Stability and Matching Techniques on Microwave Amplifier using Inhomogeneous Dielectric Resonator: Preliminary Study

Stability and matching techniques on microwave amplifier have been an important consideration to maintain the required performances, such as high power for the high-power amplifier and low noise for low noise amplifier. Simultaneously, the issues of the stability need more attention to avoid the presence of the oscillations. Typically, the stability factor and matching components of the microwave amplifier are frequency dependent. Thus, a frequency tunable mechanism is required to ascertain that frequency of the microwave amplifier resides within the stable region. The dielectric resonator is incorporated as the frequency tunable mechanism that implemented to overcome this issue. The characteristics of the dielectric resonator are evaluated on their physical parameter and material with different topologies of the parallel microstrip lines. This includes the spacing and curves configuration and the orientation of angular position for the dielectric resonator, especially for the multi-permittivity dielectric resonator. Regarding the preliminary study, the angular position of the multi-permittivity dielectric resonator does not influence the stability performances of microwaves amplifier, especially on the resonant frequency. The obtained best configuration of proposed dielectric resonator is consisting of 155-degree curves configuration with 19 mm spacing between the parallel microstrip lines for same waveguide port position. This configuration of the proposed dielectric resonator is incorporated as stability element and matching components that known as dielectric matching for conditional stable and unconditional stable transistors at 5 GHz.