Yana Taryana

Modified sierpinski patch antenna with co-planar waveguide feed for multiband wireless applications

In this paper, a modified fractal sierpinski patch antenna suitable for multiband wireless application is proposed. Various heights of a triangle component in sierpinski antenna are compared to achieve the desired resonant frequencies and then a coplanar wave guide feed is used to achieve more multiband resonant frequencies within 0-7 GHz frequency range. Return loss characteristics suggest that the antenna is suitable for WLAN, Wimax and also GSM bands for VSWR<;2. Bandwidth measurement based on VSWR=2 for 900 MHz is 245 MHz, at 2.4 GHz is 620 MHz, at 3.3 GHz is 1020 MHz , and for 5.8 GHz is 400 MHz.

Combine non simultaneous conjugate match and simultaneous conjugate match techniques for X-band LNA design

This paper studies the design of low noise amplifier (LNA) by using combining non simultaneous conjugate match and simultaneous conjugate match technique. The purpose of such combining technique is to obtain trade off minimum noise figure, minimum voltage standing wave ratio (VSWR) and high gain. In the design process, two stage configurations are applied. The first stage uses non simultaneous conjugate match (Non SCM) technique and the second one uses simultaneous conjugate match (SCM) technique. This work uses BJT transistors of BFP 840ESD and the rogers RO4003C substrate as planar structure for matching impedances network. The Agilent Design System (ADS) software is used to obtain LNA characteristics. The designed LNA at frequency 9.3 GHz achieves gain 28.01 dB, noise figure 1.57 dB, VSWR input and VSWR output are derived at values 1.17 and 1.28, respectively.

Four port diversity patch antennas for MIMO WLAN application

A four port diversity microstrip patch antennas for WLAN was designed, working in the 5.180 to 5.220 GHz frequency. Port diversity was carried out by changing the orientation of the port as of 90° between each consecutive port to reduce mutual coupling and reduce overall dimensions of the antenna. Dimension of realized antenna was 49.48 mm × 49.48 mm. All antenna element has VSWR ≤ 1.5 and mutual coupling ≤ −20 dB. Bandwidth of the antenna 1 to 4 was 92, 96, 68, and 83 MHz respectively. The resulting gain antenna 1 to 4 was 3.306, 3.428, 3.38, and 3.315 dBi respectively. The antenna had unidirectional radiation pattern with elliptical polarization.

S-band two stage low-noise-amplifier using single stub matching network

Two-stage low-noise-amplifier (LNA) using single stub matching networks for S-band operation is proposed, designed, and developed. The configuration aims to obtain high gain amplifier with minimum voltage standing wave ratio (VSWR). The proposed LNA consists of the first and the second stages using hetero junction FET NE3509M04 as active device where it has high associated gain. The proposed LNA is designed with planar structure on a Rogers RO4003C substrate. The planar structure is also used for obtaining good matching condition. The Agilent Design System (ADS) 2011.10 software is used for analysis of gain, VSWR, noise figure (NF) values and impedances. Characterizations of the designed LNA at 3 GHz are 1.71 of VSWRin, 3.07 of VSWRout, 6.17 dB of NF and 23.71 dB for gain which is lower 8.66 dB than simulated result.

Double stage Low Noise Amplifier at 1.27 GHz for Synthetic Aperture Radar application

Synthetic Aperture Radar (SAR) is radar technology for remote sensing which transmits electromagnetic pulse to earth where the pulse is reflected back to SAR and received by antenna receiver. The received signal is very low, it should be amplified by Low Noise Amplifier (LNA). To satisfy the SAR system, this paper propose to design a double stage LNA which operate at 1.27 GHz. In the design process, it used active component BJT Transistor of BFP 640 for the both stage. While to achieve the impedance matching condition is deployed on an FR4 substrate which has 4.6 of dielectric permittivity. The Advanced Design System (ADS) is applied to determine gain, voltage standing wave ratio (VSWR), and noise figure (NF) as LNA characterization. The simulation results at 1.27 GHz recorded 42.10 dB of gain, 1.87 of NF, while input VSWR and output VSWR are 1.15 and 1.25 respectively.

Magnetic and microwave absorbing properties of Al and Zn substituted barium hexaferrites in X-band region

In this study, the Al and Zn substituted barium hexaferites with x = 0, 0.5, and 1 were prepared using wet mechanical alloying along with calcination at 1200°C and sintering at 1250°C. X-ray diffraction (XRD) characterization shows that single phase of M-type barium hexaferrites are formed in substitution amount x 0 and 0.5, and there are W-type barium hexaferrites peaks detected at x = 1. The addition of AlZn decrease the coercivity from 1.721 to 0.986 kOe at x = 0 and 1 respectively. Increasing the composition from x = 0.5 to x = 1 also reduce the magnetization saturation significantly. The microwave absorption of the prepared AlZn substituted barium hexaferrites with thickness 2 mm in X-band region is still relatively low, the maximum return loss is achieved when substitution amount x is 1 with value of 12.2 dB at 10.5 GHz. Increasing the substitution amount x of AlZn from 0 to 1 only slightly increases the value of return loss and shifts to lower frequencies.

Performance enhancement of microstrip patch antenna by incorporating exponential-square patch model

A microstrip exponential-square patch antenna have been proposed and simulated in this paper. It consists of an exponential-square patch, a substrate, a square ground plane and probe feed. The exponential-square patch shape is modified from conventional square geometry with two parallel side replaced by two exponential curve. From simulation results, it is shown that microstrip exponential-square patch antenna has wider bandwidth, lower return loss, higher gain, within same radiation pattern and same beam width compared to conventional microstrip square patch antenna. The proposed antenna is designed and simulated at 3 GHz frequency operation suitable for S-Band radar application.