2.4G and 433MHZ PCB Antenna Design Guide
1.Printed Circuit Board Antenna Design
There are two main structures of 2.4G printed circuit antennas, PIFA antennas and single-pole antennas.2.4G and 433MHZ PCB Antenna Design Guide
Printed Circuit Board Antenna Design
There are two main structures of 2.4G printed circuit antennas, PIFA antennas and single-pole antennas. The antenna feed point and ground of the PIFA antenna are connected together, and a capacitive effect is formed between the antenna and the ground, that is, the signal is boosted to the equivalent capacitor through the antenna (equivalent to inductance), and the energy is radiated through the capacitor. The single-pole antenna adopts the 1/4 wavelength principle, one of the feed points is a spiral or a single pole, and the other pole is the ground. The field structure of the two antennas is simple, and can be simply equivalent to an LC resonant circuit, in which C is particularly small, and the resonant circuits are coupled one by one, and finally the electromagnetic field is released to the outside.
The capacitance of the PIFA antenna is much larger than that of the single-pole antenna,
that is, the energy is more in the resonant cavity, it is not easy to interfere with the outside world, and it is difficult to change the impedance of the PIFA antenna, so the stability is stronger than the single-pole antenna; but because its capacitance is too large, the same energy from the outside world enters, and the voltage change generated on the PIFA antenna is far less than that of the single-pole antenna. Therefore, the efficiency and sensitivity are lower than those of monopole antennas.
Generally, an external whip monopole antenna can be selected.
The communication distance of the external whip monopole antenna is longer, but each set needs to be debugged separately; a patch antenna chip can also be selected. The antenna chip occupies a small PCB size, but the price is higher.
In practical applications, considering factors such as cost and mass production stability, printed circuit board antennas have become the first choice for many wireless applications because of their low cost and adequate performance if properly designed. This article recommends three printed circuit board antennas, which can be applied to the small-size PIFA antenna on the Dongle end, the monopole antenna on the wireless mouse board, and the medium-size PIFA antenna on the remote control board. These antennas have corresponding simulation and verification results. If you need to refer to the corresponding antenna, you must strictly design it according to the antenna shape given in the document.
2.4G and 433MHZ PCB Antenna Design Guide
II. Bluetooth Antenna Design
Currently, the most common Bluetooth antennas include dipole antenna, planar inverted F antenna, meander line antenna, ceramic antenna, liquid crystal polymer antenna (LCP) and rod antenna (2.4G frequency only). Because of their nearly omnidirectional radiation pattern, simple structure and low production cost, they are very suitable for embedded Bluetooth technology devices. This document mainly introduces 4 antenna design methods.
Inverted F antenna
Meander antenna
Ceramic antenna
2.4G rod antenna
III. 433MHZ antenna design
■ The antenna needs to strictly follow the reference design we provide
■ The surrounding shell cannot be a sealed metal shell, and the part close to the antenna needs to be made of plastic (it cannot be sprayed with metal particle paint)
■ The antenna should be far away from the input stage (especially when the input stage is classD) and the magnetic steel of the speaker (if there is a speaker in close distance, use an anti-magnetic speaker as much as possible).
■ The distance between the antenna and other conductors should be at least greater than 15mm, and as close to the shell as possible
■ The routing of the RF part should have a complete reference ground and be routed according to 50 ohms
■ You can consider using RF cable leads and use a dedicated PCB to place the antenna
■ The routing of the antenna and the audio pre-stage and MIC should be as far away as possible to prevent RF interference with the audio
■ The differential audio routing should be as parallel and equal in length as possible, and no ground wire should be placed between the two lines.
■ RF routing cannot pass under the module, because the bottom of the module is generally a gnd layer. If the RF line runs on the main top layer and runs under the module, the distance to the gnd of the bottom of the module is very close, which has a great impact on the signal. In addition, RF routing vias also affect the signal and should be avoided as much as possible.
■ There should be no components or other routing in the antenna area.
■ For S-type antenna routing, the line spacing is 3 times the line width (for example, the line width is W=0.8mm and the spacing is 2.4mm)
Core Ridge Technology focuses on short-range wireless communications and provides solutions such as wireless chips, modules, and software technologies, including: Wi-Fi, Bluetooth, 2.4G, 433MHz, Zigbee and other IoT solutions. 2.4G and 433MHZ PCB Antenna Design Guide Detailed Document 2.4G and 433MHZ PCB Antenna Design Guide Go to our official website to download.
