Herwansyah Lago

A Review of Antennas for Picosatellite Applications

Cube Satellite (CubeSat) technology is an attractive emerging alternative to conventional satellites in radio astronomy, earth observation, weather forecasting, space research, and communications. Its size, however, poses a more challenging restriction on the circuitry and components as they are expected to be closely spaced and very power efficient. One of the main components that will require careful design for CubeSats is their antennas, as they are needed to be lightweight, small in size, and compact or deployable for larger antennas. This paper presents a review of antennas suitable for picosatellite applications. An overview of the applications of picosatellites will first be explained, prior to a discussion on their antenna requirements. Material and antenna topologies which have been used will be subsequently discussed prior to the presentation of several deployable configurations. Finally, a perspective and future research work on CubeSat antennas will be discussed in the conclusion.

AMC-INTEGRATED RECONFIGURABLE BEAMFORMING FOLDED DIPOLE ANTENNA WITH PARASITIC AND RF MEMS

A beam-reconfigurable printed antenna on an Artificial Magnetic Conductor (AMC) is proposed for navigation and radiolocation applications at a frequency of 9.41 GHz. The AMC is formed based on a periodic Jerusalem cross shaped slot structure and is located in between two substrate layers, close to the radiator. The AMC plane has a bandwidth of 1.95 GHz around the targeted frequency of 9.41 GHz. By integrating micro-electro-mechanical system (MEMS) switches on the folded patches in combination with parasitic elements, a beam steering capability of up to ±58◦ is achieved with a rear full ground plane. This eliminates the need for a mechanical steering system, which is traditional in the applications targeted. The antenna achieves a high gain of 8.08 dBi and 90% efficiency. A good agreement between simulated and measured results is obtained.

A reconfigurable MEMS beam steering array (RMBSA) antenna for smart RADAR application

A reconfigurable MEMS beam steering array (RMBSA) antenna for smart radar application is proposed. The RMBSA antenna is designed with a coaxial probe technique as the medium to feed the current to the centre of the RMBSA antenna before the current is shared out to the radiating elements. This research successfully invented beam steering capability by using Micro-Electro-Mechanical System (MEMS) as an RF switch mechanism. The RF switches that implemented on the RMBSA antenna are without any additional circuit. This antenna design is potentially to steer in three different beam angles of -3°, 0° and 3° respectively. On the other hand, the proposed antenna also effective to maintain the gain in the range of 5.28 dB up to 5.39 dB at all capable angles on single operating frequency of 9.41 GHz. Dimension wise, 32.451 mm × 69.845 mm designed using FR4 with dielectric constant of □r= 4.7 as a substrate, the antenna is suitable to be implemented for a smart antenna system and radar in the future.

SAR for wearable antennas with AMC made using PDMS and textiles

Besides the radiation and reflection performance of wearable antennas, arguably one of the most important parameters is their Specific Absorption Rate (SAR). This work aims to evaluate SAR for wearable antennas integrated with Artificial Magnetic Conductor (AMC) plane made using different material categories — textiles and a flexible polymer,. Two types of textiles, felt and ShieldIt Super are used to build the first, textile-based antenna, while polydimethylsiloxane (PDMS) and the fluidic metal eutectic gallium indium alloy (EGaIn) are used to build the second, polymer-based antenna. Both materials are chosen due to their flexibility conformity to the human body, thus providing comfort to users. Despite the SAR for both antenna types did not exceed the European regulatory limits of 2 W/kg averaged over 10g of tissues; there are considerable differences between them.

Wideband textile antenna with low back radiation for wearable applications

A wideband textile planar antenna operating between the frequency of 2.06 GHz and 2.8 GHz based on the microstrip topology is presented. The antenna features a low back-radiation due to the existence of the full rear ground plane in the chosen microstrip topology. The intrinsic narrowband behavior of this topology is alleviated by the combination of several broadbanding techniques. The antenna indicated satisfactory performance in terms of reflection coefficients, gain/directivity and radiation patterns.

Gain enhancement of microstrip grid array antenna for 5G applications

A single patch microstrip grid array antenna is presented. The proposed antenna is designed in rectangular diamond shape with dimension of 34 mm × 35 mm in width and length respectively. Rogers 5880 with a low relative permittivity of 2.2 is used as substrate with the thickness of 0.508 mm. The proposed microstrip grid array antenna successfully enhanced the antenna gain up to 11.32 dBi compared to existing silicon dioxide antenna, 2.99 dBi and 10.35 dBi for existing stacked patch antenna arrays. The reflection coefficient, S11 is -24.08 dB at frequency of 28 GHz. With ease of fabrication and low-profile, the proposed antenna is potentially be implemented in future 5G applications.

A C-slotted dual band textile antenna for WBAN applications

A dual band C-shaped slotted textile antenna with artificial magnetic conductor (AMC) is investigated in this paper. The proposed antenna is operates in the 2.45 GHz (lower) frequency band for WBAN applications and in the 5.8 GHz (upper) frequency band for WLAN applications. A diamond-shaped AMC is used to improve the antenna performance and reduce backwards radiation for on-body usage. The proposed antenna is fully fabricated using textiles and utilizes felt as its substrate and ShieldIt Super as its conducting elements. Simulations and comparison against a same antenna without the AMC plane indicated that this conformal antenna operates with good reflection coefficients, gains, and radiation pattern within the desired bands.

A wearable textile dipole for search and rescue application

A wearable textile antenna for search and rescue application is presented in this work. It is designed based on the dipole topology to operate at 406 MHz for the Cospas-Sarsat application and fabricated fully using textile materials. The meanderline miniaturization technique is chosen to compact the proposed dipole due to its expected large size and wavelength at 406 MHz. The antenna evaluated in planar and bent forms indicated satisfactory performance when evaluated in terms of reflection coefficients, gain and radiation patterns.

A flexible deployable CubeSat antenna

This paper describes the design procedure of a deployable antenna for Cubesat applications operating in the UHF frequency band of 437 MHz. Due to the expected large size for operation in this band, the meanderline and Vivaldi miniaturization and broadbanding techniques are used to obtain a wider impedance bandwidth. This is to ensure the size compatibility of the proposed antenna to the compact Cubesat chassis, and to ensure operation with different orientations in space. The antenna is designed using CST Microwave Studio software, and is aimed to be integrated with the RF components in the Cubesat platform. The antenna is capable of operating in the 437 MHz band with a 10 dB impedance bandwidth of 5% and a gain of 4.1dBi.

Effects of hand on the performance of 5 GHz two-port terminal antennas

Influence of hand on the MIMO antenna performance for future 5G terminal has been studied and presented in this paper. The study covers on performance for mobile terminal operating at 5.0 GHz with 1 GHz bandwidth at −6 dB. Development of this study is due to the concern from service provider and mobile designer in developing a small and compact mobile terminal. The effect of users finger is studied on sixteen index finger locations. Depends on the location of the index finger, the reflection coefficient and mutual coupling are deteriorated, whereas radiation and mismatch efficiency losses are increased. It is shown that the losses of radiation and mismatch efficiencies can be up to −1.6 dB and −0.9 dB respectively.