Propagation characterization of implantable antenna at UWB frequency – a review

A technology of wireless body area network (WBAN) was invented in order to enhance the quality of healthcare management as well as to determine faster disease prevention. However, to obtain the real-time data of images and videos from inside the human body, an implantable device is required. Currently, the Medical Implant Communication System (MICS) is used, but, this system has limited data rate which is a narrow-band of 402 – 405 MHz. Thus, this study on Ultra Wideband (UWB) for implanted device is conducted as UWB offers a wide transmission bandwidth as well as high data rate. Knowledge of radio wave propagation behaviour inside human body is needed to perform the implantation. Past researches related to this topic are limited and those conducted focused only on the human torso. This paper aims to provide a better understanding on the characteristics of radio wave propagation inside the human body by using an implantable device at UWB frequency. It is also hoped that this study could be used as reference for future research on this subject

Designing artificial magnetic conductor at 2.45 Ghz for metallic detection in RFID tag application

In this paper, three types of AMC with different shape and design is discussed. The single unit cell Halfring AMC designed in this paper had increased the bandwidth up to 9.46%. Parametric studies were conducted for those three AMCs to investigate the effect of varying the parameters of each design. The values of gain, directivity and return loss for all AMCs is discussed and compared. From the simulated result, when the dipole is attached on Perfect Electric Conductor, PEC the performance of antenna will drop severely. The new Halfring AMC designed in this paper had overcome the problem of metallic object detection in RFID tag application. The simulated result shows that the Halfring AMC at half-lambda size had increased the performance of dipole antenna with return loss = -22.60 dB, gain = 7.58 dB and directivity of 8.15 dBi

Single-band Zigzag Dipole Artificial Magnetic Conductor

A new Artificial Magnetic Conductor (AMC) structure called zigzag dipole is discussed. Based on the 0.92GHz straight dipole AMC, the zigzag dipole AMC operating at 0.92GHz, 2.45GHz and 5.8GHz are carried out using TLC-32 and RF-35 boards. This AMC structure is designed based on the characterization of a unit cell using a transient solver of Computer Simulation Technology (CST) software. The simulated results such as the reflection phase, reflection magnitude, surface impedance, bandgap and electric field for each single-band AMC are presented in this paper. From the results gained it shows that, the bandwidth of the AMC will increase when the frequency is increased. It is also proved that these AMC are not providing the bandgap at their resonance. The zigzag dipole AMC is carried out to minimize the AMC size and to be suitable for UHF RFID applications

Design of 0.92 Ghz artificial magnetic conductor for metal object detection in RFID tag application with little sensitivity to incidence of angle

In this paper, the new structure of Artificial Magnetic Conductor is presented. The AMC is designed to overcome the failure of detecting the RFID tag when placed near to the metal based object. It is too complicated to design an AMC at low frequency due to limitation of size and bandwidth. In this paper, the 0.92 GHz AMC is designed with different sizes and shapes of slots inserted into the square PEC patch. The size of single unit cell of this AMC is 45.5 mm x 45.5 mm. The AMC is designed in stacked layer to increase the bandwidth of single unit cell. The optimized AMC at 0.92 GHz frequency, had increase the performance of dipole antenna by return loss = -21.8 dB, gain = 3.0 4dB and directivity = 5.149

Design of a Broadband Microstrip Array Antenna for 5G Application

This paper presented a study that analyses the enhancement of high gain microstrip array antenna for 5G applications operating at 28 GHz designed to meet the ETSI standardization. It is expected that the gain must be high at high operating frequency so that it can compensate the propagation path loss. The objective of this study was to design a 16-element microstrip array antenna located at the top of antenna as a rectangular patch. Aiming to achieve low loss and high antenna efficiency, the material used for the proposed design was Roger 5880 materials with the permittivity of 2.2 and thickness of 0.25. Initially, a rectangular microstrip array antenna with 4 elements was designed. After analyzing the outcomes of antenna features such as reflected loss, efficiency and antenna gain, the 4 elements array were transformed into 8 elements array. To achieve high gain, it was then transformed into 16 elements array. Based on EM analysis using CST software, it was found that the proposed antenna has high efficiencies and high gain of 18.5 at 28 GHz operating frequency

IMPROVEMENT OF DIPOLE ANTENNA GAIN USING 8 CBU AMC-EBG AND 8 CBU FSS

This paper investigates the performances of dipole antenna incorporated with and without 8 CBU AMC-EBG and 8 CBU FSS at 5.8 GHz. The designs are simulated on Rogers RO 3010. Due to the flexibility of the material used as a substrate, the effect of a different angle is investigated. Both 8 CBU AMC-EBG and 8 CBU FSS act as reasonably good ground plane for the dipole antenna and help improving the realised gain and improve the radiation patterns by push the front lobe at the same time reduce the side lobes. The maximum improvements led by dipole antenna with 8 CBU AMC-EBG thus 8.543 dB of realised gain achieved and the front lobe is pushed higher and the side lobe is significantly lowered than with 8 CBU FSS. The designs of dipole antenna with 8 CBU AMC-EBG and 8 CBU FSS can be applied as high gain atenna for Intelligent Transport System (ITS)

Improvement Antenna Performance by using Artificial Magnetic Conductor at 28 GHz

The configurations of single patch antenna integrated with three different designs of patch artificial magnetic conductor (AMC) are presented in this paper in order to investigate the gain, radiation pattern, directivity and bandwidth of the antenna at a frequency of 28 GHz. Three cases of design configuration between patch antenna and three different designs of AMC are analyzed. First, configuration of patch antenna integrated with three designs of patch AMC. Second configuration of patch antenna integrated with non periodic patch AMC and third multilayer patch antenna with patch AMC. The details theory of the design configuration is explained. The simulated reflection coefficient and radiation pattern is presented. The simulated results showed that the gain, directivity and impedance bandwidth of all the design techniques are increased compared to patch antenna without AMC. For the first case, design of patch antenna integrated with design 1 AMC offer 13.96 % bandwidth and 12 % of the gain compared to patch antenna without AMC. In the second case, the overall size is reduced by 9.2 % and 14.14 % , respectively, compared with design in the first case. The third case of design structures provides more gain and bandwidth more than 3.57 %. In addition, the size is reduced compared to the previous two cases. Therefore, the result indicates the capability of this antenna integrated with AMC to be used for future 5G application. Index Terms: Artificia

Novel Artificial Magnetic Conductor for 5G Application

A design of novel bendable Artificial Magnetic Conductor (AMC) structures has been presented in this paper in two selected of frequencies at 5G application. These designs started with a square patch shape and continued with the combination of circular and Jerusalem shape which resonate at a frequency of 18 GHz and 28 GHz. Details of the theory and the structures of AMCs are explained. The reflection phase, bandwidth, angular stability and dispersion diagram were studied. The simulated results plotted that the novel AMC has good bandwidth and size is reduced by 53 % and 55 % for both frequencies. Other than that, it is also proved that the novel AMC has a stable reflection phase and no band gap performs at the specific frequency. The good performances of this novel AMC make it useful in order to improve antenna’s performanc

Spectrum Absorbency of Metamaterial Perfect Absorber

A triple-band metamaterial perfect absorber was introduced. The single meta-pattern based on gold-bar shaped was designed on the 0.02λ Taconic TLY-5. The gold-bar shaped was designed horizontal initially was then being rotated anti-clockwise from 0o to 90o to analyse and understand the variation of absorption spectrum. Dual band perfect metamaterial absorber was achieved at 45o. Then, the gold-bar shaped was slotted at both end to develop triple-band metamaterial perfect absorber. The slotted gold-bar shaped was evaluated three absorption peaks: 99.94%, 99.88% and 99.66% at 3.98 GHz, 4.81 GHz and 5.33 GHz, respectively. This however, shifted to the 3.96 GHz, 4.80 GHz and 5.33 GHz with absorbency 99.79%, 99.95% and 99.90% for the measured structure. Both simulated and measure results were achieved absorbency over 99% which was almost perfect absorption (≈100%). These properties are expected to be used in practical applications such as satellite and radar communications transmission. These properties of the metamaterial absorber could increase the functionality of the metamaterial absorber to be used in any application especially in reducing radar cross section for stealth application

Harmonic Suppression Rectangular Patch Antenna with Circularly Polarized

The rectangular patch antenna with proximity coupling at 2.45 GHz is designed and printed on FR-4 substrate with dielectric constant 4.3 and loss tangent 0.019. The overall size of proposed antenna gives 36 % reduction of substrate area as compared to conventional designs. The symmetrical arm of inverted U-stub and U-slot embedded on the transmission feed line suppress harmonic signal effectively at second and third order with minimum reflection coefficients of –0.51 dB and -2.28 dB respectively while circularly polarization was obtained by corner truncated and U-slot on the patch element. The return loss is -23.95 dB at fundamental modes with gain 4.61 dB and axial ratio of 1.48 dB