We will also build the complete PCB from this circuit diagram in the next article. Here we are designing the 2.4 GHz antenna for ESP8255 Mini board, so below is the circuit diagram for the same. The microstrip width to depth ratio is determined by,Įnough! With the Calculations, let's design An ESP8285 based 2.45GHz RF board to show how easy it is and how complicated it can be to design a board and an RF module on board.
The length of the trace can be determined using The Width of the trace can be determined using The height of the substrate can be calculated by using, To explain the design of the antenna, we are assuming that PCB is made out of FR4 material which has a relative permeability of 4.4, this parameter is very important as we will see later in the calculation. Antenna Calculationsīefore we start the calculation, we need to set some parameters straight.įirst, we have to select the substrate, and operating frequency, next we have to calculate the appropriate length and width of the substrate, and finally we will calculate the length and width of the trace. At this point, this project is getting very long, so to shorten it up a bit, I am not going to explain why I am going for a meander line inverted F antenna, if you want to know more about these two types of antennas, you can check out this article on A Design on PCB with a Meandering Line and Shorting Strip. We have decided earlier that we are going to use the quarter wavelength antenna for this project, so depending on the requirements, there are only two major types of antenna that dominate all others which are:Īnd we are going to use the meander line inverted F antenna.
With that being said let's design it! Choosing the right type of antenna Instead, I am going to discuss some of the core concepts, best practices, and things to keep in mind. Now the basic out of them, we can turn our focus to the main attraction of the blog which is PCB antenna design.īefore continuing, let me tell you that I am not going to go bit by bit and explain all the very details about every aspect of a PCB antenna because I do not have the level of expertise, tools, and measurement needed for this kind of detailed explanation. So, if you do the same calculation for 2.45GHZ, we will get an antenna length of 23mm. The above basic example was to show you how you can calculate the wavelength for a certain frequency the mechanical length is inversely proportional to the numerical value of the frequency Īnd the wavelength (λ) = C/f = 3*10^8 / 50*10^6 = 6mįor a quarter wavelength antenna, it becomes λ /4 to be fixed. The length and shape of the antenna is related to the wavelength of the transmitter frequency i.e. In an antenna, wavelength, frequency, and antenna length depend on each other, I am going to explain these three parameters with a basic example. The above discussion is an over-simplification of the process that is encountered in the RF transmission but you can view it as a basis for further discussion Wavelength, Frequency, and Length of an Antenna
it must have the ability to transfer energy from electrostatic to electromagnetic, if the impedance match is correct, the energy will begin the transfer and it will be radiated into the atmosphere in the same way that a transformer transforms energy from its primary to secondary. In general, you can say it's a special type of transducer that converts high-frequency currents into EM waves.Īn antenna must have the ability to match the transmission line and the load, depending upon the frequency, wire length, and dielectric material, the wire acts as an impedance matching transmission line, we will discuss more on this later in the article.Īn antenna somewhat must act as a resonance circuit i.e. It's proven that to transfer maximum power, the source impedance must exactly be equal to the load impedance.Īn antenna is a structure that is made up of metallic objects, often wire or a group of wires used to convert high-frequency current into electromagnetic waves and vice versa. To understand antennas better, one must take a quick review of impedance matching and resonance circuits.