1.1 INTRODUCTION
Wireless communication have experienced a rapid development and plays important role over
the last two decades and have become an integral part of our daily lives. Cellular networks, radio
broadcast and TV broadcast are just a few examples of the wireless technology that we are using
everyday. These wireless system also radiate a large amount of electromagnetic energy into the air
but most of them are actually wasted. [A]
The concept of Rectenna as RF energy harvesting system plays important role in gathering
clean energy from surrounding environment effectively and efficiently. Rectifying antenna or
rectenna is one of the primary components in the RF energy harvesting system. Which is used to
captured RF signal and convert it into a DC voltage. [D]
In the recent years, the research based on the technology of empowering very small devices
like biomedical implant devices, wireless sensor nodes, storing the energy in rechargeable microbatteries and super capacitors by ambient of energy recycling attracts the interest of researchers
and engineers. Wireless energy harvesting is necessary especially for biomedical implant or
wireless sensor nodes because recharging or replacing the batteries of these tiny devices is non
feasible. The best choice to counter these problem is to recycling or harvesting from RF waves
because the environments is full of radio energy. [C]
Rectenna have unique on developing interest in both theoretical research and engineering
applications due to their live time, which is almost unlimited and it does not need replacement
(unlike batteries). The Rectenna consist of a receiving antenna to receive microwave energy or RF
signal followed by low pass filter, impedance matching network and rectifier circuit.
Energy harvesting is an important process for most of the country. To increase wireless
production, various suggestions have been made. The research reported in investigated the radio
frequency (RF) antennas in this era, which have helped in improving the RF communication model
of an antenna to the peoples. Instead, the demand for green technology like RF energy system is
also important to overcome this problem due to advances in wireless broadcasting which have
been agreed in. Therefore, the new technologies adaptations are required to improve on the batteryfree production and productivity as stated in research] by supplying sufficient ambient energy to
the devices. [SC1]
1.2 PROBLEM STATEMENT
In 21st century’s the technologies has caused the electronics products to be lighter, cheaper
and smaller in size. The world has witnessed an unprecedented increase in its energy requirements
over the last few decades driven by the development and the increasing size of population,
industrial development and the increasing level of activity of humans around the globe.
Consequently, new paradigms are needed to produce clean, cheap and recycle energy of
our daily life. Rectenna have unique on developing interest in both theoretical research and
engineering applications due to their live time, which is almost unlimited and it does not need
replacement (unlike batteries). The Rectenna consist of a receiving antenna to receive microwave
energy or RF signal followed by low pass filter, impedance matching network and rectifier circuit.
[ A]
In order to achieve the expected conversion of efficiency in the simulation, the proposed
design of rectenna needs greater consideration on all aspect of requirement especially on type of
material used and related parameters.
1.3 OBJECTIVES
The objectives of this project can be summarize as follows:
1)
To investigate Rectenna with good matching impedance and rectifying
Circuit for wireless energy harvesting.
2)
To design and simulate microstrip patch antenna integrated with rectifier as
Rectenna using FR4 substrate using Computer Simulation Technology (CST)
Studio software.
3)
Analyze the performance of the rectenna in various processing condition on low
power density
1.4 PROJECT SCOPES
This project is focused on designing a suitable RF antennas for energizing low power
electronics circuits. The antenna used in this project is the microstrip patch antenna that operate at
2.45Ghz. The reason why this type of antennas was chosen is because they are lighter in weight,
low volume, low cost, low profile, smaller in dimension and easy to fabricate and conformity.[ ]
Fabricate of the microstrip patch antenna and rectifier circuit on FR-4 material with dielectric
constant εr is 4.3 and substrate thickness h is 1.6 mm.
Perform numerical solution using CST Microwave Studio and investigate the performance of the
rectenna in term of conversion efficiency.