Antenna PCB

Description
Data Sheet

1. Overview

Maxipcb specializes in the R&D and manufacturing of antenna PCBs, covering various product categories such as GPS antenna PCBs, WiFi antenna PCBs, NB-IoT antenna PCBs, FPC antennas, and 5G antenna PCBs. These products are widely used in various wireless communication devices, providing core carrier support for the stable transmission of wireless signals.

2. Core Definition and Function of Antenna PCB

An antenna PCB is a functional part printed on a PCB board for receiving and transmitting wireless signals, essentially an energy conversion transducer. In the transmitting state, it can convert the high-frequency current output by the transmitter into spatial electromagnetic waves; in the receiving state, it can convert the electromagnetic waves captured from space into high-frequency current, which is input to the receiver.

Antenna PCB design is a core link in the design of low-power, short-distance wireless transceivers and Radio Frequency Identification (RFID) systems. A high-quality antenna system can effectively optimize the wireless communication distance and improve the stability and efficiency of signal transmission. According to the differences in application scenarios, the type and specification of the antenna PCB need to be selected in a targeted manner. Among them, in low-power, short-distance Radio Frequency Detection (RFD) systems, an antenna system with stable communication and controllable cost is required, and the PCB loop antenna is a common type in such scenarios.

With the popularization of 5G networks, the demand for wireless communication in various electronic devices is increasing day by day. As a core component of wireless communication, antenna PCBs have been widely used in many fields such as communication, the Internet of Things, and intelligent terminals, becoming a key support for the normal operation of wireless devices.

3. Suitable Materials for Antenna PCB

Antenna PCBs have high requirements for the high-frequency performance of materials, and conventional FR-4 PCB materials are difficult to meet their high-frequency use needs. At present, the materials that can be used for antenna PCB manufacturing mainly include: Rogers PCB materials, Teflon (Polytetrafluoroethylene) PCB materials, Arlon PCB materials, Taconic PCB materials, Nelco PCB materials, FR-5 PCB materials, Dupont PCB materials, and Isola PCB materials. Various materials can be flexibly selected according to the operating frequency, performance requirements, and cost budget of the antenna.

4.Correlation Between Antenna Length and Signal Frequency

The antenna length is closely related to the wavelength of electromagnetic waves. The conventional antenna length is about 1/4 of the corresponding electromagnetic wave wavelength. Therefore, the lower the signal frequency, the longer the required antenna length. The specific application scenarios are as follows:

1. FM radios with a frequency of about 100MHz need to adopt long rod antennas; walkie-talkies around 400MHz need to be equipped with external long rod antennas; 433MHz wireless serial ports commonly used in the Internet of Things also need to use external antennas.

2. In addition to 1/4 wavelength antennas, short antennas of 1/8 or 1/16 wavelength can also be used, but this will lead to a decrease in antenna efficiency. Some devices adopt the "short antenna + Low Noise Amplifier (LNA)" scheme, which can achieve the same receiving effect as long antennas; however, if a short antenna is to achieve the transmitting effect of a long antenna, the transmitting power needs to be increased.

3. Walkie-talkies need to transmit signals, so they all use external long antennas; while FM radios only need to receive signals and can use built-in receiving antennas.

4. Common frequency bands used in IoT communication, such as 2G (900MHz), 4G (700-2600MHz), WiFi and Bluetooth (2.4GHz), GPS (1.5GHz), etc., can all use built-in PCB antennas. In small products such as mobile phones, wearable devices, and smart homes, external antennas are rarely used, and built-in PCB antennas are generally selected. They have the advantages of high integration and beautiful product appearance, and are only slightly inferior to external antennas in performance.

5. Types and Characteristics of Common Built-in Antennas

Built-in antennas mainly include PCB antennas, FPC antennas, LDS antennas, and WiFi antennas. Each type of antenna has a unique product form, advantages, and applicable scenarios, as follows:

5.1 Built-in PCB Antenna

A built-in PCB antenna is a conductor directly printed on a PCB circuit board, widely used in single-band module circuit boards such as Bluetooth modules, WiFi modules, and ZIGBEE modules.

Advantages: No additional cost, no need for re-debugging after debugging, and strong stability;

Disadvantages: Only applicable to single-band scenarios (such as Bluetooth, WiFi), and the performance of PCB antennas in different batches may vary.

5.2 FPC Antenna

An FPC antenna is an antenna made of other external metal materials by stripping the antenna circuit on the PCB board, which is often used in mid-to-low-end mobile phones and smart hardware products with complex frequency bands.

Advantages: Suitable for almost all small electronic products, can be made into complex antennas with more than 10 frequency bands, with excellent performance and low cost;

Disadvantages: Need to be debugged separately for each product, with high debugging cost.

5.3 WiFi Antenna

A WiFi antenna is a communication antenna with an operating frequency in the range of 2.4GHz-2.5GHz, mainly used in scenarios such as Wireless Local Area Network (WLAN) and Bluetooth. According to actual use requirements, WiFi antennas can be divided into suction cup antennas, external rubber antennas, Fiberglass Reinforced Plastic (FRP) antennas, built-in PCB antenna boards, built-in FPC antennas, and other types. WiFi antenna PCBs have stricter requirements on the manufacturer's production precision and material control.

6. Key Manufacturing Points of Antenna PCB

In the manufacturing process of antenna PCBs, the following core points need to be focused on to ensure that the antenna performance meets the standards:

1. Antenna selection priority: If cost and size are not considered, patch antennas (small size, medium performance, medium cost) or external whip antennas (large size, high performance, high cost) can be selected; PCB antennas have the advantages of the lowest cost and moderate size, and can meet the performance needs of most scenarios as long as they are reasonably designed.

2. Selection of Dielectric Constant (Dk): The dielectric constant is a factor that PCB antenna engineers need to prioritize when designing microstrip antennas, and its value directly affects the circuit size. For a microstrip patch antenna with a specific frequency, the patch size decreases with the increase of the dielectric constant (Dk).

3. Selection of PCB thickness: The energy radiation capacity of the antenna PCB is positively correlated with the PCB thickness. The thicker the thickness, the easier the energy is to radiate to the outside. When designing antenna radiation units such as microstrip patches, priority should be given to PCB materials with larger thickness and dielectric constant (Dk) between 2.2-3.5; PCB materials with higher dielectric constant have lower radiation efficiency and greater design difficulty, but through optimized design, they can be used in scenarios that require miniaturized patch antennas.

4. Influence of copper foil surface roughness: Compared with the ceramic or Polytetrafluoroethylene (PTFE) medium of the PCB laminate, the surface roughness of the laminate copper foil will affect the antenna performance. For the same dielectric material (such as PTFE with glass or ceramic filling), the influence of rough copper foil on the antenna performance is greater than that of smooth copper foil.

5. Influence of surface electroplating: After surface electroplating of PCB antennas and other passive components made of PCB materials, the antenna performance will be affected. Ferromagnetic materials such as nickel will seriously affect the performance of PCB antennas; the antenna performance of the tin plating process is usually better than that of bare copper circuits, while the Electroless Nickel Immersion Gold (ENIG) electroplating process will lead to a decrease in antenna performance due to the inclusion of nickel.

6. Requirements for circuit surface cleanliness: The cleanliness of the circuit surface is crucial to the performance of microstrip PCB antennas and other microstrip passive components. A clean and residue-free circuit board is an important foundation for improving the performance of antenna PCBs. The performance of soldered circuit boards is usually better than that of bare copper circuits; if there are ionic contaminants or residues on the circuit surface, the antenna performance will decrease or even fail.

7. Requirements for etching quality: The etching quality of the PCB circuit board directly affects the performance of the antenna PCB. If the copper foil conductor is not fully etched, resulting in rough circuit edges and burrs, the performance stability of the PCB antenna will be reduced.

7. Summary and Service Tips

With the development of the communication industry towards high frequency, microwave PCB antennas, as the core carrier of high-speed signal transmission, play an increasingly prominent role in fields such as wireless communication. Maxipcb has a mature and stable manufacturing process for microwave antenna PCB circuit boards, which can meet the customized needs of various antenna PCBs. For antenna PCB manufacturing-related services, you can contact Maxipcb to obtain professional technical support and solutions.

Product Name: Antenna PCB

Material: Teflon / Ceramic / FR-4

Quality standard: IPC-6012

Dielectric constant: 2.0-16

Layers: 1 Layer - 34 layer

Thickness: 0.254mm - 6.0mm

Copper thickness: H/H-3OZ

Surface technology: Silver(Can choose Gold or OSP)

Application: GPS Antenna PCB, WiFi Antenna PCB, 5G Antenna PCB