Varactor-based reactive network design for ESPAR phased array and antenna applications


Widespread adoption of phased array technologies has been hindered primarily by the high cost associated Transmitter/Receiver (T/R) modules. In conventional phased arrays, these vital elements often comprise up to fifty-percent of the entire array's expense. Recent development of a new type of phased array - the Electronically Steerable Passive Array Radiator (ESPAR) - is underway at laboratories around the globe. This innovative concept utilizes mutual coupling to excite neighboring (passive) elements placed in the near field of a center-driven (active) radiator. Using this method, T/R modules are only required for the active radiators. The radiation pattern of an ESP AR is controlled electronically by means of variable reactive loading of the passive antenna elements. In order to attain the full range of beam steering offered by this array, a broad range of reactance is required at the input port of each passive antenna. This thesis presents a varactor-based reactive network design that can accurately and reliably produce a wide range of reactance. The purpose of this research was to design a network compatible with the requirements of the ESP AR phased array, which is in development at the Antennas, RF, and Microwave Integrated Systems CARMI) laboratory at the University of Central Florida. To this end, an elaborate survey weighing different varactor-based reactive network and DC bias tee designs was conducted. This study took into account the practical issues and limiting factors that arose during design and implementation of such a network. While this specific network design was constrained to operate at 3 GHz, the proposed design methodology may be applied to realize reactive networks at other frequencies. This flexibility allows incorporation into similar ESPAR's and a plethora of other relevant devices.


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Thesis Completion





Gong, Xun


Bachelor of Science (B.S.)


College of Engineering and Computer Science

Degree Program

Electrical Engineering


Dissertations, Academic -- Engineering and Computer Science;Engineering and Computer Science -- Dissertations, Academic







Access Status

Open Access

Length of Campus-only Access


Document Type

Honors in the Major Thesis

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