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Regardless of the bandwidth of reflectarray (RA) elements, the RA bandwidth is narrower for many possible reasons. For a RA with small f/D, the ray path length varies as we move away from the center, which is compensated by the elements that are designed at the center frequency. However, as the frequency changes, the path length phase errors grows, as we move away from the center, at a more rapid...
This paper proposes a new unit cell for C-band circularly polarized reconfigurable reflectarray antennas. In order to obtain the desired beam pattern for the antenna, a variable rotation technique which allows a proper phase control in the array and enables full 360 degree phase adjustment in the bandwidth is implemented. Circular rings are used as reflectarray elements instead of electronic devices...
For mounting antennas on a thin (ka∼0.5) cylindrical platform, new designs are required. In this paper, a conformal Planar Inverted-F Antenna (PIFA) for mounting on such a cylinder is presented. The PIFA configuration is low cost and easily fabricated. Simulations indicate a −10dB impedance bandwidth of 16%. This new design is a good candidate for antennas for wireless communications and navigation...
We present our latest advances in antenna miniaturization using dielectric resonators and design of sparse arrays for ultra-wide band applications without the need for non-linear numerical optimization. We experimentally demonstrate a dual-feed, low-profile, stacked dielectric resonator antenna for the C band with wide bandwidth and high gain, as well as a bio-inspired sparse array design for ultra-wide...
This paper proposes a high-gain mechanically reconfigurable antenna array based on a ring-shaped slotted-waveguide antenna for mm-wave applications. A full scanning range in the azimuthal plane is ensured by proper mechanically rotating a metallic jacket, which partially covers the array radiating structure. The technique provides a beamwidth of 37° in the azimuth plane and gain of 17.41 dBi at the...
This work reports the development of antennas and antenna arrays for the future 5G cellular networks, which have been realized at the Brazilian Institute of Telecommunications (Inatel) in the last four years. Diverse reconfigurable antenna types based on printed and milled structures have been designed, fabricated and proper characterized from microwaves to mm-waves, with the aim of fulfilling the...
Ku band shaped pattern fan beam high gain spaced-borne slotted waveguide array is optimized and analyzed. The total array is composed by 16 partitions. Half height waveguides are used to reduce the slotted waveguide array weight. The waveguide wall thickness, coupling among the slots, circle end slots and other factors are all taken into account during the design process. The total array is fastened...
In this paper Compaq patch antenna is designed using array of E shape element and its performance is optimized using defected ground structure. Two array designs are proposed of 1 by 2 elements and 2 by 2 elements and its performances are analyzed. Circular DGS is introduced to enhance the performance characteristics like gain, bandwidth, mutual coupling and better isolation between elements of antenna...
Millimeter wave (mmWave) communication has been a key technology for the fifth generation (5G) wireless communications. There have been various mmWave channel measurements. However, many measurements in the literature are conducted with different configurations, which may have large impacts on the propagation channel characteristics, and make the comparison of propagation channel characteristics for...
Modern transmitter architectures make use of multi-input multi-output (MIMO) techniques, employing a high number of RF power amplifiers (PAs) to excite an antenna array. The array elements are often coupled, creating an excitation at the output of the PAs, which is dependent on the outputs of the other elements. Therefore, in this system, the nonlinear behavior of each PA cannot be fully described...
This paper presents simulation results of a dual-polarized 2×2 element sub-array antenna element at 15 GHz center frequency. The basic idea is to use two waveguides stacked on in a right-angle configuration to excite the orthogonal polarizations by using radiating slots. Above the slots, 4 parasitic patches are set to a form of 2×2 element sub-array. Antenna presents −10 dB impedance bandwidth from...
Millimeter wave (mm-wave) bands are becoming potentially attractive candidates for next generation communication systems. It is envisioned that high gain smart antennas will be one of the key enabling technologies for such systems. At mm-wave bands, where electrical size of an individual antenna becomes very small, the inclusion of a reconfigurable mechanism in the antenna becomes a great challenge...
A dual-polarized wideband substrate-integrated-waveguide fed aperture-coupled slot antenna array for 60 GHz is proposed. By cutting a semicircle shape on the edge of the crossed-slot antenna, the impedance bandwidth of the proposed antenna is effectively widen and achieves overlapped bandwidth of 16.7% for simulated |S11| and |S22|. In addition, over 35 dB isolation between two polarization and low...
In this paper, an ultra-wideband (UWB), wide-scan tightly coupled dipole array (TCDA) is designed. The dipole elements and the integrated baluns are printed on a vertical printed circuit board (PCB) backed with a ground plane. Two wide-angle impedance matching (WAIM) layers over the array aperture are used to achieve broadband and wide-angle scanning. The antenna is excited by a coaxial line with...
Millimeter-wave (mm-Wave) Massive Multiple Input Multiple Output (MIMO) at 60 GHz is a candidate of advanced wireless communications for indoor environment. Mm-Wave massive MIMO antenna with lower frequency with sectoring technique has been proposed in previous research. Also dual polarized configuration for MIMO in lower frequency and lower number of antenna. Massive MIMO at 60 GHz mm-Wave is not...
In this article, a compact MIMO dual-band (2.6/3.6 GHz) antenna array for future 5G handsets is presented. The antenna element has a compact with size of 10.5×14.5 mm2. The proposed antenna array elements are symmetrically placed along the long edges of the smartphone, and they are composed of four same antenna types. The reference element antenna consists of U Shape structure and a connected meandered...
Millimeter-wave antennas are one of the key parts in 5G systems due to its useful properties such as ultra wideband and high transmission rate. In this paper, the research of microstrip millimeter wave patch antenna at 28 GHz is proposed. The resonant frequency of microstrip antenna is shifted to the expanding bandwidth through slotting the patch. Meanwhile, adding punish function to fitness function...
A conventional symmetric Zig-zag antenna is improved by adding a shunt shaped dipole at the feeding terminals or a shaped dipole as parasitic reflector, this dipole results in an increment of radiated gain in forward direction while remaining the wider frequency bandwidth of Zig-zag antenna. By means of the method of moments with piecewise-sine bases and Galerkin's procedure, the Zig-zag structure...
This paper introduces a broadband conductor-backed coplanar waveguide (CBCPW) to double-sided parallel strip line (DSPSL) transition structure. The performance is demonstrated in a back-to-back (B2B) configuration on 0.127 mm thick FR408 with relative permittivity of 3.75 and loss tangent of 0.018. AWR AXIEM and ANSYS HFSS simulations have been used to optimize all the structures. Simulation and measurement...
A 0.5–3GHz true-time delay (TTD) phase shifter circuit is implemented. Basing on active delay cells and active switches, the coarse delay is achieved. The LC artificial transmission line (ATL) provides continuous delay. The delay variation of the total delay is less than 2.4%. Using broadband matching and shunt peaking techniques, larger bandwidth and flatter group delay is obtained in phase shifter...
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