Experimental Analysis on Double Layer Kapton Material using Peltier Thermoelectric Device

Kapton is one of the flexible materials used in the development of microwave components for the telecommunications system. The electrical properties of Kapton are dependent on the material's temperature. In this study, this material will be heated, and the electrical properties of dielectric permittivity and loss tangent will be analyzed. This material heating process is done by using Peltier thermoelectric which is installed with Aluminium alloy. The 0 V up to 7 V DC voltage was supplied to the Peltier during the heating process. Then, the electrical properties of Kapton were measured by using a dielectric probe and vector network analyzer (VNA) at frequencies of 1 GHz to 9 GHz. The results obtained show the Kapton temperature was increased from 27oC to 41oC. Meanwhile, the dielectric permittivity also varied from 1.72 to 1.64 at the frequency of 5 GHz when 4 V was used. The maximum loss tangent value of 0.5 was observed when the maximum DC voltage of 7 V was applied. The knowledge of this experimental work can be used to design reconfigurable microwave components for smart system application

Dual Polarization Single Port Inset Feed Microstrip Patch Array Antenna

This paper present the designs of array antenna from type of inset-fed microstrip patch antenna by using single port oriented at 45° and -45°. The antennas are capable to generate dualpolarization radiation pattern centered at 45° and -45°. Combinations of two patches using quarter-wave impedance matching technique has been used to designs the array antennas operate at 2.4 GHz. The designs are simulated using Microwave Office 2004 and were fabricated on FR4 substrate with a dielectric constant εr =4.7, tan δ =0.019 and thickness =1.6mm. The simulation and measurement result have been compared. The 3 design 1x2 array antennas yield a bandwidth greater than 5%. The gain of the proposed antennas is also stable with operated frequency. The result showed that the combination of more patches in array can improve the return loss and gain performances. 

Circuit Modeling of Defected Waveguide Structure

Recently, waveguide has been applied widely in antenna and filter applications. Among these applications, substrate integrated waveguide has been implemented mostly in millimeter wave systems due to its compact and low loss approach. However, the configuration of waveguide itself receives less attention. Thus, the study of defected waveguide structure (DWS) is presented. The copper and DWS waveguide were designed in CST Microwave software. The basic geometry of square was used and then different types of connecting strips were added on in between the strips. Simulated reflection coefficient (S11) and transmission coefficient (S21) results were then modeled by equivalent circuit design. The circuit was constructed in Advanced Design System (ADS). Copper waveguide performed high pass at frequency more than cut off frequency of 2.76GHz. The square DWS with gap separation and square DWS with horizontal connecting strips showed pass band around 4GHz-8GHz. The square DWS with vertical connecting strips and square DWS with both horizontal and vertical connecting strips created band stop around 3GHz-9GHz

Design of Wideband Low Noise Amplifier using Negative Feedback Topology for Motorola Application

This paper describes the design of wideband low noise amplifier (LNA) for Motorola application which targeted to be applied in two-way communication mobile system architecture. The technical specification was deduced from the TIA-603C standard receiver system sensitivity and intermodulation. The proposed LNA exhibit low power consumption and adopts a negative feedback wideband amplifier topology, operated from 100 MHz to 1 GHz which covers the whole Land Mobile FM Communication Equipment (136 – 941 MHz) frequency band. The proposed topology solve the RF tracing problem inherited in the targeted frequency and also the problem of economically impractical PCB size rendered by other wideband amplifier methods. The Advanced Design System software is used to perform the simulations. The measured result show the proposed LNA using FR4 board has a stable gain of more than 15 dB, noise figure less than 1.5 dB, S11 and S22 less than -10 dB, with current consumption of 8mA from voltage supply at 1.8

Enhanced Integrated Indoor Positioning Algorithm Utilising Wi-Fi Fingerprint Technique

This paper describes an integrated positioning algorithm utilizing Wi-Fi fingerprint technique for indoor positioning. The main contribution of this work is the improvement of positioning accuracy for indoor localization even in extreme RSSI fluctuation which leads to variation of positioning error. Several layers of Wi-Fi positioning is proposed, which are based on deterministic techniques, iterative Bayesian estimation, and also Kalman filter to enhance accuracy due to noise presence. Here, accumulated accuracy is introduced where the distribution of location error is determined by estimation at each test point on path movement. The results show that the integrated algorithm enhances the estimation accuracy in several scenarios which are different Wi-Fi chipsets and movement directions. The error distribution shows an achievement of up to 65% for error less than 5m compared to the basic deterministic technique of only 45%