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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.

Cellular communication technology is experiencing rapid development with the arrival of 5G. This generation targets an increase in data rates and better capacity than the previous generation. MIMO is a technique that can be used to improve the performance of 5G communications. The frequency used this time is the middle frequency because it is considered more likely to be used as a 5G service frequency in Indonesia and has a larger coverage so as to save network development costs. In this study, the design and realization of a four-element MIMO antenna for 5G communication at a frequency of 3.5 GHz was carried out. The antenna used this time is a four-element MIMO antenna that has a monopole-based patch form which is then miniaturized so that the antenna has smaller dimensions. This design produces parameters, such as Return Loss on element one of -10.513 dB, for element two of -10.215 dB, for element three of -17.229 dB, and for element four of -14 dB. The value of element one is 1.84, element two is 1.31, element three is 1.31, and element four is 1.49. Bandwidth value ≥ 1500 MHz, and Mutual Coupling value ≤ -19.254 dB.

Kota Baru Parahyangan residential area, located in Padalarang sub-district of Bandung, has the quality and coverage of 3G and 4G cellular services that are not optimal, thus it has become a complaint of customers to the cellular providers. Therefore in this article a camouflage tower or Outdoor Distributed Antenna System (ODAS) is designed, which is a unique concept that helps in prividing connectivity in location where conventional tower construction is not permitted due to various regulations. This camouflage tower design aims to increase the number of cellular antennas but with minimal costs, land and human resources. In addition, this camouflage tower design has a high aesthetic value to be implemented in these elite residential areas. From the design and implementation results for 4G, the Reference Signal Received Power (RSRP) value is 70% at a value -90 dBm and Signal-to-Interference Noise Ratio (SINR) 70% at a value 5 dB according to the Key Performance Indicator (KPI) provider standard, while for 3G the Received Signal Code Power (RSCP) value is 70% at a value -78 dBm and Ec / No -12 dB. This shows that the quality and coverage both of 3G and 4G cellular services in this region have reached the target cellular providers.

One of the challenges of antenna development for wireless communication systems is to create an antenna that can 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.

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.

Filter is one of key module in a radio telescope system. This article present the development of VHF LC-passive filters meant to support a multiband antenna in a transient radio telescope system by reducing the bandwidth of each operating frequencies. The filters were developed by employing low-cost inductor and capacitor with low self-resonant frequency (SRF) an hence the characteristic are highly affected by the parasitic inductance of the capacitors an parasitic capacitance of the inductors. Therefore, general equation to develop an LC filters was no longer applicable in developing these filters. Nevertheless, three filters were successfully developed, operated at 38 MHz, 74 MHz and 152 MHz with relatively good quality factors up to of about 13.

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.