Analysis of frequency diverse arrays for radar and communication applications

Çetintepe, Çağrı
Frequency diverse array (FDA) concept is one particular manifestation of waveform diversity, a topic which gains popularity among the research community in response to pressing demands of modern radar and communication systems such as multiple tasks, capacity and security. Introduction of a set of waveforms to the elements of an array, with slight shifts in the carrier frequencies so to establish frequency diversity, leads to far-field patterns that are remarkably different from conventional phased arrays, and opens up new possibilities like simultaneous missions, automatic beam scanning, range filtering, and flexible beamforming. Being a relatively new topic and lacking experimental demonstration in practical scenarios, the frequency diverse array concept lends itself to research opportunities from both theory and implementation perspectives. This thesis seizes these opportunities by proposing two possible applications for the FDA. First part of the thesis applies the FDA to a microwave link in a simple multipath propagation environment, establishes a theoretical framework to analyze its performance, and demonstrates potential improvement over a conventional phased array in mitigating harmful effects of multipath propagation. The second part then adapts the FDA to a monostatic radar configuration with a complex target, develops the theory to examine radar cross section (RCS) fluctuations as a function of target aspect, and shows more favorable RCS characteristics as an improvement over a conventional phased array. The thesis also encompasses experimental verification of these concepts with a practical FDA system. Measurement results obtained over a wide range of experimental parameters agree well with theoretical expectations.


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Yalım, Alper; Demir, Şimşek; Department of Electrical and Electronics Engineering (2013)
In this thesis, nine different methods aiming calibration of Phased Array Antenna (PAA) and Multifunctional Radars which employ PAA are presented. Those calibration methods are described, procedures of the methods are explained in detail, and information about constraints and measurement restrictions of those methods is given. As one step further, comprehensive work is focused on Multi-Element Phase Toggling (MEP) method and Rotating Element Vector (REV) method. Results of simulations are shown, theoretical...
Implementation of direction finding with frequency diverse array
Turhaner, Arsen; Demir, Şimşek; Department of Electrical and Electronics Engineering (2017)
Frequency Diverse Array (FDA) is a recent concept with lots of advantages that are emerged for the radar applications. In order to implement FDA practically, Linear Frequency Modulation (LFM) based FDA is recently offered. A tunable oscillator with delay lines is enough for the implementation. This novel design caught up the gaps of the FDA for a cheap implementation. In order to implement radar, there should be lots of features in the signal processing as well as in the RF front-end. One of the important f...
Development of PDMS-based micromachining process for microfluidic reconfigurable antennas /
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The objective of this thesis is to develop fabrication methods to implement microfluidic-based reconfigurable antennas. As the initial structure, a microfluidic based reconfigurable antenna is developed for transmitarrays, which consists of a multi-layered structure incorporating a microfluidic channel to confine liquid metal. The microfluidic channels are fabricated using soft lithography techniques where the channel material is PDMS. PDMS-to-glass and PDMS-to-PDMS bonding processes are optimized to achiev...
Implementation of an Enhanced Target Localization and Identification Algorithm on a Magnetic WSN
Baghaee, Sajjad; GÜRBÜZ, SEVGİ ZÜBEYDE; Uysal, Elif (2015-10-01)
Wireless sensor networks (WSNs) are ubiquitous in a wide range of applications requiring the monitoring of physical and environmental variables, such as target localization and identification. One of these applications is the sensing of ferromagnetic objects. In typical applications, the area to be monitored is typically large compared to the sensing radius of each magnetic sensor. On the other hand, the RF communication radii of WSN nodes are invariably larger than the sensing radii. This makes it economic...
Examination of Target RCS Characteristics in FDA Radars
Cetintepe, Cagri; Demir, Şimşek (2014-07-11)
This paper reports on the preliminary analysis of frequency diverse array (FDA) radars for simple target geometries. The radar system employs an FDA and a isotropic element as the transmitter and receiver antennas, respectively, and illuminates a target consisting of an arbitrary arrangement of ideal point scatterers. After establishing a signal model for the voltage waveform received by this radar system, the study then considers particular target arrangements and compares the average received power to tha...
Citation Formats
Ç. Çetintepe, “Analysis of frequency diverse arrays for radar and communication applications,” Ph.D. - Doctoral Program, Middle East Technical University, 2015.