Pid 3413425
Pid 3413425
Pid 3413425
Abstract— In this study we have designed a prototype modeling machine code, and still requires a connection to host computer
of antenna tower that will be used to help measuring the for the initial setup.
radiation pattern diagram of single element microstrip antenna
and 2 element microstrip array antenna. The system established In this study, the writer designed a modelling prototype
in this study utilized a raspberry pi microcontroller as controller antenna tower that can be applied on the measurement of the
and DC servo motor as the rotation driver of the antenna tower desired rotation angle. Tower which serves as the mounting of
mounted with 1 pcs for azimuth movement and with 2 pcs for antenna requires trigger and controller tools for its movement.
elevation movement. PWM signal via DMA that became the The trigger used is a DC servo motor and its motor movement
driver of the movement of the rotation angle of the antenna tower is controlled by a controller-based raspberry pi and a spectrum
is generated through the Python interfaces programming analyzer functioned to acquire the data received from the
language. antenna. The raspberry pi controller is selected as the system
control centre for the raspberry pi has more complete ports than
the controller used by the two previous studies. Complete port
I. INTRODUCTION of the raspberry pi allows its operation simply by inserting the
Each application requires an important magnitude as the SD card that contains the OS (operating system), connecting
antenna characteristics that determine whether it works on it or peripheral devices to the available port, and the power supply.
not and ensure the success of the process of designing an Also, the python programming language is chosen as an
antenna. One of the important magnitudes of the antenna interface program not only because the interpreter downloader
characteristics is the radiation pattern diagram. The diagram does not need to translate the script into machine code, but also
illustrates the radiation pattern of the distribution of energy it has the library that instructs PWM signal generation directly
radiated by the antenna in space [1],[2]. The measurement of to the raspberry pi.
radiation pattern diagram is helpful in distinguishing antennas
with isotropic radiation characteristics that can distribute the II. SYSTEM DESCRIPTION
energy to all fields with the same strong signal, which is
fictitiously illustrated, isotropic omnidirectional antennas only In order to provide a clear understanding of the
in a certain particular field, and a directional antenna that could measurement system, the system is described as follows: First
concentrate its energy toward a certain angle. The measurement of all, the AC voltage was set on regulator resulting 12 volts.
can be carried out with the method of near-field and far-field Because the input voltage required by the Rasberry Pi and the
by sampling the electric field and magnetic field generated by servo motor is 5 volts, the researcher used IC 7805 to handle it.
the measured antenna called AUT (Antenna Under Test) and After the booting process, the next step was to enter python
the referred antenna. Regarding the level of difficulty and cost, program through the LX terminal on the desktop. The program
near-field measurement method became an option as long as it was stored in the SD card to run in the file menu. The program
meets the conditions of the far-field. ran and was ready to be executed through F5. After it
successfully ran, the process of tower calibration was
To support the measurement of the radiation pattern automatically proceeding. This calibration was resulted by the
diagram on the near-field, it is necessary to design an designed program based on the pulse width set on the vertical
intelligent and simple system that can assist to indicate the side of 1500μs and 1450μs on the horizontal side. Finally, the
measurement with variation of azimuth angle and elevation instruction vertical and horizontal tower rotation was ready to
angle. There are two related previous studies using MSP430 proceed by following the instruction and the desired
controller [3] and the Teensy controller ++ 2.0 [4], each using elevation/azimuth angle. The formed angle and the rotational
the C and the Java programming languages as an interface direction depended on the given pulse width on the servo motor
program that requires downloader to translate the script into control circuit.