping between successive element in the array configuration. One arm is placed on the top while the other arm is placed on the bottom substrate and are respectively fed by top and middle plate (using a feeding via) of SICL line. The out of phase surface current of SICL feed line is utilized to successfully excite the dipole antenna. The top-bottom arrangement of the arms of the dipole antenna enables further compactness in the dimension of the array. SICL technology adds another advantage by reducing the coupling in the other port when one port is excited thereby high isolation is achieved using SICL. A four element MIMO antenna array for 360° azimuth coverage is proposed to exhibit a gain of 6 dBi with wide impedance bandwidth of 5.6 GHz and cross-polarization level below 13.6 dB at 28 GHz. The proposed MIMO antenna array is a potential candidate for 5G endfire applications in customer premises equipments (CPEs).

This paper presents an end-fire magneto-electric (ME) dipole antenna fed by substrate integrated coaxial line (SICL). End-fire radiation is obtained by combining a horizontally-oriented quarter-wave shorted patch and a loaded dipole array. An SICL direct-feeding scheme is applied to provide a simple and wideband excitation of the ME-dipole antenna. Experimental results verify that the proposed antenna exhibits a wide impedance bandwidth of 77%, a stable gain of around 5.5 dBi, and a compact lateral size of 0. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$32\lambda_{0}$</tex> .

Substrate Integrated Coaxial Line (SICL) is a kind of planar coaxial transmission line, which has completely shielded and non-dispersive structure. SICL has the characteristics including wide band, low loss and miniaturization. This paper researched a monopole antenna fed by SICL. A triangle monopole was adopted as the radiator with the frequency range from 1.35GHz to 1.65GHz. The SICL feeding structure was designed and simulated through the full wave electromagnetic simulation technique. The simulated voltage standing wave ratio (VSWR) of designed monopole antenna was less than 2 within the operating frequency range of 1.32GHz to 1.66GHz, and the relative frequency band was about 20%. The designed antenna achieved the anticipated gains which were higher the 2dBi for the operational frequency range. The radiator size of monopole antenna was about 33mm X 15mm × 2mm, and antenna miniaturization was achieved. The discussed monopole antenna fed by SICL showed the nearly omnidirectional radiation pattern and high radiation efficiency. Moreover, it had a simple structure, which was favorable for the practical application.

When designing a microwave circuit involving substrate integrated coaxial lines (SICLs), it is important to know what real crosstalk between SICLs is. A measured crosstalk will be a good reference value in a practical design. In addition, it is also needed to compare and check the crosstalk from the simulation and calculation formula with measured results. However, it is very difficult to measure the crosstalk between SICLs because it is theoretically very low. In this study, for the first time, the crosstalk characteristics of a SICL are evaluated through experimental design and measurements. By adjusting the layout of the structures and implementing controlled experiments, interference caused by the presence of leaks and radiation at the interface and structural transitions is effectively suppressed. The experimental results show that for two parallel SICLs with a length of 30 mm and an interval of 5 mm, the isolation is greater than 80 dB for the measured frequency range of 1–8 GHz, significantly better than the results of the grounded coplanar waveguide (GCPW).

In this paper, a dual-polarized wide-beamwidth magneto-electric (ME) dipole antenna for the fifth generation (5G) mobile communications is proposed. The proposed ME dipole antenna is printed on several dielectric substrates for easy fabrication. By applying a quadrate fence around the ME-dipole antenna, wide-beamwidth characteristics for both E- and H-planes can be obtained in dual linearly polarized directions. The proposed antenna realizes a half-power beamwidth (HPBW) of 129.1 ° in E-plane and another 100.4° in H-plane at 3.4 GHz, while 151.6° in E-plane and 94.2° in H-plane at 4.9 GHz can also be achieved. An overlapped impedance bandwidth (<-10 dB) between the two ports of 63% (2.76-5.3 GHz) with gain of approximately 5 dBi can be attained.

A new substrate integrated coaxial line (SICL) is proposed at 45 GHz for low loss and small size. The insertion loss of designed transmission line is less than 0.2 dB. Then, a high gain cavity-backed antenna array based on the SICL structure is proposed for Q-band applications. The antenna array consists of 1×4 cavity-backed patch antenna array, T-junction power divider based on SICL, and SICL to ground coplanar waveguide (GCPW) transition. The -10 dB impedance bandwidth is 11.44 GHz (25.42%). The gain is 15.8 dBi at 45 GHz.

A novel magneto-electric dipole antenna with dual linear polarization, ultra-wideband, and good unidirectional radiation is proposed. It consists of two bowtie-shaped electric dipoles, two orthogonally placed Γ-shaped feeding structures, four parasitic patches, and a metal cylindrical cavity. In order to illustrate the operating mechanism, the radiation field is simulated and analyzed at lower, medium, and higher frequencies. Three operating modes (electric dipole mode, ME dipole mode, and magnetic dipole mode) are found and discussed to show the ultra-wideband radiation. Especially, the ME dipole mode is analyzed in detail. By adding four parasitic metal patches, the boresight gain at the lower and higher bands is enhanced. At 1.75 and 5.6 GHz, the boresight gain improves 1.65 and 2.8 dB, respectively. Additionally, the height of the cylindrical cavity is also analyzed to show its effect on VSWR and boresight gain. Finally, a prototype is designed, fabricated, and measured. Measured results show that the impedance bandwidth for VSWR <2 is up to 92.3% (from 2.1 to 5.75 GHz) and 103% (from 1.8 to 5.65 GHz) at the two feeding ports, respectively. In its impedance bandwidth, the boresight gain is 8.75 ± 1.95 dBi and 8 ± 3.3 dBi at two ports, respectively. And, the radiation patterns in the operating band show a unidirectional radiation characteristic. Therefore, the proposed antenna can be a candidate in the future UWB communication system.

In this paper, ultra-wideband (UWB) Marchand baluns using substrate integrated coaxial line (SICL) technology are first proposed. SICL is a shielded planar coaxial line, which is very suitable for wideband and high-speed applications due to its broad unimodal operation band, low insertion loss, very small dispersion, and easy integration with other planar circuits. In order to achieve wider bandwidth and better VSWR performance of the SICL balun, a pair of quarter-wave impedance transformers are inserted into the balanced line. The impedance characteristics of the proposed SICL baluns are analyzed, and the parameters that determine the balun bandwidth are discussed. Then, curves of the balun resistance, reactance, and the SICL characteristic impedance are presented. According to these curves, the design parameters of the proposed SICL baluns can easily be determined. To verify these ideas, an UWB SICL single balun and an UWB SICL dual balun are designed, fabricated, and measured. Both full-wave simulated and measured results are presented, and good agreement between them is observed. The proposed SICL baluns have a simple structure and good performance, which are suitable for applications in UWB communication systems.

This paper presents a novel technique to implement crossed dipole antenna fed by Substrate Integrated Coaxial Line (SICL) technology. The inherent advantage of out of phase surface current of the SICL transmission line is utilized efficiently to excite the two dipole antennas. The crossed dipole is implemented such as to obtain dual band response at 26 GHz and 28 GHz. Two ±45° inclined dipoles are printed on the top/bottom of the substrate and simultaneously fed by top/bottom plate of the SICL line. The other arm of the dipole is printed in between the two substrate of the SICL line and is excited by the middle strip of the SICL line. A SICL 1:4 power divider is employed to feed four crossed dipole antenna to form an array. The array exhibits a gain of 9.7 dBi and 10 dBi at 26 GHz and 28 GHz respectively with wide impedance bandwidth of 3.1 GHz. The cross polarization level better than 20 dB and Front-to-Back Ratio better than 17 dB is obtained for the proposed design. The proposed antenna finds its suitability for the much focused 5G millimeter wave frequency bands.

A millimeter-wave low-profile magneto-electric(ME) dipole antenna is presented in this paper. The proposed ME dipole antenna is designed on two pieces of substrate with different materials and fed by aperture-coupled technique. Unlike the previously reported ME dipole antennas, there is no verticalcavity serving as a magnetic dipole in this design, while the magnetic dipole is formed by the gap between the two horizontal patches, this design makes the geometry of the ME dipole antenna simple acid easy to be fabricated. Simulated results show that the proposed ME dipole has impedance bandwidth (VSWR≤2) of 29.1% from 23.5 GHz - 31.5 GHz and a stable high gain of 8.3 ± 0.7 dBi across the operating frequency band.