ECE Theses and Dissertations

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Browsing ECE Theses and Dissertations by Subject "Antenna measurements"

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    Picosecond Digital-to-Impulse (D2i) Radiators in Silicon
    (2014-11-24) Assefzadeh, Mahdi; Babakhani, Aydin; Kono, Junichiro; Mittleman, Daniel M
    Current techniques for terahertz (THz) time-domain spectroscopy (TDS) are based on femtosecond lasers and photoconductive antennas (PCAs). The PCA is the emitter and the detector of THz pulses and includes a THz antenna which is fabricated on a high mobility semiconductor substrate. THz-TDS techniques are used for 3D imaging and non-destructive evaluation of materials in pharmaceutical, medical and security applications. There are a number of limitations with current THz-TDS systems. Femtosecond lasers are expensive and bulky with high power consumption. They also require optical alignments. The delay line and object scanning are performed mechanically. The repetition rate and the radiated power are also limited. A single-chip impulse radiator in silicon can overcome these limitations. It is a high yield and low cost solution and can provide repetition rates of up to 10 GHz. A low power digital trigger is needed instead of an optical pump, without requiring lasers or optical alignments. In this work, direct digital-to-impulse (D2i) radiators are implemented in silicon technologies that can radiate sub-10psec impulses with on-chip antennas. System architecture, broadband phase-linear antenna design, circuit techniques, simulations and measurement results are discussed in this thesis. Also a full-system on-chip 4 by 4 array of D2i radiators are fabricated in silicon that provide beam-steering and spatial coherent combining of impulses.