The PCB antenna is composed of a line on the printed board (PCB). It places communication circuits and antennas on the same plate, and realizes seamless grafting of other circuits on the antenna and board, so its production cost is relatively low. Widely used in communication products, such as mobile phones and radio. The advantages of PCB antennas are high cost performance, easy design, and greater freedom.
How does the PCB antenna work?
The PCB antenna moves in a certain shape, which causes scattering. They may be wires on the surface of the circuit board, or they may even be poles of high frequency AC power. In the high-speed circuit, the ground floor is kept charged, so the charge will not spread. We do this to avoid noise and electromagnetic interference. However, the antenna must be designed to radiate and receive radio waves. Therefore, they deliberately stay away from the reference plane.
Which electronic products are mainly used for antennas?
Many products now add wireless functions, such as Bluetooth modules, WIFI modules, ZigBee modules, etc., PCB antennas are widely used on mobile phones, wireless sensors, smart home devices, and the Internet of Things. They can be designed as a very small size to fit the limitations of these devices.
What are the key factors in designing radio frequency and microwave antennas?
First, determine the frequency range, such as central frequency and operating bandwidth. In addition, understand the required power level. Next, determine the antenna size according to the stack layer. Set all design constraints. These are all iterations. From the choice of materials to the size of the antenna, all this plays an important role.
How to make the antenna layer structure
(1) An antenna layer structure, comprising: an antenna substrate layer; an antenna unit on the surface of the antenna substrate layer, which includes radiation patterns and antenna pads; the surface of the surface is relative to the surface and the insulating layer of the cushion at the same level, and the antenna cushion is superimposed on the pads in a thick direction.
(2) The antenna pad includes a signal pad connected to the radiation pattern and grounding pads formed around the signal pad.
(3) The antenna layer structure has a cushion area where the radiation area and the antenna are located, and the pad is formed in the pad area.
(4) Set the coverage window on an antenna unit.
(5) The radiation grounding of the bottom surface is provided on the insulating layer, where the radiation pattern is superimposed on the radiation ground in a thick direction. The pads are connected to each other and the radiation ground, and the ground is connected to the ground side with the radiation ground side.
(8) Set the display panel on the bottom surface of the insulating layer and use the display panel as a radiation ground.
(9) The display panel includes a display device having an electrode layer, and the electrode layer of the display device is used as a radiation ground. Wherein the antenna substrate layer or insulating layer is used as a packaging layer covering the display device.
(10) According to the structure of the antenna layer (1), the pads are in contact with the antenna substrate layer.
(11) According to the antenna layer structure (1), the radiation pattern has a mesh structure.
(12) According to the structure of the antenna layer (11), the antenna unit further comprises a mesh pattern disposed around the radiation pattern.
The antenna layer structure according to an embodiment of the present invention may include pads that are overlapped with antenna pads in the thickness direction. The antenna pad can be used to achieve resonant frequency matching and impedance optimization, thus improving gain and radiation characteristics at specific frequencies. In addition, antenna mats and pads can be adjacent to each other to further increase antenna gain.
How to separate two patch antennas on PCB?
Multiple patch antennas are used for greater power and sensitivity. These arrays are placed in an array, and these arrays are separated by half or a quarter of the waves according to the direction. This direction should allow the signal to increase signal strength or sensitivity.
What are your suggestions for installing the PCB antenna?
There are two key factors when installing antennas: directional: Typical IoT applications use quite omnidirectional antennas. However, if they are above the ground plane, it will exhaust the energy of the antenna electromagnetic field. As a result, it will interfere with the signal. Using patches can avoid this, because the ground layers are part of the transmission. Other types of antennas, such as inverted F-type and twisted antennas, should be installed at a distance from the ground. But you should still connect them to a reference plane. Diversity: Install the antenna element at a 90 degree angle to improve the reception effect of the entire sphere around the product.
What is the best material for an antenna board?
The best material is a low loss power medium, but it depends on the application. If it is a low power consumption and small-scale ISM frequency band application on the Internet of Things, WiFi, Bluetooth, etc., ordinary FR4 can be used. When dealing with high power or longer, you should consider losing and choose Rogers Electric or other ceramic filler materials. Because the DK value is low, you need a larger object to match the impedance. On the contrary, they have a low positive loss, which is extremely important in the patch array for increasing the power of long-distance transmission.
How to get better performance?
If the correct ground plane is allowed and the antenna is in a very good position, you already have a good start, but you can do more to improve antenna performance. You can use matching networks to adjust the antenna – this will compensate for any factor that may affect antenna performance to some extent.
The key radio frequency component is an antenna, which matches the network and its radio frequency output. The configuration of these components to minimize signals will be minimized. Similarly, if your design includes a matching network, if the wiring length of the antenna matches the wiring length specified in the manufacturer’s product specifications, the antenna will perform very well.
The shell around PCB may also be different. The antenna signal cannot be transmitted in metal, so placing the antenna in a metal shell or metal housing will not be successful.
Also, be careful when placing antennas near the plastic surface, as this can cause great damage to antenna performance. Some plastic (e.g., nylon filled with glass fiber) is lost and will be attenuated to the RF signal of the antenna. The dielectric constants of plastics are higher than air, which will seriously affect the signal. This means that the antenna will record a higher dielectric constant, which increases the electrical length of the antenna and reduces the frequency of antenna radiation.