Harmonic suppression autenna for active integrated antenna

Abstract

The last breakthrough in the continuing miniaturization of electronics systems is made possible by the integration of circuit function and radiating elements into single module. Traditionally, electronic circuits and the antenna system have been designed by different groups of designers using different types of designs tools, working independently on either side of a well-defined interface, very often with very little interaction. This approach leads to separately packaged circuits and antenna subsystems, connected by cables and waveguides. Nowadays, the integration of circuits and antennas into single modules has been made possible by the common technological features of RF and microwave circuit and printed microstrip antennas. Active Integrated Antennas (AIAs) in which the active devices are integrated directly into antenna structure have been developed by the interest in the potential for sensor applications and spatial power combiner applications. With the advantages of no feed line losses especially at the high frequency, low power consumption, size and weight reduction, reliability enhancement, AIAs are getting much attention in the today’s wireless communication system. In AIAs the active nonlinear device can generate high level of harmonic radiations. Electromagnetic interference which is caused by harmonic radiations degrades the system performance. To overcome this problem, a band stop filter between active device and antenna can be used. But this technique increases the total size, insertion loss, and fabrication cost. A better way to solve this problem is to make a harmonic suppression antenna which can suppress harmonic radiations. In this thesis, first of all, the theory of microwave two-port oscillators, active integrated antenna oscillator, and harmonic suppression antenna, varactor diode are introduced. Secondly, a harmonic suppression antenna operating at the frequency of 4 GHz is proposed. The antenna used a T-shaped microstrip-line-f...