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Textile antennas are currently being researched and developed so that they can be integrated into clothing. In this paper, two textile antennas with cotton and silk substrate are presented. The antennas operate at GPS L1 frequency, which is 1.575 GHz. This paper discusses the effect of antenna parameters on free space and on-body conditions, and the effect of antenna bending. Based on simulation and measurement results, the parameter values obtained indicate that the antenna can operate properly at a frequency of 1.575 GHz and is safe to use on the body.

One of the challenges of antenna development for wireless communication systems is to create an antenna that casn be operated in wide frequency so that a single antenna can be used in various wireless communication technologies. This paper discussed the wideband antenna with Telkom University Logo-shaped patch, using Fr-4 (?r = 4.3) substrate with 1.6 mm thickness. The antenna can be operated in the frequency range of 760 MHz – 13.75 GHz. The gain performance at the working frequency is still above 0 dBi. Hence, the antenna design to work properly for wireless communication systems which require relatively long distances. The Defected Ground Substrate (DGS) method is applied to achieve that bandwidth. Measurement shows the logo-shaped patch antenna achieves 12.994 GHz bandwidth with 1.33 VSWR and gain 2.85 at 921.5 MHz frequency.

The evolution of Wireless Body Area Network (WBAN) is made possible due to the rapid growth of wireless network and constant miniaturization of electrical devices. However, designing an antenna that is suitable for WBAN applications is challenging as the antenna should has compact size, in addition to the ability to endure low power loss during transmission and has robust communication link. Thus, a miniaturized wearable Dielectric Resonator Antenna (DRA) capable of radiating circularly polarized (CP) wave is designed. The antenna designing is done by using CST software. A total of 140 simulations is simulated in order to obtain the desired results. The DRA is used, together with conformal copper strips and miniaturized copper ground plane. The single point fed antenna is excited by a unique capital F-shaped conformal copper strips. The CP DRA offers a simulated Axial Ratio bandwidth below 3dB of ~23.85%, which is much greater than what has been reported in the previous work, with bandwidth of S11 below −10dB ~ 16.066%. In addition, the antenna designed in this research project managed to achieve an overlapped bandwidth of ~14.10% (6.9GHz – 7.94GHz). A prototype antenna is fabricated to validate the simulation result. Thus, the antenna design in this research will be helpful towards the evolution of the WBAN.

A 1×2 array microstrip patch antenna with defected groundplane structure (DGS) has been designed and simulated. This antenna design is intended for power harvesting application. Several simulation steps have been conducted such as simulating single microstrip antenna without DGS, then simulating single microstrip antenna with DGS, and simulating 1×2 array microstrip antenna without DGS. The last simulation yields wider bandwidth but the gain is still low. Antenna design still needs improvement to fulfill power harvesting requirements.

Pada penelitian ini, peningkat performansi antena mikrostrip MIMO dilakukan dengan menggunakan efek mutual coupling, maka dengan pencacatan bidang groundplane, atau yang biasa disebut dengan metode defected ground structure (DGS). Bentuk DGS yang digunakan adalah U-shape dan terbukti dapat mengurangi efek mutual coupling pada antena MIMO mencapai -22,833 dB dibandingkan dengan antena konvensional. Dengan menggunakan hingga 2 periodik, U-shape juga berhasil diperoleh pengurangan dimensi antena mencapai 29,89% dibandingkan dengan dimensi antena MIMO konvensional. Hal ini tentunya terbukti membuat metode DGS sesuai untuk digunakan pada antena dengan dimensi yang kecil dan mutual coupling yang baik pada massive MIMO pada aplikasi di perangkat portable. Kata Kunci: defected ground structure (DGS); antena mikrostrip; U-shape; mutual coupling

Recently the development of technology in telecommunications system, especially Digital Television (DTV), is growing very rapidly. In Indonesia, the adopted technology is Digital Video Broadcasting Terrestrial Second generation (DVB-T2) and has been utilized since 2012. It uses the UHF frequency range that is same with analog television. One device that is used to support DVB-T2 application is the antenna. It should inherit wide enough bandwidth as well as high gain to obtain good performance in receiving the DTV signal. In this paper, design of a linear triangular microstrip patch array antenna for DTV application is proposed. The design is adopting CPW-fed, parasitic patch and air gap methods to obtain wide bandwidth and relatively high gain. The proposed antenna has been fabricated and measured. The actual obtained bandwidth of this antenna is about 400.2 MHz. The value of VSWR, return loss and gain is of about 1.25, −18.79 dB, 3.21 dBi respectively, and has a unidirectional radiation pattern with elliptical polarization. The proposed antenna has been used to receive DTV signals and showed good results.

The e-CALLISTO system is a worldwide network that aims to observe solar radio emission for astronomical science. CALLISTO instruments have been deployed worldwide in various locations that together can provide continuous observation of the solar radio spectrum for 24 h per day year-round. Malaysia-UKM is a strategic equatorial location and can observe the Sun 12 h per day. This paper gives an overview of the spectrum allocation for radio astronomy, which falls in the specified operating frequency band of the CALLISTO spectrometer. The radio astronomy bands are analyzed at the Malaysia-UKM station according to the International Telecommunication Union recommendations. Some observational results are also presented in this paper.

Array antenna has been utilized in many radio telescope systems, especially for low frequency transient observation, to increase their resolving power. In this paper, a new method to determine the maximum resolving power of an array radio telescope based on the single antenna beamwidth is proposed. The method is derived from theoretical calculations combined with simulations. Statistical result shows that the equation inherits a standard error of 0.99, and hence is suitable to be used for rough calculation in determining an array maximum resolving power. It also can be used to estimate the maximum resolving power of an interferometer system with a slightly lower precision at very long baseline.

Dipole-based antenna has been widely used as the front end section of a radio telescope system, especially for low frequency observation. In this paper, a new method on designing dipole-based antenna for transient radio telescope system is presented. The method consists of three equations which were derived from statistical approach, by utilizing data from many antenna designs for different operating frequencies. Some of the designs have been constructed and measured, with frequency peak error down to 0.7%. These antennas have been utilized in some radio telescope systems, operated at National Space Center of Malaysia for solar monitoring.

Defected Ground Structure (DGS) has been introduced and used in developing microstrip patch antenna. DGS is implemented by etching off a shaped in the ground plane. In this paper, multi rings shaped DGS has been analyzed for WiMAX application at 3.65 GHz operating frequency. The effect on variation in the parameter study such us diameter of the rings, the width of each rings and introducing the gap on the ring the DGS antenna exhibits a reduction of 64.062% compared to the size of conventional antenna. The DGS method is suitable for mobile antenna application.

The Compound Astronomical Low-Cost Low-Frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) is a worldwide network of radio spectrometers designed for 24-hour solar observation. It is a collaboration among the Swiss Federal Institute of Technology Zurich and numerous local host institutes, spread out around the world. This paper presents an overview of the CALLISTO spectrometer system at the Universiti Kebangsaan Malaysia (UKM). The ?Malaysia-UKM? station is installed inside the campus area, at the Permata Pintar School building. In particular, this paper explains the details of the instrument's setup, and reports some of the data observed from this station. The realtime data are available from the e-CALLISTO International Network of Solar Radio Spectrometers.

Antenna miniaturization has become one important research, especially in mobile communication technology development. This paper presents the development of a miniaturized antenna for RFID application (924 MHz). Meandering technique has been adopted to create a geometrically small antenna relative to its operating frequency. Measurement result shows that the fabricated antenna inherits low return loss, down to -25.915 dB. The geometry of the antenna is 25.54 mm x 16 mm, which is much smaller than its resonance wavelength (0.079? x 0.049?). The measured gain is relatively small, of about -12 dBi. Nevertheless, the obtained parameters are acceptable since the antenna is meant for near field communication application.

Annular ring antenna concept has been utilized in many applications. This paper presents the adoption of annular ring concept on a dual-band microstrip antenna. The antenna is designed to operate at 1.9 GHz and 2.1 GHz operating frequencies. The objective of this research is to observe the method potential of combining two patches operate at different frequencies as a single dual-band antenna. While the purpose of the annular concept is to enhance the bandwidth of an antenna, analysis from this work shows that for a dual-band antenna with operating frequencies close one to the other, the obtained bandwidths are relatively narrow, down to of about 5%. Nevertheless, the antenna is capable to operate at both designated frequencies with good return losses down to -24.40dB.

Low-frequency radio astronomy has become a fascinating research area in the field of astronomy, including on its instrumentation development. In this paper, a multiband VHF antenna for low-frequency transient radio telescope is developed. The multiband has been achieved by combining V-shape half-wavelength dipole, traps, and parasitic elements. Measurement result shows that the antenna can work properly in three different frequencies designated by International Telecommunication Union (ITU) for radio astronomical purposes.

Antenna is one of the important subsystem components in a radio telescope system. In this paper, analysis on the effect of parasitic element on 408 MHz antenna in a radio telescope system is presented. Higher gain up to 10.24 dBi with reduction on beamwidth size has been achieved by optimizing the position of parasitic element relative to the driven element. The proposed antenna is suitable to be utilized in a transient radio telescope array.

The dipole-based antenna has been employed in many radio telescope systems. By utilizing this type of antenna, the possibility to conduct all sky monitoring and high spatial resolution observation in the same time can be provided. In this research, a new dipole-based antenna system will be developed for 21cm line observation. The dipole-based antenna is optimized in terms of standing wave ratio (SWR), gain and beamwidth. Initial results show a good achievement on SWR level, down to 1.005.

Dipole-based antenna has been used in many radio telescope systems, especially for low frequency astronomical observation. In this paper, analysis on beamwidth and gain of V-shape dipole-based antenna for different applications in radio astronomy observation is presented. Parameters to obtain wide and narrow field of view, up to 134°, down to 94°, are achieved with simple structures. Possibility to trade the beamwidth and gain off with higher sensitivity is also provided as low standing wave ratio down to 1.008 has been achieved. The results show different structures suitable for different applications in radio astronomy.

Design and development of antenna array for low frequency radio telescope has become one fascinating research in the field of Astronomy. In this research, optimization of two-element multiband antenna array for low-frequency transient radio telescope is presented. Narrow beamwidth down to 14 degrees has been achieved with maximum gain up to 12.31 dBi. The array is suitable to be used in a radio telescope system for solar and transient object monitoring.

Development of antenna for a radio telescope system has become a fascinating research area in the field of radio astronomy. In this paper, a design of compact multiband VHF antenna for a transient radio telescope system is proposed. The multiband has been achieved by combining V-shape half-wavelength dipole, traps and parasitic elements. Return losses of about −12.45 dB, −25.15 dB and −29.42 dB are obtained at three different frequencies, where the maximum gains are achieved at zenith direction for all operating frequencies. The proposed antenna is suitable to be used in a transient radio telescope which is operated in urban centers.