Are there standard built-in antennas?

　　What type of antenna does "built-in antenna" refer to? It could be one integrated into a device, such as a mobile phone, router, or other electronic device. "Standard parts" might refer to whether there are standardized specifications or readily available modules on the market that can be purchased directly.

　　Common built-in antennas include PCB antennas, ceramic antennas, FPC antennas, and LDS antennas. Different application scenarios may require different antenna types. For example, mobile phones often use LDS antennas, while some IoT devices may use ceramic or PCB antennas.

　　Next, are there standard parts? Typically, many electronic components, such as resistors, capacitors, and connectors, have standardized packages and specifications. However, the situation with antennas can be different, as antenna design is highly dependent on the operating frequency, size, installation environment, and overall device design. For example, while Bluetooth and Wi-Fi antennas both operate around 2.4 GHz, their specific designs can vary depending on the device's structure.

　　However, some vendors do offer standardized antenna modules, such as chip antennas, which may have standardized dimensions and interfaces for easy integration onto circuit boards. Examples include Murata, TDK, and Johanson. Standard ceramic patch antennas manufactured by companies like Intel and Intel Technology typically have fixed dimensions and frequency ranges and can be considered standard parts.

　　Also, antennas with certain connector interfaces, such as PCB antennas or external antennas with U.FL or MMCX interfaces, may have standardized interfaces, but the design of the antenna itself may still need to be adjusted based on the application. However, when users mention internal antennas, they may be referring more to antennas directly integrated into the device, rather than externally connected via a connector.

　　It's important to note that while standardized antenna elements exist, actual applications may require adjustments based on specific circumstances, such as tuning the matching circuit, antenna placement, and interference from surrounding metal parts. Therefore, even when using standard parts, Some customization may also be required.

　　In addition, regarding industry standards, antennas for specific communication protocols (such as Bluetooth, Wi-Fi, and ZigBee) may have corresponding standard requirements, but the physical form of the antenna may still need to be adjusted based on the device design. For example, the Bluetooth SIG may have standards for RF testing, but antenna implementations can vary.

　　Perhaps the user's actual need is to reduce design time and directly purchase off-the-shelf antenna modules, so it's important to recommend some common standard antenna types and suppliers. At the same time, it's important to remind the user that even when using standard components, impedance matching and performance testing are still required to ensure effectiveness in actual applications.

　　To summarize, the answer should include the following points:

　　1. Some standardized internal antennas exist, such as patch antennas, with standard sizes and specifications.

　　2. These standard components are provided by specific manufacturers and are suitable for common frequency bands and protocols.

　　3. In actual applications, matching circuits and layout adjustments may be required, making them not completely plug-and-play.

　　4. When selecting, consider factors such as frequency, size, and mounting method, and refer to the manufacturer's design guidelines.

　　There are indeed some standardized options for internal antennas, especially in common application scenarios and frequency bands. The following is a detailed classification and description:

　　1. Standardized Internal Antenna Types

　　Chip Antenna

　　Features: Small, surface mount (SMD), suitable for PCB integration.

　　Frequency Bands: Covers 2.4 GHz (Bluetooth/Wi-Fi), 5 GHz, GPS, LTE, etc.

　　Flexible Printed Circuit Antenna

　　Features: Flexible, suitable for space-constrained devices. Some manufacturers offer standard shapes (such as square and strip).

　　Applications: Smartwatches, portable devices.

　　Printed Circuit Antenna Antenna

　　Features: Directly etched onto the PCB, such as inverted-F antennas (IFA) and serpentine antennas.

　　Standardization: Some manufacturers provide pre-designed PCB antenna drawings for quick integration.

　　LDS Antenna (Laser Direct Structuring)

　　Features: 3D antennas are formed on a plastic support using a laser. Commonly found in mobile phones.

　　Standardization: Customization is required, but the process itself has industry standards.

　　2. Key Factors in Selecting Standard Components

　　Frequency Range: Ensure coverage of the target frequency band (e.g., 868MHz, 2.4GHz, 5GHz).

　　Size and Mounting Method: Patch antennas must fit within the PCB space, while FPC antennas require consideration of mounting methods.

　　Impedance Matching: Typically designed for 50Ω, but optimization is required through matching circuits (e.g., π-type networks).

　　Certifications and Protocols: Antenna modules certified by Bluetooth BQB and the Wi-Fi Alliance can reduce testing costs.

　　3. Practical Application Considerations

　　Environmental interference: Surrounding metal components or batteries may affect performance, requiring layout adjustments through simulation or actual measurements.

　　Necessary debugging: Even when using a standard antenna, a vector network analyzer (VNA) is required to tune the matching circuit.

　　Manufacturer support: Refer to the reference designs provided by the vendor (e.g., PCB layout recommendations and grounding).