Tommi Hariyadi

The design of microring resonators (MRRs) for serial configuration, integrated in the lateral scheme was presented and simulated using 3D electromagnetic simulator based on finite integration technique. The device model is embedded on the high index contrast (HIC) structure of silicon-on-insulator with monomodal cavity for TE-mode polarizations. From the proposed model, we varied the MRRs order, waveguides separation distance and ring radius, in order to evaluate the influence of those parameters on the device performance in terms of loss, free spectral range (FSR) and quality factor (Q-factor). Upon varying the gap distances, it was found that the highest Q-factor value of the proposed design was 1275 obtained at gap separation of 150 nm for ring radius of 6 μm, while the largest FSR was 24 nm. The trade-offs between device compactness, optical bandwidth and Q-factor are also presented

We present a design of a stepped-frequency surface penetrating radar for through-wall applications. The radar should work on 1500 – 3000 MHz, giving a total bandwidth 1500 MHz. The radar will have range resolution of 4,33 cm, maximum unambiguous distance 22,168 m, and the number frequency step is 512. Simulation with SystemVue confirms the implementability of the proposed design, both in the ideal and non-ideal conditions.

We present a design and simulation of broadband microstrip antenna with unidirectional radiation pattern for through walls radar application. Design and simulation with computer was confirmed the implementation of the proposed design. The results were validated by measurements in the laboratory. This research is a continuing from our previous research in developing antennas for through walls radar application. In previous research, we have developed a broadband microstrip antenna for through walls radar application in a bidirectional radiation pattern. Based on the laboratory experiment results, bidirectional radiation pattern still have weaknesses on detecting objects movement behind radar antenna. Unidirectional antenna has proven to have greater gain than bidirectional antenna. To obtain unidirectional radiation pattern antenna we added reflector behind the antenna to detect moving objects from in front of the antenna only. The previous bidirectional antenna for through walls application showed 4-5 dBi gain. In this research, the design and simulation of unidirectional antenna for through walls application showed 5.5 to 7.5 dBi gain. The unidirectional antenna will be printed using FR4 material with a dielectric constant and substrate thickness of 4.4 and 1.6 mm respectively. This antenna has a bandwidth of 1.5 GHz (66.67%) with frequency of 1.5 to 3 GHz.