Now showing 1 - 2 of 2
  • Publication
    Cylindrical Dielectric Resonator as Dielectric Matching on Microwave Amplifier for the Unconditionally Stable and Conditionally Stable Transistor at 5 GHz Frequency
    Stability and matching techniques on microwave amplifier have been an important consideration to maintain their required performances, but typically its frequency dependent. Thus, a frequency variable mechanism is required. The dielectric matching employing the stability and matching techniques on microwave amplifier with cylindrical dielectric resonator has been investigated and realized. The cylindrical dielectric resonator (CDR) with parallel microstrip lines is proposed at 5 GHz frequency for unconditionally stable and conditionally stable transistor as dielectric matching. Hence, the proposed dielectric resonator with +2 mm spacing and 155Ëš of curved configuration indicated the best performances for preliminary study. The result improves the performance of the parallel inhomogeneous CDR by 9.77%. Subsequently, the homogeneous CDR is also successfully working as the variable frequency mechanism for unconditionally stable and conditionally stable transistor at 5 GHz frequency in maintaining their stability performances.
  • Publication
    Antenna Performance Enhancement using AMC Structure for 5G Frequency Range
    This paper presents a microstrip patch antenna operated at the fifth generation (5G) frequency range, which is at 3.5 GHz. To enhance the performance of the proposed antenna, an Artificial Magnetic Conductor (AMC) structure is implemented into the design. The 1x3 AMC is sandwiched between two FR-4 substrates and the performance of the proposed antenna is compared with the antenna without AMC structure. The simulated results prove that the proposed antenna offers better reflection coefficient with-50.45 dB compared to only-15.55 dB for the conventional antenna. Wider bandwidth is also achieved with 427 MHz of frequency bandwidth as opposed to only 135 MHz for the antenna without AMC. Besides that, the integration of AMC enhances the gain of the antenna when 3.7 dBi is achieved in contrast to only 3.21 dBi for the conventional antenna. Moreover, the efficiency of the antenna with AMC is also improved up to 68.54%. Furthermore, the ability to shrink 52.23% of the size of the antenna without AMC making it very favorable to be applied in 5G bands.