چكيده به لاتين
The new multilayered technologies, such as LTCC, has been giganic role in promoting multilayer structures in recent years. Multi-layered circuits increase the capacity of compressing and help to embedding multiple pieces in a module, and reduces overall system dimensions. In oscillators, with settel the resonator in blow layers, the total size of the circuit is reduced and radiation losses will be limited.
Oscillators play an important role in all telecommunications systems, and the phase noise generated by them is the fundamental noise in these systems. The basic difficulty in the design of oscillators with low phase noise in microwave frequencies is the poor resonator quality factor due to the high dielectric losses. By activating the passive resonators, the energy dissipated inside the resonator is compensated.
In this thesis, a multilayer circular SIW resonator with two new low losses and adjustable coupling coefficient, coupling structures is presented. To compensate the resonant loss, an amplifier is used in the resonator circuit. The feedback coupling coefficient is set to reduce the noise figure added to the system. The quality factor of new resonator is 1933 and noise figure equal to 6.14. Two oscillators based on active and passive resonators are designed and fabricated; both circuits use one type of amplifier with the same matching circuit. The phase noise of these each oscillators at 1 MHz frequency is 150 dBc/Hz and 133.6 dBc/Hz, respectively.
