Phase characteristics of frequency diverse array radar: Phase radiation pattern, phase period, and phase centre

Deceptive jamming is a popular electronic countermeasure (ECM) technique that generates false targets to confuse opponent surveillance radars. This work presents a novel approach for hiding the actual target while producing multiple false targets at the same time against frequency diverse array (FDA) radar. For this purpose, the modified FDA radar is assumed to be mounted on the actual aircraft. It intercepts the opponent’s radar signals and transmits back to place nulls in the radiation pattern at the desired range and direction to exploit FDA radar’s range-dependent pattern nulling capability. The proposed deceptive jammer produces delayed versions of the intercepted signals to create false targets with multiple ranges to confuse the opponent’s radar system. The novel mathematical model is proposed whose effectiveness is verified through several simulation results for different numbers of ranges, directions, and antenna elements.

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Radiation-pattern control of Cassegrain antennas

IEE Proceedings H Microwaves Antennas and Propagation ◽

10.1049/ip-h-2.1987.0040 ◽

1987 ◽

Vol 134 (2) ◽

pp. 217 ◽

Cited By ~ 5

Author(s):

G.L. James

Keyword(s):

Radiation Pattern ◽

Pattern Control ◽

Cassegrain Antennas

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A hybrid neural network goal attain optimization for failed sensor(s) radiation pattern in linear array

Global Journal of Engineering and Technology Review Vol.4 (4) October-December. 2019 - Global Journal of Engineering and Technology Review ◽

10.35609/gjetr.2019.4.4(4) ◽

2019 ◽

Vol 4 (4) ◽

pp. 101-109

Author(s):

Navaamsini Boopalan ◽

Agileswari K. Ramasamy ◽

Farrukh Hafiz Nagi

Keyword(s):

Neural Network ◽

Radiation Pattern ◽

Array Signal Processing ◽

Linear Array ◽

Signal To Noise Ratio ◽

Beam Pattern ◽

Sensor Failure ◽

Signal To Noise ◽

Hybrid Neural Network ◽

Noise Ratio

Array sensors are widely used in various fields such as radar, wireless communications, autonomous vehicle applications, medical imaging, and astronomical observations fault diagnosis. Array signal processing is accomplished with a beam pattern which is produced by the signal's amplitude and phase at each element of array. The beam pattern can get rigorously distorted in case of failure of array element and effect its Signal to Noise Ratio (SNR) badly. This paper proposes on a Hybrid Neural Network layer weight Goal Attain Optimization (HNNGAO) method to generate a recovery beam pattern which closely resembles the original beam pattern with remaining elements in the array. The proposed HNNGAO method is compared with classic synthesize beam pattern goal attain method and failed beam pattern generated in MATLAB environment. The results obtained proves that the proposed HNNGAO method gives better SNR ratio with remaining working element in linear array compared to classic goal attain method alone. Keywords: Backpropagation; Feed-forward neural network; Goal attain; Neural networks; Radiation pattern; Sensor arrays; Sensor failure; Signal-to-Noise Ratio (SNR)

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Perbandingan Desain Antena Dipole dan Yagi-Uda Menggunakan Material Aluminium pada Frekuensi 470 – 890 MHz

JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI ◽

10.36722/sst.v3i3.219 ◽

2017 ◽

Vol 3 (3) ◽

pp. 140

Author(s):

Suci Rahmatia ◽

Putri Wulandari ◽

Nurul Khadiko ◽

Fitria Gani Sulistya

Keyword(s):

Radiation Pattern ◽

Daily Activity ◽

Dipole Antenna ◽

Antenna Gain ◽

Communication Tool ◽

Dipole Antennas ◽

Gain Bandwidth ◽

Large Gain ◽

At Home

Abstrak - Antena merupakan alat pemancar yang akrab dengan aktifitas sehari-hari dan mudah sekali dijumpai, di rumah, di gedung, bahkan pada alat komunikasi yang digunakan. Salah satu antena yang sering digunakan adalah antena televisi. Antena televisi yang sering digunakan adalah Yagi-Uda yang biasanya dipakai sebagai outdoor antena dan antena dipole yang biasanya digunakan untuk indoor antena. Masing – masing jenis antena memiliki kriteria dan keuntungan berdasarkan dari kebutuhan penggunaannya. Baik antena dipole maupun antena Yagi-Uda memiliki perbedaan diantaranya adalah besar bandwidth, nilai gain, dan pola radiasi. Pada paper ini dapat diketahui bahwa bandwidth yang dimiliki antena yagi-uda lebih besar daripada antena dipole yakni 0.39943 MHz untuk antena yagi-uda dan 0.16569 MHz untuk antena dipole. Begitupula dengan besar Gain yang dimiliki antena Yagi-Uda (6.64 dBi) lebih besar dibandingkan dengan gain dari antena dipole (2.29 dBi). Perbedaan ini dikarenakan faktor elemen director dan ketebalannya. Kata Kunci – Atena Televisi, Atena Yagi-Uda, Atena Dipole, Gain, Bandwidth Abstract - Antenna is a transmitter tool that is familiar with daily activity and easy to find at home, in the building, even on the communication tool used. One of antenna that is often used is a television antenna. Television antennas are often used is Yagi-Uda which is usually used as an outdoor antenna and dipole antenna that is usually used for indoor antennas. Each type of antenna has the criteria and advantages based on the needs of its use. Both dipole antennas and Yagi-Uda antennas have differences among them are bandwidth, gain, and radiation pattern. In this paper it can be seen that the bandwidth of yagi-uda antenna is bigger than dipole antenna that is 0.39943 MHz for Yagi-Uda antenna and 0.16569 MHz for dipole antenna. Neither the large Gain of the Yagi-Uda antenna (6.64 dBi) is greater than the gain of the dipole antenna (2.29 dBi). This difference is due to element factor of director and its thickness. Keywords – Television Antenna, Yagi-Uda Antenna, Dipole Antenna, Gain, Bandwidth

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