Design of 2x2 Wide Bandwidth MIMO Antenna For LTE And 5G Sub-6GHz

In this study, the design of a 2X2 MIMO microstrip antenna was proposed for LTE and 5G Sub-6GHz applications. The antenna is designed to have a wide bandwidth operating in the frequency range of 2300 MHz to 3600 MHz. The antenna material uses FR4 substrate which has a dielectric constant of 4.6 and a thickness of 1.6 mm. To achieve a wide bandwidth, the ground length is cut. Meanwhile, to achieve the resonant frequency using the square slot method on the radiator element. Antenna design begins with designing a single element shape, then designing a 2x2 MIMO antenna. The results of the MIMO2x2 antenna simulation show that the reflection coefficient and isolation coefficient of each antenna are below -10 dB. The results of the reflection coefficient of each antenna show that the bandwidth achieved is more than 2 GHz. At a frequency of 2300 MHz, the lowest gain is 2.98 dBi, while the highest gain is 3.10 dBi. The lowest and highest gains at a frequency of 3600 MHz are 3.83 dBi and 3.87 dBi. Overall, this antenna has achieved the desired goal, which is to have a wide bandwidth and be able to operate on LTE and 5G applications

Realizing a 140\ua0GHz Gap Waveguide–Based Array Antenna by Low-Cost Injection Molding and Micromachining

This paper presents a novel micromachining process to fabricate a 140\ua0GHz planar antenna based on gap waveguide technology to be used in the next-generation backhauling links. The 140\ua0GHz planar array antenna consists of three layers, all of which have been fabricated using polymer-based microfabrication and injection molding. The 140\ua0GHz antenna has the potential to be used as an element in a bigger 3D array in a line-of-sight (LOS) multiple input multiple output (MIMO) configuration to boost the network capacity. In this work, we focus on the fabrication of a single antenna array element based on gap waveguide technology. Depending on the complexity of each antenna layer’s design, three different micromachining techniques, SU8 fabrication, polydimethylsiloxane (PDMS) molding, and injection molding of the polymer (OSTEMER), together with gold (Au) coating, have been utilized to fabricate a single 140\ua0GHz planar array antenna. The input reflection coefficient was measured to be below − 11\ua0dB over a 14% bandwidth from 132 to 152\ua0GHz, and the antenna gain was measured to be 31 dBi at 140\ua0GHz, both of which are in good agreement with the simulations

인체통신용 안테나에 관한 연구

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 남상욱.This thesis presents the antennas for in-body, on-body communication. The antennas in body communication are severely affected by human body which has a high relative permittivity and conductivity. The high relative permittivity and conductivity degrades the antenna bandwidth and efficiency. Therefore, it is a main challenge that enhancing the bandwidth and the efficiency of the antenna maintaining the small size. In order to enhance the performance of the antennas several techniques are proposed in body communication antennas. Firstly, the Q value and the efficiency of the in-body antenna are investigated. Using the proposed equations, the optimum frequency of the in-body antenna will be given. To maximize the antenna dimensions in the endoscopy antenna, the outer wall loop antennas is proposed. The measurement results are given to show the performance of the proposed antenna. Secondly, the several techniques for on-body antenna are proposed. The conventional antennas without the ground plane like dipole and slot antennas are not appropriate for on-body environment because the body has low intrinsic impedance and high conductivity compared to that of the free space. Therefore, antennas with ground plane like patch and cavity-backed slot antennas are proposed for on-body communication. The cavity-backed slot antenna with via-hole above the slot is proposed for bandwidth enhancement of the antenna. As the place of the via-hole introduces the additional resonance, wider bandwidth is achieved. The substrate removal technique for cavity-backed slot antenna is also proposed for the bandwidth and the efficiency enhancement. The removal of the substrate across the slot decreases the Q of the antenna, increasing the bandwidth and efficiency. In addition, the folded-cavity-backed slot antenna is given for size miniaturization of the cavity-backed slot antenna. The folded structure of the proposed antenna increases the effective length of the antenna, decreasing the antenna resonance frequency. Furthermore, the reconfigurable shorted patch antenna is given for wide bandwidth. Lastly, the dual-band and dual-impedance cavity-backed slot antennas are given for the efficient on-body systems1. Introduction 1 1.1 WBAN (Wireless Body Area Network) Applications 1 1.2 Electrical Properties of Human Body 5 1.3 Challenges in Designing Body Communication Antenna 7 2. Antennas in Human Body 10 2.1 Properties of the Antenna in Human Body 10 2.1.1 Radiation efficiency of the Antenna in Human Body 11 2.1.2 Q of the Antenna in Human Body 14 2.1.3 Numerical Results and Conclusion 15 2.2 Outer-Wall Loop Antenna for Capsule Endoscope System 18 2.2.1 Introduction 18 2.2.2 Antenna Design 20 2.2.3 Simulation and Measurement results 23 2.2.4 Conclusion 31 3. Antennas on human body 32 3.1 Properties of the Antenna on Human Body 32 3.1.1 Model of the Human Body 32 3.1.2 Antennas without Ground on Human Body 34 3.1.3 Antennas with Ground Plane on Human Body 36 3.2 Cavity-backed slot Antenna on Human Body 38 3.2.1 Operation of Cavity-backled Slot Antenna 38 3.2.2 Bandwidth and Efficiency Enhancement using Substrate Removal 40 3.2.3 Bandwidth Increase using Via-hole above the Slot 54 3.2.4 Miniaturization using Folded Cavity Structure 66 3.2.5 Dual-band Technique for Slot Antennas 81 3.2.6 Dual Impedance Cavity-backed Slot Antenna 86 3.3 Shorted Patch Antenna on Human Body 97 3.3.1 Operation of Shorted Patch Antenna 98 3.3.2 Reconfigurable Shorted Patch Antenna 100Docto

Low-power dual-band on-body antenna for wireless body sensor networks

In Wireless Body Area Network (WBAN), the implanted biosensor collects various physiological data and wirelessly transmits the information to external medical devices in real time. The antenna design for this application faces great challenges as the microwavepropagation medium is not the free space as the human tissues constitute part of the transmission channel. The effects of the human body should be taken into consideration during the antennadesign.The present thesis aims to arrive at the optimum design of the on-body antenna to operate as a central antenna for WBAN. Five types of helical antennas are proposed in the present thesishaving a dual-frequency operation at 2.45 GHz and 5.8 GHz. The proposed antennas are optimized to maximize the Signal-to-Noise-Ratio (SNR) and, hence, to minimize the BER and the Specific Absorption Rate (SAR) in the human tissues. In this thesis, a semi-analytic rigorous technique for the assessment of microwave propagation on the medium equivalent to the human body is developed and the radiated fields from the proposed on-body antennas in the near zone are evaluated.The commercially available CST® simulator is used and experimental measurements are done for the five fabricated prototypes. The near-field distribution over the surface of humanbody is evaluated at 2.45 GHz using a Matlab® program, while the far-field radiation patterns obtained by experimental measurements showing good agreement with those obtained by the CST® simulator. It is shown that the radiation patterns produced by the more compact antennas; the conical-helix monopole and the monopole-spiral antennas show better performance and moreappropriate for the intended application.It is clear from the obtained results that the conical-helix/monopole and the monopole-spiral antennas have the highest performance. These antennas are shown to achieve the minimum BERof 5.3 × 10-5 and 6× 10-8 for both antennas respectively. In addition, the minimum average of the SAR that does not exceed 0.3 W/Kg in the human tissues while consuming the minimum valueof the input power when compared with the other antenna types

Perancangan Antena Diplexing Menggunakan Metode Half Mode SIW dengan Metode Cavity Back Slot Sebagai Matching Impedansi

Penggunaan teknologi dinas tetap (fixed-services) bertujuan untuk memenuhi kebutuhan masyarakat akan teknologi telekomunikasi nirkabel. Pada perkembangannya muncul tantangan untuk meningkatkan performa dan efisiensi perangkat teknologi seperti penggunaan lebih dari satu frekuensi dalam satu device. Penelitian ini mendukung tantangan tersebut dengan membuat antena yang dapat bekerja untuk dua resonansi frekuensi (diplexing). Metode yang digunakan untuk mendesain antena diplexing tersebut yaitu Half Mode Substrate Integrated Waveguide (HMSIW) Cavity Backed Slot Antenna (CBSA). Metode CBSA mempunyai kemampuan untuk mencapai matching impedansi dengan mengatur inset-feed dan rectangular slot. Hasil simulasi menunjukan antena dapat bekerja pada frekuensi tengah (fC) 4,5 dan 5,8 GHz.  Nilai S11 dan S22 simulasi masing-masing memperoleh -30 dB dan -16,86 dB, serta nilai S12 dan S21 masing-masing -27 dB dan -26 dB. Sedangkan hasil pengukuran menunjukan antena bekerja pada frekuensi tengah (fC) 4,25 dan 5,67 GHz, dengan nilai S11 dan S22 masing-masing -33,10 dB dan -23,27 dB, serta nilai S12 dan S21 masing-masing -30 dB dan -29,6 dB. Hasil simulasi telah sesuai dengan spesifikasi yang diinginkan. Perbedaan dengan hasil pengukuran dapat disebabkan karena faktor pabrikasi, penyolderan dan proses etching