Mujeeb Abdullah

Compact 4-port MIMO antenna system for 5G mobile terminal

A compact four-port multiple input multiple output (MIMO) antenna system is proposed operating in C-band at 3.5 GHz (3400 ∼ 3600) for future fifth generation 5G technology mobile broadband services. The four-port MIMO antenna system consist of an Inverted-L(IL)shape monopole on the edges of non-ground portion of 9×9 mm2 with substrate FR-4 and ground plane of dimensions of 136×68 mm2. The compact size of the MIMO antenna system is realized by using IL-shape shorted stripe and IL-shape slot etched in the ground plane to increase the electrical length of the IL-shape monopole for achieving the desired resonating frequency of 3.5 GHz. The antennas are placed orthogonally to each other results in reduce mutual coupling (less than −15 dB) with impendence bandwidth of 200 MHz for (S11≤-6 dB) and polarization and pattern diversity is also achieved.

A square slot circularly polarized microstrip antenna with enhanced bandwidth

A square slot circularly polarized (CP) microstrip antenna with enhanced bandwidth is presented. The proposed antenna consists of a C-shape patch and four rectangular strips around the four corners on the lower ground, and is excited by a microstrip feedline. A broadband CP antenna can be achieved by adjusting the size of the strips. The measured results of -10 db impedance bandwidth is 157.2% (2-16.7 GHz) and the measured 3 dB axial ratio(AR) bandwidth is 62.2% (8.2-15.7 GHz). Measured and simulated results show good agreement.

Compact four-port MIMO antenna system at 3.5 GHz

This work proposed a compact multiple-input multiple-output (MIMO) antenna system having four antennas each fed by coplanar waveguide (CPW) operating for 3.5GHz band (3400–3600) MHz. The proposed MIMO antenna system is realized with two groups of printed Inverted L-monopole of size 5×4 mm2 placed orthogonally to each other to attain the diversity capability of polarization and pattern at the edge of non-ground portion of size 15 × 15 mm2 of mobile handset. The proposed MIMO antenna system consists of four monopole inverted-L shape radiator each with parasitic shorted stripe extending from the ground plane having same dimensions. The parasitic inverted-L shorted striped served as tuning element by reducing the resonating frequency of the monopole radiator and improving the impedance matching. The mutual coupling between the closely packed antennas is addressed by the neutralization line by feeding anti-phase current to the neighbor antenna. The simulation result showed that that the impedance bandwidth at S11 ≤ −10 dB is 200 MHz enough for 5G network communication channel. The diversity parameters of interest are envelop correlation coefficient and mean effective gain are also calculated.

EIGHT-ELEMENT ANTENNA ARRAY AT 3.5 GHZ FOR MIMO WIRELESS APPLICATION

A multiple-input-multiple-output (MIMO) antenna array with eight printed coplanar waveguide (CPW)-fed monopole antennas operating at 3.5 GHz (3.4–3.6 GHz) is presented. Each antenna is an Inverted-L (IL) monopole surrounded by a parasitic IL-shorted stripe and attains compact configuration. Both the IL-monopole and parasitic IL-shorted stripe contribute their fundamental resonant modes to operate in the desired frequency band. The neutralization line (NL) and ground middle slot are used for decoupling the antenna elements in the array. The measurement results for the prototype reasonably agree with electromagnetic simulations. Measured results for the proposed MIMO antenna array demonstrate that it has impedance bandwidth more than 200 MHz with (S11 < 6 dB), and with effective antenna decoupling mechanism, the mutual coupling is better than 10 dB for the required band (3.4–3.6 GHz). Also, envelope correlation coefficient (ECC) for the proposed MIMO antenna array is less than 0.2 for any two antennas to realize independent prorogation path for a channel. The average channel capacity of the proposed MIMO antenna array is approximately 35 to 38 bps/Hz for a reference signal to noise ratio (SNR) of 20 dB.

Gain enhancement in cubic DRA with modified microstrip feed for WLAN applications

In this paper, a modified microstrip slot aperture feed is introduced which generates TEσ13 modes in a cubic dielectric resonator antenna resulting in a high gain (simulated = 10.5 dB and measured = 9 dB). The proposed feed can be realized by replacing the rectangular stub of microstrip slot aperture feed with a circular metallic stub of radius 3mm. The proposed feed excites the dielectric resonator antenna around a resonant frequency of 5.78GHz covering 5.725–5.850GHz WIFI band. The antenna exhibits an impedance bandwidth of 130.2MHz, and 135MHz in simulations and measurements respectively, and a stable gain throughout the 5.78GHz WIFI band with a maximum of 9 dB in measurements.

Compact dual-element printed monopole array at 2.6 GHz with application for MIMO terminal

A compact two-element antenna for multiple input multiple output (MIMO) system integrated in mobile handset operating for 2.6GHz or LTE-2600 is proposed. It consist of L-shape radiator and two folded L-Shape stripes extending from ground plane operating for mobile phone handset. The monopole itself resonates at a high frequency. The electrical length of monopole antenna can be increased by incorporating short stripes (Stripe_1 and Stripe_ 2) near L-Shape monopole. The coupling is helpful in improve impendence matching by reducing the inductive behavior for L-shape monopole. The Simulation results show the antenna performance meet necessary criteria for LTE 2600 or 2.6 GHz with average impedance bandwidth of 220 MHz, peak gain of 2.8 dB and total efficiency of 80 % and -11 dB isolation without using any decoupling network for two antenna structure.

Multiband wearable textile antenna for I.S.M body center communication systems

Wearable antenna utilization trend has been observed on raise due to its application for defense, medical and wireless communication devices. Most of portable electronic devices require multi-band compact antenna for operating for data and voice service. This paper presents the current state of art of the wearable antenna development, focusing on design and analysis issues. The investigation is focused on experimental characterization of multi-band miniaturized patch antenna using different electro textile substrate. The miniaturization is achieved by T-shape slot in the patch antenna and by using technique of mitering. By using technique of mitering extra part of metal is removed at the corner of the radiating patch resulting in reduction of capacitance and thus reducing the reflection coefficient as current null at the corner are removed. The antennas operating frequency consist of the industrial, scientific and medical (ISM) band from 2.45 GHz to 6 GHz Band of communication. The antenna performance was investigated by analyzing its reflection coefficient, VSWR, impendence bandwidth, and Specific Absorption Rate (SAR) for human blood. The simulation results show that there are various effects on bandwidth and frequency of operation as the structure of antenna is varied due to bending of radiating patch and flexible substrate.