4-in-1 combination antenna

　　A 4-in-1 combination antenna is a composite antenna design that integrates multiple wireless communication functions. It is usually used to support multi-band, multi-protocol devices (such as smartphones, IoT devices, drones, vehicle systems, etc.). Here are the key information and suggestions about it:

　　1. Typical functional combination

　　4-in-1 antennas generally cover the following four common wireless communication standards:

　　Wi-Fi (2.4GHz/5GHz)

　　Bluetooth/BLE

　　GNSS (GPS/L Beidou/Galileo)

　　Cellular network (4G LTE/LTE-A/5G NR)

　　2. Core design challenges

　　Frequency band compatibility: The electromagnetic characteristics of different frequency bands need to be covered (low-frequency long wave vs. high-frequency short wave).

　　Space constraints: Miniaturization design (such as inside a mobile phone) needs to balance antenna size and performance.

　　Mutual interference suppression: Avoid signal coupling or harmonic interference between different frequency bands.

　　Multi-protocol coexistence: Ensure the stability of multiple signals when transmitting simultaneously.

　　3. Common implementation schemes

　　Solution 1: Split integration

　　Structure: Combine multiple independent antennas (such as dipoles, loop antennas, and helical antennas) in a compact space through a shared ground or radiator design.

　　Example: The main antenna + diversity antenna + GPS antenna in a mobile phone are integrated in the same module.

　　Solution 2: Multi-band shared radiator

　　Technology: Use the same physical structure to support multiple bands (such as MIMO antenna arrays or wideband antennas).

　　Advantages: Save space and reduce costs.

　　Disadvantages: Need to fine-tune the matching circuit.

　　Solution 3: Flexible/bendable antenna

　　Application scenarios: Wearable devices or embedded devices (such as smart watches, AR glasses).

　　Material: Flexible PCB, metal foil or liquid metal antenna.

　　4. Key components and technologies

　　Antenna type:

　　IFA (Inverted-F Antenna): Suitable for low frequencies (such as 700MHz LTE).

　　PIFA (Planar Inverted-F Antenna): Balance size and bandwidth.

　　Monopole antenna: simple and suitable for multi-band expansion.

　　Dielectric Resonator Antenna (DRA): high-frequency (5GHz+) miniaturized solution.

　　Matching circuit: use LC filter or π-type network to optimize impedance matching.

　　Isolation technology: reduce signal crosstalk through metal partition or electromagnetic shielding.

　　5. Recommended manufacturers and products

　　Enterprise-level solutions:

　　Qorvo: multi-band integrated antenna module (such as support for 5G+Wi-Fi 6E).

　　Pineapple Antenna: ultra-wideband (UWB+GNSS+LTE) combination antenna.

　　Open source/DIY reference:

　　Hackaday project: customized all-in-one antenna design based on 3D printing.

　　6. Design suggestions

　　Clear requirements: determine the target frequency band, power budget and device shape (such as thickness, material).

　　Simulation verification: use HFSS or CST Microwave Studio for electromagnetic simulation to optimize antenna layout.

　　Key test indicators:

　　S parameters (insertion loss, return loss).

　　Radiation efficiency and gain.

　　The impact of multipath effect on GNSS positioning.

　　Cost control: choose mature processes (such as LDS antennas) instead of complex 3D printing.