There are many advantages in using tracking antenna in RF product design. Good performance with frequencies > 900 MHz, low cost and small size are several examples of the popularity of tracking antennas. When implementing a tracking antenna, keep these 7 keys in mind to make your antenna design perfect. Learn about the common antenna types available, and the widely available standard designs include monopole, L-type and F-type. The standard F-type antenna is the most widely used and provides the best compromise between size, efficiency and omni-directional. You can use meandering routing to reduce PCB area, but at the cost of performance.

Considering the structure of circuit board, the length of PCB will determine the resonant frequency; the length of PCB will determine the resonant frequency. The higher the frequency, the shorter the wiring. Each antenna needs to reserve a certain area on the PCB. Defined as the area around the antenna routing, in which copper wiring or grounding cannot be used on any layer of the PCB. The wider the trace, the better, because they usually provide a wider bandwidth. Traces can be gold-plated or covered with solder mask. The electrical properties of the antenna will be used when the substrate material, its thickness and dielectric constant (ε) are determined – [R].

Ground level matters! PCB routing antennas depend on the ground plane because they must have an effective ground plane. The shape and size of grounding plane relative to antenna will affect the impedance and performance of PCB antenna. The ground plane should have vias on the entire edge of the antenna away from the area.

Some points for attention when using tracking antenna in RF product design

Always including matching components and mismatched antennas can significantly reduce the overall RF link budget and range performance. Ensure that the PI network directly placed at the antenna feed point is incorporated to prevent unnecessary mismatch loss. Note that the use of the antenna environment, plastic shell, metal parts and other parts close to the antenna will affect the antenna rotation and radiation pattern. Do not put the antenna close to metal objects, and do not use metal or metallized plastic shell. Ideally, the external influence is kept in the far field of the antenna.

Each application requires tuning. All PCB antennas are board specific, and each implementation requires sizing and matching. Copying an existing design does not guarantee good performance. The gain and radiation pattern will vary with the parameters in the surrounding area. The length of the antenna will need to be adjusted according to these variables. In addition, the final adjustment and matching should be done in the shell and installation of the final product, not in the open air.

Antenna matching is necessary! When the antenna impedance matches the source impedance (50 ohm), the maximum RF power will be transmitted. The return loss < > < > is regarded as the quality factor of good antenna matching. This means that 10% of the incident power is reflected due to the mismatch. The antenna return loss is characterized by measuring the reflected power at the antenna feed point (plus matching components). The antenna is disconnected from the transceiver and the network analyzer is connected to the antenna via a coaxial cable to perform the measurement. Remember that the antenna must be tuned when placed in the position and environment used during normal operation.

     

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