How to Define a PCB Antenna and Determine Its Specifications

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In a high-frequency printed circuit board (PCB), the PCB antenna is a transducer that converts current waves into electromagnetic (EM) waves. PCB antennas transform high-frequency electric current into electromagnetic waves that may travel across the air.

A high-frequency PCB often has two PCB antennas built into it. They are included in the PCB itself, taking the form of the etched copper structure. The reflected radio frequency signal is picked up by the second antenna, while the radio frequency signal being broadcast is done so by the first antenna.

The high-frequency circuit produces radio frequency (RF) waves and analyzes the signals reflected from those waves; the signals are then sent to the PCB antenna via the base materials of the circuit board. The high-frequency PCB’s whole radio frequency (RF) system comprises the PCB antennas and the high-frequency circuit.

The size of the PCB antenna is meant to be highly compact and smaller; however, to obtain the necessary gain from the minimal size of the antenna, numerous microstrip patches are joined to maximize efficiency and achieve the needed gain. The wavelength of the intended operating frequency has an immediate and direct influence on the size of the patch.

Antennas Can Take Many Forms

Antennas are used to develop a high-frequency PCB, which also incorporates antennas. It is necessary to have a prior understanding of various kinds of antennas to comprehend how PCB antennas perform their functions. Following this, we will go over each of them in turn.

loop antenna

The loop antenna is the most basic form of the PCB antenna family. It consists of a simple PCB board with a closed loop, which may be linked to receiver or transmitter terminals. This antenna may have the shape of a circular or rectangular loop.

The effectiveness of this antenna is determined, in part, by the size of the loop that it consists of and the amount of copper utilized in its construction. Loop antennas are not utilized for transmission since they are very inefficient compared to the wavelength; instead, they may be used as receptors. Another purpose for loop antennas is to detect radio waves.

Patch antenna

The patch antenna has the form of a square, circular, or another geometric patch of copper on the printed circuit board. The wavelength of radio waves is about equal to one-half the length of the patch antenna’s span. At microwave frequencies, patch antennas are most beneficial due to their ability to construct tiny patches thanks to the short wavelengths at those frequencies..

slot antenna

The slot antenna is the last antenna that will be discussed here. Because of its design, which consists of a metal plate with numerous slots or cuts, this kind of antenna is referred to as a slot antenna. The magnetic and electric fields produced by a slot antenna are inverted compared to a dipole antenna. Both phased arrays and aircraft radars use slot antennas in their respective applications.