![]() ![]() The physical design of an antenna and its placement in a PCB will determine all of the above operating characteristics.Īntennas generally exploit some wave resonances within the antenna structure to create a strong voltage and current oscillation. Low loss along the feedline and front end. ![]() The goal of an antenna designer, both on a PCB or when integrated as an external component, is to define the geometry of the antenna so that some particular operating goals are met: This changing current emits a changing magnetic field the time-changing magnetic field then generates a changing electric field, and you now have a traveling wavefront emitted from the antenna! Physical Design of an Antenna After reflection of the far end of the antenna, superposition causes a current wave to form along the antenna. The pole antenna receives a current from a driver and acts like an open transmission line. The two images above provide a comparison of loop and pole antennas. Magnetic antennas use a loop of wire, and the transmitter/receiver element in the system acts like a load that completes a circuit that contains the loop antenna.ĭipole antenna (left) and loop antenna (right) with injected current. The simplest antennas are a single wire of specific length, the size of which will be discussed below. These elements are inherently operating in the wave propagation regime (as we will see below), so impedance matching must be enforced.Īntennas can be designed to pick up an electric field or magnetic field, depending on its geometry. The interconnect that leads to the antenna will need to pass a signal into the antenna or accept a signal from the antenna. PCB Antenna Design FundamentalsĪntennas perform two basic functions: they emit electromagnetic waves when provided with a voltage and current, and they receive electromagnetic waves and convert them into a voltage and current. In this article, we’ll present some of the main concepts behind antennas so that engineers can see how to design, select, and place antennas. The astute designer will soon notice that a PCB contains many elements that can act like efficient antennas. No matter if your antenna is placed as a printed element or pulled off the shelf, it’s important for PCB designers to know how antennas work at a deep level. Then there are PCB-mounted antennas like chip antennas and SoC modules with an integrated radio, which could also require an antenna module or off-the-shelf component. The antennas used in PCBs can also be printed, allowing for totally custom designs and unique architectures that are accessible in a single assembly. There are many antennas available as off-the-shelf components, and engineers can use there in many systems requiring some kind of wireless communication. ![]()
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