fiberglass mobile car antenna

　　The following is a detailed analysis of the fiberglass vehicle-mounted mobile antenna, covering its principles, design features, typical applications and selection recommendations:

　　1. Core features and advantages

　　Material characteristics:

　　Lightweight: low density (about 1.5~2.5g/cm³), reducing the burden on the vehicle.

　　High strength: impact resistance, corrosion resistance (acid and alkali resistance, UV resistance), suitable for complex climate environments.

　　Low dielectric loss: high efficiency of high-frequency signal transmission (suitable for FM/AM, GNSS, satellite communications).

　　Antenna performance:

　　Wideband support: covers frequency bands such as 530–1750kHz (AM/FM broadcast) and 1.575GHz (L1 GNSS).

　　Moderate gain: typical gain 3–8dBi, balanced signal reception and installation convenience.

　　Anti-multipath interference: reduce signal reflections in urban canyons or mountainous areas by optimizing the antenna direction angle.

　　2. Typical application scenarios

　　In-vehicle radio reception:

　　Supports FM/AM FM radio, improving the listening quality in weak signal areas (such as tunnels and mountainous areas).

　　Satellite navigation system:

　　Integrated GNSS antenna function for in-vehicle navigation and track recording (requires receiving module).

　　Emergency communication:

　　Applicable to walkie-talkies, satellite phones and other scenarios (requires additional RF front end).

　　Modified cars and RVs:

　　Adapt to mobile scenarios such as off-road vehicles and RVs to meet the needs of long-term outdoor use.

　　3. Mainstream types and comparison

　　Antenna type Features Applicable scenarios

　　Whip fiberglass antenna - Length 0.5~1.2 meters, directly installed on the roof or window.

　　Compatible with FM/AM radio and GNSS. | Urban commuting, short and medium-distance driving |

　　| Spiral fiberglass antenna | - Curled structure, high gain (≥5dBi), supports multiple frequency bands.

　　Can be integrated into the luggage rack or headlights. | Long-distance travel, weak signal environment |

　　| Magnetic fiberglass antenna | - Adsorbed on the roof or hood through a magnetic base.

　　Portable and easy to install, but with low gain (about 3dBi). | Temporary use or modified car |

　　| Embedded fiberglass antenna | - Built into the car body (such as doors, roof interior), highly concealed.

　　Requires customized design. | Factory pre-installed or high-end car modification |

　　4. Design points

　　4.1 Material selection

　　Fiberglass substrate:

　　Epoxy resin base: low cost, mature process, suitable for normal temperature environment.

　　Polyester resin base: better high temperature resistance (>150℃), suitable for near the engine compartment.

　　4.2 Structural design

　　Radiator shape:

　　Straight whip antenna: simple and reliable, suitable for low frequency band (AM/FM).

　　Folding or telescopic design: easy to store, avoid taking up space (such as shrinking when parking).

　　Feeder matching:

　　Use 50Ω coaxial cable to connect the car radio or navigation system to reduce signal attenuation.

　　4.3 Anti-interference measures

　　Shielding design:

　　Wrap the antenna root with copper foil or metal shielding sleeve to isolate the electromagnetic noise of the vehicle body.

　　Grounding optimization:

　　Ensure that the antenna ground terminal is well grounded with the vehicle body (resistance < 0.1Ω).

　　5. Installation precautions

　　Location selection:

　　Center of the roof: Stay away from metal parts (such as window frames, luggage racks) to reduce signal shielding.

　　Behind the hood: Avoid high temperature radiation (at least 30cm away from the engine).

　　Feeder wiring:

　　Shorten the feeder length (≤5 meters), and give priority to low-loss cables (such as RG-58/U).

　　Avoid parallel layout of the feeder with the fuel line and high-voltage harness.

　　Regulatory compliance:

　　Some regions restrict antenna height (such as ≤1.5 meters in the United States), which needs to be confirmed in advance.