The superiorities of microwave heating technology have attracted many researchers for further development. Designing a satisfying temperature control system for the microwave system is one of them. To confirm that the controller can work with good system performance, the adjustment of controller parameters is important. Most previous research about microwave control systems did not focus on the tuning problem which is presented in this work. This paper provides the use of a genetic algorithm to adjust the best parameters for a PID controller. A microwave heating system with a single microwave power input and a single output temperature probe which is identified using the ARX model is examined. Evaluation of the proposed controller was conducted in the simulation environment using MATLAB. The result shows that the genetic algorithm can obtain the most optimized parameter for PID controller which can follow a certain heating pattern. The parameters for Kp, Ki, and Kd are 998.94, 79.42, and 79.78, respectively. It can minimize the value of integral absolute error for the given setpoint to 446.11.

Microwave absorber able to inhibit the reflection of electromagnetic radiation. Microwave absorbers are used in an anechoic chamber along with its wall, ceiling and floor for the electromagnetic compatibility (EMC) and electromagnetic interference (EMI) evaluation. This research is to develop a flat shape of biomass absorbers using an agricultural material. The main material used in constructing the flat absorber is a natural bamboo. The flat shaped absorber is chosen because it could reach the standard set in the specified industry and suitable to be used in the microwave frequency range. Cylindrical bamboo with different radius have been used for this study. Radius 0.2 cm for Design 1 and 1 cm for Design 2. The range of frequencies are set in the range from 1 GHz to 12 GHz. The result of microwave absorber is analyzed for its absorption performance. The generated result from the technique shows that the flat stick bamboo microwave absorber operates the best in Design 2 with 34.9% of absorption performance compared with Design 1. The overall results in different angles for both designs are analyze and compared.

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Microwave absorber is commonly used in defense, electromagnetic compatibility (EMC)/electromagnetic interference (EMI) reduction and anechoic chamber application. Conventional electromagnetic (EM) absorbers have some constraints in practical handling due to its heavy weight. In this paper, the research focuses on the development of high performance and lightweight microwave absorber. A lightweight and simple design configuration of different rectangular slot size array implemented on hollow pyramidal microwave absorber are carried out. There are two different designs of different slot size array calculated based on 3GHz, 6GHz and 9GHz frequency slot size. The two designs have an opposite slots size array arrangement namely different slot size 3GHz, 6GHz, 9GHz order design array and different slot size 9GHz, 6GHz, 3GHz order design array. The absorption is measured using the Naval Research Laboratory (NRL) arch free space method in the frequency range of 1GHz to 12GHz covering L, S, C and X band. In the measurement result, the maximum absorption performance is obtained by the different slot size 9GHz, 6GHz, 3GHz order design array which is up to -44.23dB at X-band. The measurement results for both designs array show good absorption performance which exhibit below than -20dB especially at high frequency band. The proposed designs have been identified as the new approach to increase absorption improvement over a broad frequency range application.