142 PIERS Proceedings, Guangzhou, China, August 25–28, 2014 Reflection Loss Performance and Performance Assessment of Pyramidal Microwave Absorber Using Agriculture Waste M. S. Mezan 1 , M. F. A. Malek 2 , M. S. Jusoh 1 , F. S. Abdullah 2 , and N. A. M. Affendi 2 1 School of Business Innovation and Technopreneurship, Universiti Malaysia Perlis Jalan Kangar-Alor Setar, Kangar, Perlis 01000, Malaysia 2 School of Electrical System Engineering, Universiti Malaysia Perlis Pauh Putra Campus, Arau, Perlis 02600, Malaysia Abstract— Agricultural product is one of the major revenue incomes for Malaysia. The large scale production of agricultural product lead to a new by product which is known as agricul- tural waste. Agricultural wastes materials can be applied for many applications. This research highlighted microwave absorber application as the output using proposed agricultural wastes. Mi- crowave absorber is the most important element in anechoic chamber to deny signals reflection. Its performance is analyzed in term of reflection loss performance using the free space measure- ment technique. To answer the measurement goodness in this research, Rasch measurement model is applied. 1. INTRODUCTION This research considered the alternatives way to utilize the agricultural waste and take the advan- tage from the pile up of the availability of wastes. The increase production of agricultural waste raise the loses of resources and produced the environmental damage. The utilization of agricul- tural waste may reduce the dumping of waste and become a substitute material for commercially available microwave absorber which use 100% chemical based of plastic foamed-based materials like polystyrene or polyurethane [1]. The proposed product from the waste is microwave absorber. Microwave absorber is used as the important element in anechoic chamber which is covered on the chamber wall. The microwave absorber will act as the absorbent material to absorb the scattered incident energy. For diversification in the material for microwave absorber, several agricultural residues are used in this research which is rice husk, mixture of rice husk and rubber tire dust, sugarcane bagasse and banana leaf. 2. MICROWAVE ABSORBER FABRICATION The grinded material of agricultural wastes is fabricated into the shape of pyramid. Besides of the material’s effect in microwave absorber, the shapes of the microwave absorber will also play the important characteristics and sensitive factor which can affect the reflectivity performance of the microwave absorber [1]. Pyramidal shapes absorber are usually applied for the frequency range between 1 GHz to 40 GHz and the square based pyramidal-shaped absorbers are commonly used for frequencies below than 1 GHz [2]. The material for microwave absorber is a mixed material of agricultural wastes and chemicals. The chemicals used are polyester which functioned as the resin and methyl ethyl ketone peroxide (MEKP) which reacts as a hardener agent for the materials to be moulded into pyramid. These polyester resins are used in adhesive, finishes and moulded objects. The characteristics are including low water absorption, volume resistance, heat distortion temperature, high tensile strength and elongation at break. For each materials of agricultural waste, nine pieces of pyramidal microwave absorber is made and compiled in 3 × 3 arrays, making the base dimension become 15 cm width ×15 cm length. Figure 1 shows four different materials moulded and compiled into 3 × 3 arrays. 3. SAMPLE MEASUREMENT TECHNIQUES The objective is to characterize the performance of its reflectivity for the different material mi- crowave absorber. Every result from the measurement will demonstrate the actual performance of the microwave absorber that had been fabricated for the measurement. The measurement tech- nique will involve two factors which were the microwave absorber electromagnetic properties and free space measurement to measure the reflectivity performances [3]. The measurement of dielectric properties is to characterize the different materials used and to define the physical and chemical properties, related to storage and loss of energy [4, 5]. For the