Hussam Al-Saedi

A Dual-Band Printed Antenna Design Based on Annular Koch Snowflake Slot Structure

The design of a fractal based slot antenna, to serve the dual-band communication applications, is proposed in this paper. The structure of the proposed antenna is based on the Koch snowflake fractal geometry of the third iteration as applied to the outer and inner perimeters of an annular ring slot configuration. The antenna slot structure has been etched on one side of a substrate representing its ground plane, and a microstrip line feed is printed on the other side. The realized results proved that the proposed antenna could excite three resonant modes. The first one was assigned for the lower resonating band from (2.24–2.93) GHz, while the second and third modes have been merged forcibly to generate the upper resonating band from (4.48–5.54) GHz. In terms of the guided wavelength, λg, the resulting antenna has a compact size of 0.57λg × 0.57λg. The results reveal that the antenna yields two resonant bands with a significant extent of the frequency ratio. To improve the antenna performance at the two resonant bands, investigation of current density distributed on the surface of the antenna is conducted at selected frequencies within the swept range. With the aid of this study, it has been found that when applying a defected ground structure (DGS) on the antenna ground plane, it can be considered as a tuning means of the two resonant bands. Measured results carried out on two fabricated prototypes confirm those theoretically predicted.

Space division multiplexing using disordered optical antennas

Using disordered highly coupled nanoantennas, previously we proposed a novel scheme for optical information multiplexing [1]. It was shown that for a given random configuration of nanoantennas, orthogonal transmission channels can be identified and realized. It is desired to increase the number of channels for a given configuration. Here we investigate this in more details.

A wide axial ratio beamwidth circularly polarized antenna for Ka-band satellite on the move (SOTM) phased array applications

A wide axial ratio beamwidth circularly polarized (CP) antenna based on aperture-coupled elliptical microstrip patch antenna fed by a GCPW line is presented as a building element for a large-scale Ka-band SOTM phased array. The proposed antenna element is developed with a low-cost PCB planar technology. Full wave solver from ANSYS is used to optimize and evaluate the antenna performance. The simulated return loss bandwidth 31% centered at 31 GHz. Moreover, the proposed antenna element shows a 3 dB axial ratio (AR) bandwidth 3.4% centered 29.6 GHz in all φ angles and ±80° from boresight.

E-plane RWG-to-SIW Transition Power Splitter for Ka-Band SATCOM Application

A transition power splitter, consisting of metallic rectangular waveguide and substrate integrated waveguide, is presented for large-scale millimeter-wave antenna array systems. The power is coupled between the RWG and the SIW through two centre-slot transition, one etched on the SIW ground plane and the other cut through metallic RWG narrow side wall. The 3-dB RWG-SIW (T-junction) transition splitter was designed and simulated by the HFSS full-wave solver. The simulated S-parameters of the splitter is presented, showing a return loss (RL) better than 10 dB and insertion loss (IL) are better than 0.60 dB.

A broadband siw-integrated circular polarized antenna

A circularly polarized (CP) substrate integrated waveguide (SIW), made of two integrated linear polarized (LP) microstrip patch antennas (MPA) is presented. The antenna has high radiation efficiency and wide CP radiation bandwidth. The antenna uses a 3dB-SIW splitter/combiner to generate CP field from two LP antennas. The structure was designed, and simulated by using two EM full-wave solvers; HFSS and CST over the frequency band 50–70 GHz. Highly rigorous simulations were performed. Simulation results reveal that the antennas show 3dB axial-ratio (AR) bandwidths over the frequency band ∼ 57.80–68 GHz with average CP gains ∼ 7 dBic.

DRA array fed by folded SIW feeding network

This paper presents a two dimensional (2D) dielectric resonator antenna (DRA) array fed by a folded substrate integrated waveguide (SIW) feeding network. By integrating the SIW feeding network in two dielectric layers, the antenna array becomes compact and low profile which is suitable for portable millimeter wave applications. The antenna array with the folded feeding network is studied numerically. The simulated results show that the proposed antenna achieves a 10 dB impedance bandwidth covering the band 35.6-37.4 GHz with peak gain of more than 22 dB and radiation efficiency of 80~86%.

SIW-integrated patch antenna backed air-filled cavity for 5G MMW appilcations

This paper compares two different SIW-integrated high gain patch antennas operating at Ka-band. Each design configuration shows a different linear polarized (LP) radiation, vertical or horizontal. The gain enhancement and polarization are controlled by the integrated SIW cavity and the excitation slot orientation, respectively. The simulated results for reflection coefficient, gain and radiation pattern are presented. The antennas show a 5 dB gain enhancement for both polarizations over the operating frequency bands 54.9-64 GHz, and 50.20-65.80 GHz.

A dual circularly polarized patch antenna for broadband millimeter wave (MMW) communication systems

An aperture coupled circular patch antenna is presented for dual circular polarization at Ka-band. Two microstrip lines are used to excite a circular patch through two slots to generate a broadband RHCP and LHCP radiation with high isolation between them. An aperture coupling is employed to provide a wide beamwidth axial ratio. The proposed antenna is a good element candidate to be considered for compact polarization reconfigurable phased array antennas. The simulated results of the presented antenna show a10 dB impedance bandwidth of more than 15.1% with very good isolation bandwidth. Furthermore, it shows a 3 dB axial-ratio of 13.9% at 30 GHz. Additionally, it acquires an axial ratio less than 3 dB over ± 50. beamwidth for 2.2 GHz bandwidth.

SIW series-fed patch antenna array based on transverse slot excitation for millimeter wave (MMW) applications

A two-element patch antenna is excited by a transverse slot cut on the substrate integrated wave-guide top plane is presented. It is then used as a building block to form a linear array of 4 elements at mm-wave band. The proposed design is compact, low profile, and efficient. Additionally, it has high F/B ratio and high linear polarization purity. The simulation results of 1×4 array shows an operating impedance bandwidth of 1.6 GHz centered at 30 GHz with 14.5 dB gain and more than 85% radiation efficiency. Furthermore, the F/B ratio is 25 dB with very high cross polarization discrimination better than 60 dB.

Design and analysis of reconfigurable reflectarray antennas for Ka-band satellite communications on the move

A scanned beam reflectarray antenna (RA) is theoretically designed and analyzed for Ka-band satellite communications on the move (SOTM). A general theoretical approach is developed where the effect of mutual couplings between elements of the array is reasonably considered, resulting in a good prediction of antenna radiation characteristics. The designed reflectarray is constructed with a new broadband and low loss unit cell (UC). Some of the primary achievements are presented, showing pattern gain loss better than -4.8 dB, cross polarization level less than -10 dB (worse cases are in ±45° inter-cardinal planes), and side lobe level less than -27 dB for scanned angles up to ±60° from broadside in whole azimuth area.