Mashury Wahab

Small antenna using transmission line uniform for X-band navigation radar

In this research, a co-planar antenna with a small dimension is presented for vessel navigation radar. The radar, will be produced in a compact size so that it can be used at any type of vessels. The small antenna was fabricated on Duroid series 6006 with a permittivity value εr of 6.15. This enables a production of smaller antenna dimension, in comparison to the dimension of our antenna from the previous researches. The frequency center of the antenna is 9.4 GHz. The antenna will be implemented in a uniform configuration consisting of 16 modules for transmit and receive parts to achieve an equal phase. The simulated and measured results show similarity in performance. The overall antenna dimension is 40 cm × 0.27 cm, while it was 1600 cm × 10 cm in the previous design.

Antenna co-planar array of X-band frequency 9.4 GHz for radar

In this paper, carried out research on the development of radar antenna for X-band, with a resonant frequency of 9.4GHz. Antenna designed using coplanar array, the module is designed radiating patch of 4, 4 co-planar patch on the left side of the main and 4 co-planar on the right side of the main patch. Bandwidth resulting from the simulation is 677.8MHz, at a frequency of 9.0815GHz - 9.7953GHz. In the realization of Bandwidth is 419MHz. The resulting simulated VSWR at a frequency of 9.4GHz is 1.0256 and 1.056 for the realization of results. The resulting gain is 13.38dBi for simulation, and 14.1dBi for realization.

Development of phase inverter for performance improvement of FM-CW radar

In this paper, development of a phase inverter module for FM-CW (frequency modulated continuous wave) Radar is presented. The development is performed in the form of a design and simulation based on the theory of Samuel Y. Liao [2] and Tamasi Moyra et.als research for J mode phase inverter [6]. In a FM-CW Radar, two parallel separate antennas are used for transmitting and receiving signals simultaneously. Side lobes from both antennas are interfering with each other. This creates false detection at the receiver. To overcome this problem, a phase inverter is needed to remove interfering signals from the transmit antennas side lobes at the receiver. The phase inversion is performed for 180 degree phase shift (λ / 2) between the TX and RX signals. Experiments were conducted for developing phase inverter based on J, T, Y and # junction methods. Based on the calculations and simulations for the J-junction method, S11 of -22.2 dB and S14 of -43.475 dB (return loss), S12 of -4 dB and S13 of -3.34 dB (insertion loss output) were obtained, while phases S12 of 147° and S1 of -123°. For T-junction, S11 of -24.86 dB and S14 of -23 dB (return loss), S12 of -2.8 dB and S13 of -4.7 dB (insertion loss output) were obtained with phases S12 of 133° and S1 of -133°. Y-junction produces S11 of -25.86 dB and S14 of -25.989 dB (return loss), S12 of -3 dB and S13 of -5 dB (insertion loss output) with phases S12 of 65° and S1 of -23°. The #-junction creates S11 of -17.08 dB and S14 of -25.81 dB (return loss), S12 of -4.17 dB and S13 of -3.5 dB (insertion loss output) with phases S12 of 128° and S1 of -143°. Based on the results of designs and simulations, the phase inverting of 180° can be obtained more precisely by using the T- junction. The phase inverting using this T-junction achieves the best performance and will be implemented for our Radar antennas.

Performance evaluation of energy detector in Cooperative Spectrum Sensing

The main idea of Cooperative Spectrum Sensing (CSS) is to improve detection performance. Each Secondary User (SU) shares sensing information to collect data of the unused bands. One technique to detect those frequency bands is energy detector. This technique uses the threshold level to minimize spectrum sensing error in Cognitive Radio (CR) system. Proper selection of the threshold level results a good detection performance. In addition, detection performance to the unused spectrum is indirectly influenced by error rate. Less error rate in spectrum sensing leads to have a good detection performance. In this paper, the detection performance of CSS is investigated. The proper number of collaboration users with target error rate is determined as well in order to achieve an optimal performance. Total error rate of energy detector, signal to noise ratio (SNR), and number of CR user are used as metric for performance evaluation. Through computer simulation, numbers of CR user, degree of voting rule, and threshold value of energy detector have a significant impact to the achieved performance.

Design and realization of archimedes spiral antenna for Radar detector at 2–18 GHz frequencies

In this paper, a realization of archimedes spiral antenna for a Radar detector is presented, where this Radar detectors are used to detect Radar signal transmission within the frequency range of 2-18 GHz. In this research, an antenna was designed for the above information band. Multiple frequency bands covered by this antenna S band (2-4 GHz), C band (4-8 GHz), X band (8-12 GHz) and Ku band (12-18 GHz). The designed antenna has a shape of a spiral with a diameter of 5 cm. The antenna was implemented on a Roger Duroid 5880 substrate with εr = 2.2, thickness of 0.787 mm, and 1 oz for copper cladding. These spiral antennas have ultra wideband characteristics due to the planar structure and circular polarization with impedance of 188 Ohm. From the simulation results of the designed antenna, we obtained VSWR of 1.1 up to 1,27, a gain ranging from 3 to 6 dBi, with 3dB bandwidth of 61.7 degree. There is a similarity between the measurements and the simulation results. The realized antennas show advantages, e.g., VSWR <;2 and high gain, compared which the existing antennas in the market.

Radar radome and its design considerations

Radar plays a significant role in managing air and sea transportation, monitoring a certain areas, surveying, remote sensing, predicting weather, and defense. To protect the Radar against enviromental factors, a radome is required. In this paper, we present some design considerations for constructing a Radome. Based on experience in building the ISRA LIPI Radar, the Radome designs are presented. Measurement results on the effects of Radome to the Radar performance are also presented

Radar signal processing development for low probability of intercept radar system

In this paper, researches on the development of a low probability of intercept (LPI) radar is presented. This radar was developed based on the existing frequency modulated-continuous wave (FM-CW) coastal surveillance radar at the PPET-LIPI. This LPI radar development was initiated by modifying the antenna design to produce more perfect beams, where the beams determine the detection range to be achieved. The narrower the generated beam, the greater the detection range. The beam is set by adjusting the bandwidth, the smaller the bandwidth then the greater the detection range. Reflected signals from the targets will processed by the digital signal processing sub-system and its results are shown on the plan position indication (PPI) display.

Isolation improvement for x-band FMCW radar transmit and receive antennas

in this research, improvement on antenna isolation for frequency modulated continuous wave (FMCW) radar by adjusting side lobe level (SLL) and air gap distance is presented. The radar has two separate and parallel antennas: transmit and receive antennas. Low SLL will introduce high antenna isolation. For achieving a good performance, the required SLL is set to a minimum of 13 dB to produce high isolation and maximum reflection (echo) on the antenna main lobe. The Chebyshev method was applied for improving the main lobe efficiency, which is by modifying incoming power distribution on each patch. The patch shape was rectangular and this shape is modified by inserting slots to change polarization direction from vertical to horizontal polarization. Antenna feeding is performed by using the proximity method that aims to reduce radiation effect from transmission lines. This results in low interference to the main antenna radiation. The SLL for Chebyshev method is about −30dB and, for Uniform distribution, the SLL is about −13dB. The antenna development was started from defining its configuration, design and simulation, and finalized by optimization. From the simulation results, Chebyshev method gives low SLL and higher isolation in comparison to that of uniform method. For the Chebyshev antenna array with a distance of 9cm, the value of S12 equals −77.18048 dB and S21 equals −77.18053 dB. While for uniform antenna array with 13cm air gap, the S12 equals 75.864015 dB and S21 equals −75.86401dB. Lower values of S12 and S21 show higher antenna isolation. From the experiments, it was shown that the air gap distance is not linearly related to the isolation level. There is a certain distance where the optimum isolation value can be achieved. For the Chebyshev antenna array, it was shown that the simulation and measurement results are very similar.

Linear frequency modulation - continuous wave (LFM - CW) radar implementation using GNU radio and USRP

In this paper, the results of previous research on the beat frequency filter for the LFM-CW Radar is applied for the realization of GNU software into radio and applied on the USRP. The beat frequency components for distances of 10 km, 50 km and 70 km respectively were found around the frequencies of 66 kHz, 330 kHz, and 460 kHz. By using MATLAB simulation, the computed results are 66.67 kHz, 333.33 kHz, and 466.67 kHz. As it occurs in the observation of the targets, frequency components obtained from the frequency spectrum can be divided into two parts, namely, the negative frequency components and the positive frequency components, where one component of this frequency is a reflection of the other frequency components. Therefore, the negative frequency components can be ignored. By observing at the positive frequency components, our experiment shows that the frequency spectrum shape of the output of the WX GUI FFT block is already similar with the simulation results by using the MATLAB®.

Square notch ground plane binomial chebyshev for maximum main lobe frequency 9.3 GHz radar application

In this paper, was developed on how to increase the difference between the main lobe to the side lobe antenna, because if the side lobe antenna is very large, will lead to a huge influence on the performance of object detection by the main lobe. With side lobe magnitude would be no confusion, and detecting the wrong object. In this paper the authors do modification method development, by adding a notch on the side of the ground plane, resulting parameters are very nice and can be used in radar applications. With VSWR produced by 1,004, return loss of -54 dB, and the difference between the main lobe and the side lobe by 25, 74 dB. Designed antenna at a frequency of 9.27 GHz-9.33 GHz.