One of the most popular techniques for determining electrical properties of material is the free-space measurement technique. With the potential for new applications requiring efficient, accurate and broadband material measurement systems using higher millimeter-wave and terahertz frequencies, the free-space measurement method has received renewed interest. This is mainly due to its simplicity, favorable properties as a non-destructive method, and it allows transmission and reflection measurements without any physical contact with the sample. This paper reviews and discusses state- of-the-art free space material measurement systems, starting with the different measurement techniques available for material characterization, their important concepts, post-processing in determining their properties, and progress towards expanding their use at higher frequencies. Also, this paper reviews dielectric material characterization using the free space method focusing on their application extension towards the higher frequencies. Besides, the algorithms for conversion methods and usage of lens in free space material measurement system was discussed in this paper. Finally, a future perspective on the outlook of this free space method is presented prior to the conclusion.

One of the non-resonant techniques is the freespace measurement technique, which is popular due to its many advantages compared to the other techniques. It allows the transmission and reflection measurements without any physical contact with the sample. This paper discusses the free-space material measurement system in Ku-band which uses the NRW algorithm and Keysight (Formerly Agilent) 85071E software in determining the dielectric properties of materials. The permittivity and permeability of Teflon, FR4, PVC, ABS, Acrylic, polypropylene, polycarbonate, and epoxy were determined using free space measurement setup. For the first, a free-space measurement for Ku-Band is setup. It consists of a vector network analyzer, two horn antennas, sample holder, and Keysight 85071E software. The different role of transmission and reflection measurements on the achievable results is analyzed about experimental uncertainties and different noise scenarios. Results from the two strategies are analyzed and compared. Good agreement between simulation, measurement, and literature was obtained.

The internet of things, or IoT, is a game plan of interrelated handling contraptions, mechanical and propelled machines, objects, people that are outfitted with unique identifiers and the ability to move data over a framework without anticipating that human-should human or human-to-PC association. IoT in the study hall joins the advantages of IoT in content conveyance, business, and human services. It modifies and upgrades instruction by permitting improvement of all substance and types of conveyance. It empowers instructors to offer concentration to people and their technique. It likewise diminishes expenses and work of training through robotization of basic assignments outside of the real instruction process.

This paper proposes a reconfigurable antenna for RFID system which can operate between 860MHz to 960MHz frequency that belongs to ultra-high frequency (UHF) band used in Malaysia with the center frequency of 910MHz. One rectangular slot and two triangle-shaped slots are used in designing this antenna. A good circular polarization obtained from the slotted structure along the diagonal axis in the design. RF pin diodes are used as the switching mechanism of the antenna. However, in this work to proof the concept of switching mechanism, copper pins are used as artificial switches. Parasitic elements are deployed on the right and left side of the driven element to assist the radiation pattern reconfiguration. Overall, the proposed antenna able to steer the beam at approximately at -30°, -16°, and 10° with peak gain of 3.2dB and average gain of 2.5dB. With this result, overall coverage of UHF RFID reader antenna could be improved.