Design of Wideband Dual-Circularly Polarized Endfire Antenna Array on Gap Waveguide

A wideband dual-circularly polarized (CP) linear antenna array is presented in this paper. Firstly, a dual-CP endfire antenna based on septum polarizer is designed as the element for the array. Secondly, the feeding network is realized by ridge gap waveguide. Then a 1 78 linear antenna array is built up by the elements. The proposed array antenna achieves wide impedance bandwidth of 44.6% with the reflection coefficient below -10 dB, the isolation between ports greater than 15 dB, and a wide 3-dB axial ratio (AR) bandwidth of 46.2%

Diseño de una antena modelo compact ACTSA para que opere en la banda de onda milimétrica

En el presente artículo se diseña una antena modelo Compact ACTSA tipo bocina utilizando el software ANSYS HFSS, donde se analiza el comportamiento de la antena en banda de onda milimétrica. Para esto, se realizan pruebas con distintos ajustes en las dimensiones del dieléctrico y la tierra para lograr que opere en la frecuencia de 60GHz. Se toman los resultados del coeficiente de reflexión (S1,1), el VSWR, Coeficiente de Reflexión, para establecer las características en forma y componentes que permitan un diseño acorde a la banda donde se implementa. Finalmente se encuentra el diseño que se ajusta a la frecuencia de 60 GHz, con VSWR de 1.04 dB y un patrón de radiación omnidireccional.In this article a Compact ACTSA model horn antenna is designed using the ANSYS HFSS software, where the behavior of the antenna in a millimeter waveband is analyzed. For this, tests are performed with different adjustments in the dimensions of the dielectric and the earth to get it to operate at the frequency of 60GHz. We take the results of the parameter (S1,1), the VSWR, Coefficient of Reflection, to establish the characteristics in form and components that allow me a design according to the band where it is implemented. Finally there is the design that fits the frequency of 60 Ghz, with VSWR of 1.04 dB and an omnidirectional radiation pattern

A CPW-fed Sigma-shaped MIMO Antenna for Ka Band and 5G Communication Applications, Journal of Telecommunications and Information Technology, 2018, nr 4

This article presents a MIMO compact antenna measuring 45×45×1.6 mm, on the FR4 substrate, proposed for Ka band and 5G communication applications. The proposed design is suitable to overcome the issues connected with massive MIMO. It has four-sigma-shaped radiating elements and a c-shaped ground plane with coplanar waveguide feeding. Its compact dimensions suit it for most existing communications systems. The aerial operates in the 21–30 GHz range, which covers Ka and 5G communication bands. The proposed antenna exhibits the average efficiency of more than 76% within its operating band and gives a minimum signal to noise plus interference ratio. The presented antenna covers several services, such as Ka band satellite downlink applications and future 5G communication applications

High Gain Broadband mm-Wave Antenna Arrays for Short-range Wireless Communication Systems

Recently, the ever-increasing demand for fifth-generation (5G) wireless applications has turned millimeter-wave (mm-wave) multi-beam array antenna into quite a promising research direction. Besides offering a remarkable bandwidth for high-speed wireless connectivity, the short wavelengths (1 to 10 mm) of mm-wave signals makes the size of the antenna array with beamforming network (BFN) compatible with a transceiver front-end. The high losses associated with mm-wave wireless links and systems considered the foremost challenge and may restrict the wireless communication range. Therefore, a wideband substrate integrated waveguide (SIW)-based antenna with high gain and beam scanning capabilities would be a solution for these challenges, as it can increase the coverage area of mm-wave wireless systems and mitigate the multipath interference to achieve a high signal to noise (S/N) ratio, and thereby fulfill the link budget requirements. This thesis focuses on the analysis and design of single- and multi-beam mm-wave antenna arrays based on SIW technology to fulfill the growing demand for wideband high-gain planar antenna arrays with beam steering capability at V-band. A tapered slot antenna (TSA) and cavity-backed patch antenna are used as the main radiators in these systems to achieve high-gain and high efficiency over a wide range of operating frequencies. Accordingly, numerous design challenges and BFN-related issues have been addressed in this work. Firstly, an antipodal Fermi tapered slot antenna (AFTSA) with sine-shaped corrugations is proposed at V-band. The antenna provides a flat measured gain of 20 dB with a return loss better than 22 dB. In addition, A broadband double-layer SIW-to-slotline transition is proposed to feed a planar linearly tapered slot antenna (PLTSA) covering the band 46-72 GHz. This new feeding technique, which addresses the bandwidth limits of regular microstrip-to-slotline transitions and avoids the bond wires and air bridges, is utilized to feed a 1x4 SIW-based PLTSA array. Secondly, a new cavity-backed aperture-coupled patch antenna with overlapped 1-dB gain and impedance bandwidth of 43.4 % (56-87 GHz) for |S11| < -10 dB and an average gain of 8.2 dBi is designed. A detailed operating principle is presented. Based on the proposed element, an SIW based 1x8 array is constructed, whose beam-shape is synthesized by amplitude tapering according to Taylor distribution to reduce the sidelobe level. Moreover, a four-layered 4x4 cavity-backed antenna array with a low-loss full-corporate SIW feed network is implemented for gain and aperture efficiency enhancement. The measured results exhibited a bandwidth of 38.4 % (55.2-81.4 GHz) for |S11| < -10 dB and a gain of 20.5 dBi. A single-layer right-angle transition between SIW and air-filled WR15 waveguide along with an equivalent circuit model is introduced and used to measure the performance of both proposed linear and planar arrays. Thirdly, two 1-D scanning multi-beam array designs based on SIW technology, at 60 GHz, have been presented. The first design is a compact multi-beam scanning 4x4 slot antenna array with broadside radiation. The BFN is implemented using a dual-layer 4x4 Butler matrix, where the 450 and 00 phase shifters are designed on a separate layer with different permittivity, resulting in a significant size reduction compared to a conventional single layer. A detailed theoretical analysis, principle of operation and the circuit-model of the proposed phase shifter have been discussed, showing less desperation characteristics compared to ordinary phase shifters. The measured results show an azimuthal coverage of 1210. The second design is a wideband high gain multi-beam tapered slot antenna array with end-fire radiation. An SIW Butler matrix with a modified hybrid crossover is used as a BFN. The fabricated prototype exhibits a field of view of 970 in the azimuthal plane, with measured gain ranges from 12.7 to 15.6 dBi. Lastly, a novel three-layered SIW-fed cavity-backed linearly polarized (LP) patch antenna element is presented, covering a bandwidth of 36.2 % (53-76.4 GHz) with a flat gain ranging from 7.6 to 8.2 dBi. A compact two-layered beam forming network is designed with a size reduction of 28 % compared to a standard one-layered BFN without affecting its s-parameters. The results show that the impedance bandwidth is 31.1 % (51.5-70.5 GHz) for |S11|<-16 dB with an average insertion loss of 1.3 dB. The proposed antenna element and BFN are employed to form a compact 2x2 multibeam array at 60 GHz for 2-D scanning applications. The array shows a bandwidth better than 27 % with a radiation gain of up to 12.4 dBi and radiation efficiency of 80%. The multi-beam array features four tilted beams at 330 from a boresight direction with 450, 1350, 2250 and 3150 in azimuth directions, i.e., on e beam in each quadrant

Wideband Dual-Circular-Polarization Antennas for Millimetre-Wave Wireless Communications.

PhD Theses.Millimetre-wave (mmWave) wireless communications has attracted great interest in recent years as a promising technology that can provide high data rate beyond 5G. Circular Polarization (CP) radiation is preferable to Linear Polarization (LP) in mmWave wireless communications, owing to the reliability of the wireless link it provides to suppress multi-path fading and polarization misalignment. Apart from the link robustness, high link capacity is also desirable by introducing technologies such as Polarization Division Multiplexing (PDM) or In-Band Full-Duplex (IBFD). Therefore, this research aims to design dual-circular-polarization (dual-CP) antennas with wide bandwidth and high port isolation to enable PDM or IBFD for mmWave wireless communications thereby achieving twofold spectral e ciency. The research work has been conducted in the following four parts. Firstly, a dual-CP horn antenna based on a stepped septum polarizer is designed in the W-band. By optimising the horn pro le, a wide bandwidth with good isolation is achieved in simulation and veri ed in experiment. Secondly, to further push the limits of the dual-CP antenna based on the stepped septum polarizer, a grooved-wall septum polarizer is proposed for the rst time with a 2-step design method to realize a dual-CP antenna with wider operating bandwidth and higher port isolation. Thirdly, in order to ease the fabrication di culty and further improve the antenna performance, a novel grooved-wall CP horn antenna is designed in simulation and veri ed in experiment in the W-band. The dual CP performance can be generated when used with an Orthomode Transducer (OMT), instead of a septum. Finally, this septum-free approach has been generalised to design a multi-section groovedi wall CP horn antenna with a low re ection coe cient over a wide bandwidth in the W-band. This horn antenna is demonstrated to be capable of achieving dual-CP with high isolation over a wide bandwidth when used together with an OMT

Nanodevices for Microwave and Millimeter Wave Applications

The microwave and millimeter wave frequency range is nowadays widely exploited in a large variety of fields including (wireless) communications, security, radar, spectroscopy, but also astronomy and biomedical, to name a few. This Special Issue focuses on the interaction between the nanoscale dimensions and centimeter to millimeter wavelengths. This interaction has been proven to be efficient for the design and fabrication of devices showing enhanced performance. Novel contributions are welcome in the field of devices based on nanoscaled geometries and materials. Applications cover, but not are limited to, electronics, sensors, signal processing, imaging and metrology, all exploiting nanoscale/nanotechnology at microwave and millimeter waves. Contributions can take the form of short communications, regular or review papers

Microstrip antenna design with improved fabrication tolerance for remote vital signs monitoring and WLAN/WPAN applications at mm-wave and THz frequencies

A novel approach is introduced to design microstrip patch antennas (MPAs) with improved fabrication tolerance for highly demanded Millimetre-wave (mm-wave) (30-300GHz) and Terahertz (THz) (0.3-3THz) frequency applications. The presented MP A designing method overcomes the challenges which exist with the fabrication and implementation of the conventional MP A designs at mm-wave and THz frequencies. The following research contributions have been added to the state-ofthe- art work: (i) designing of improved size MPAs at 60GHz, 1 OOGHz, 635GHz and 835GHz to prove the designing concept, (ii) detail measurements and analysis of Remote Vital Signs Monitoring (RVSM) with various sizes of the proposed MPA arrays at 60GHz for high detection accuracy and sensitivity, (iii) designing and tes~ing of MP As for 60GHz wireless local and personal area networks (WLAN/WP AN) in point-to-pint, point-to-multipoint and dual-band applications, (iv) implementation and testing of particular Partially Reflective Surface, Dielectric Lens and Defected Ground Structures on the proposed MP A designs with novel configurations at 60GHz for bandwidth and gain enhancement, and (v~ a comprehensive experimental study on the performance of large array designs with the proposed MP A elements for mm-wave applications. The mentioned research work is explained in the coming chapters in details. Moreover, all mentioned work has already been published