Spiral antenna with reconfigurable HIS using liquid crystals for monopulse radar application

In this paper, the design of an electronically reconfigurable ground plane composed of a high impedance surface (HIS) based on liquid crystals is presented and used as a backing structure for a two-arm Archimedean spiral antenna. The structure is used to provide electronic switching of two different shaped radiation patterns for monopulse radar application; 1) sum-pattern (Σ-pattern), and 2) difference pattern (Δ-pattern). The antenna arrangement is shown to exhibit either the Σ- or the Δ-beam by changing the permittivity (and hence reflection phase) of the HIS reflector when a bias voltage is applied between the periodic array and ground plane. The HIS is demonstrated to resonate at 6 GHz, and numerical results are employed to investigate the performance of the HIS-backed spiral arrangement, i.e. radiation pattern, impedance match, realized gain (Σ-pattern), and null depth (Δ-pattern)

Performance Enhancement of a UWB Antenna Using Backing Cavity for Improved Wireless Communication Systems

Ultra Wideband (UWB) is a wireless technology for transmission of massive amounts of data over a wide frequency band using short-pulses with very low power spectral density. In 2002, FCC authorized a frequency allocation in the range of 3.1–10.6 GHz with a maximum transmitted power of -41.3 dBm/MHz for UWB commercial use. Certain applications require unidirectional radiation and thus, antennas are usually backed by either a cavity absorber or a conducting plane reflector. However, the use of absorber will decrease the efficiency to only 50%, while the metal reflector is restricted with a quarter wavelength separation between the reflector and antenna for maximum performance. The objectives of this project is to enhance the performance of wideband antennas for several communication applications which exhibit good radiation patterns with high gain and front-to-back ratio, provide acceptable impedance, with a compact and lightweight structure. The geometrical design of the antennas will be studied and the simulation/design of the antenna will be executed using CST Microwave Studio® (CST MWS). These wideband antennas can be used for military applications such as avionics and microwave direction-finding systems, CubeSat, 5G technologies and other wireless communications e.g. WLAN, WiMAX and Bluetooth, which will be a significant contribution for Malaysia in enhancing its wireless communication

Study of a flexible antenna for intelligent transport system application

—This paper presents flexible microstrip antenna designs that can be used for Intelligent Transportation System (ITS) operating at a frequency of 5.9 GHz. Designing the flexible antennas for ITS provides alternative to automotive industry to place the antennas at various shapes and conditions. Two antenna arrangements are introduced to produce two different radiation patterns; omnidirectional and directional. Both antenna arrangements consist of a radiating patch and a ground plane which were printed on different side of dielectric substrate. In order to identify a suitable substrate for ITS application, each antenna arrangement is designed on three different substrates. Numerical predictions of the performance parameter from six different antennas, are compared and used to investigate the antennas flexibility, where the antennas are bent towards a cylinder with different radius

A compact and lightweight microstrip antenna array with Wilkinson power divider for X-band application at 9.5 GHz

In this paper, a two-element microstrip antenna array with a compatible 1:2 Wilkinson Power Divider operating at 9.5 GHz for X-band application is presented. The design, simulation and optimization of this work are performed using Computer Simulation Technology (CST) Microwave Studio. The proposed design is shown to exhibit good simulation performances with return loss of -38.21 dB, bandwidth of 493 MHz, and gain of 7.08 dB. Coupled with the antenna array, a 1:2 Wilkinson Power Divider is then designed, simulated and optimized. The simulation result of the power divider exhibits three modes of resonance at 8.0-8.5 GHz, 9.09-10.28 GHz and 11.2-11.5 GHz. The operating frequency at 9.5 GHz resulted an equal power division with insertion loss less than 3.68 dB and less mutual coupling as the isolation factor is at 16.23 dB. The antenna array and Wilkinson Power Divider configuration produced an overall dimension of 83.14 mm 67.34 mm, which realized a portable solution for the parabolic reflector antenna

Automatic metal waste separator system in Malaysia

Metal recycling is an issue that needs attention and should be practiced by people as it has many advantages to human and Earth. In order to get a metal from Earth, the process called mining are needed where it can harm our natural resources due to depletion of the area to be mined. If the process is not controlled, most of the areas on Earth will have huge excavation holes. So, people should be responsible to prevent this from happening to preserve the environment in a good quality by recycling the metal material. By metal recycling, it can save an energy and resources as it can reduce the demand for raw materials, hence maintain the natural resources for the future. The proposed automatic metal waste separation system is intended to ease the people to separate the waste material. Besides, it will make the metal recycling industry work easier because the metal waste is already isolated at garbage collection side. The purpose of the project is to design a system to separate the metal recyclable household waste automatically and record the data waste collected. There are total of four detectors used to separate the non-metal, steel, copper and aluminum metal waste. The average time used to complete metal separation process by using the proposed prototype is 14.5 seconds. This project includes a mechanical part, programming part and an electronic design. The system will be programmed using Arduino Mega as a microcontroller to control all the electronic component in the system

Smart street light using intensity controller

Smart street light is an intelligent control of street lights to optimize the problem of power consumption of the street, late in night. Currently, usual street lights are automatically turn on when it becomes dark and turn off when it becomes bright. This is huge waste of energy in the entire world as it is an essential community service, but current implementation is not efficient. Conventional street lights are being replaced by Light Emitting Diode (LED) street lighting system, which reduces the power consumption. The focus of this project is to design a system of street lights controller to provide a reduction in power consumption. The prototype is design by using Light Dependent Resistor (LDR), Infrared sensor (IR), battery and LED. All this component was controlled by Arduino UNO as the microcontroller. The brightness of the lamps is being controlled in this project to reduce the power consumption. The dimming of the lamps depends on the speed of object motion detected such as pedestrians, cyclists and cars. The higher speed of moving object, the greater the level of intensity. For this idea, the innovation of street lights is not quite the same as conventional street lights that are controlled by timer switch or light sensor which automatically turns the street lights on during sunset and off during sunrise. According to the study, motion detection devices may help to save up to 40% of energy per month

Energy efficient smart street light for smart city using sensors and controller

Smart street light is an intelligent control of street lights to optimize the problem of power consumption of the street, late in night. Conventional street lights are being replaced by Light Emitting Diode (LED) street lighting system, which reduces the power consumption. The focus of this project is to design a system of street lights controller to provide a reduction in power consumption. The prototype was designed by using Light Dependent Resistor (LDR), Infrared sensor (IR), battery and LED. The brightness of the lamps is being controlled in this project to reduce the power consumption. The dimming of the lamps depends on the speed of object motion detected such as pedestrians, cyclists and cars. The higher speed of moving object, the greater the level of intensity. For this idea, the innovation of street lights is not quite the same as conventional street lights that are controlled by timer switch or light sensor which automatically turns light on during sunset and off during sunrise. According to the study, motion detection devices may help to save up to 40% of energy per month

Classification of different types of metal from recyclable household waste for automatic waste separation system

Nowadays, solid waste has become a major problem in Malaysia. However, most people in Malaysia are not aware and take this problem for granted. The rising number of population and massive development in recent years indirectly generated an enormous value of household waste, making the household waste the main generator for solid waste in Malaysia. It stated that only 5 percent of an average 30,000 tons of waste have been recycled in Malaysia. The purpose of the paper is to design a system to separate the metal recyclable household waste automatically and record the data waste collected. There are total of four detectors used to separate the non-metal, steel, copper and aluminum metal waste. The average time used to complete metal separation process by using the proposed prototype is 14.5 seconds. This paper includes a mechanical part, programming part, an electronic design and also the data collected from this proposed system. The system will be programmed using Arduino Mega as a microcontroller to control all the electronic component in the system

Discrimination of residual and recyclable household waste for automatic waste separation system

Most of the countries in the world are confronting a gigantic issue of waste management system. Due to the rapid urbanization and increasing population, huge volume of waste is produced year by year. Improper waste management system has created a deep concern among people which lead to disturbance to the environment and human health. In this paper, a fully automated system that discriminate residual and recyclable household waste is proposed. It is shown that the prototype system are able to automatically separate waste into residual and recyclable waste by employing a moisture sensor to sort them into wet (residual) and dry (recyclable) waste. The state of the waste is determined by its resistance to current value and the percentage of water content

Material classification of recyclable waste using the weight and size of waste

Nowadays, insufficient landfills problem had increased the needs to decrease the waste and recycling them. However, despite the efforts done by the government and local authorities on promoting recycling culture by introducing new laws and regulations, the awareness and willingness among the community is still low. One of the possible reasons to this is lack of effort to categorize the waste into the designated category which are paper, glass, plastic and metal. In order to address this problem, it is important to design a system that will ease the process of categorizing the waste. This can be achieve by the automation of the said process. In this work, a system consist of an algorithm and hardware to automatically categorize recyclable waste is proposed. The proposed system are utilizing weight sensor and ultrasonic sensors in order to capture the characteristics of the waste item, which are weight and size so that it can be categorized into paper, glass, plastic and metal. Here, an algorithm to compensate minimum usage of hardware, namely the type and number of sensors is presented