Why is it that in various navigation devices, as long as the positioning function is turned on, one can quickly obtain their own location? This cannot be achieved without a key component: GNSS antenna. By capturing weak signals from navigation satellites, GNSS antennas provide real-time and accurate geographic location services for people. Next, we will delve into the background, working principles, classification, applications, design points, and future development directions of GNSS antennas from multiple dimensions, to help readers interested in the navigation field fully understand this important device.
1、 Background and Importance of GNSS Antennas
What is GNSS?
GNSS stands for Global Navigation Satellite System, representing a series of systems that can provide global or regional satellite navigation services. Common ones include GPS from the United States, GLONASS from Russia, Galileo from Europe, and Beidou system from China. GNSS can provide precise temporal and spatial coordinates to users worldwide, allowing people to obtain accurate coordinates in most areas of the Earth.
The role of GNSS antenna in it
To receive and process weak RF signals sent from satellites hundreds of kilometers or even farther away, a professional and sensitive antenna system is required. The main task of GNSS antennas is to capture navigation satellite signals from various directions and convert modulated radio frequencies into electrical signals that can be processed by the receiver. It needs to capture navigation information from multiple constellations and frequency bands, while ensuring sufficient anti-interference ability to achieve stable and accurate positioning.
Why is GNSS antenna so critical?
The strength of navigation satellite signals is low, and environmental noise and multipath interference can both lead to reception failure. If there is no antenna design with high gain, low noise, and good directionality, even if the device has advanced solving algorithms, it is difficult to obtain reliable positioning results. Due to the rise of miniaturized portable devices, GNSS antennas not only need to have excellent performance, but also need to consider size, cost, and structural design to enable stable operation in various scenarios such as handheld terminals, vehicles, and drones.

2、 Working principle and signal characteristics
Signal frequency band and polarization mode
GNSS satellites mostly use the L-band (1-2GHz range) to transmit signals, and different systems and frequency bands have their own bandwidths and characteristics. For example, GPS commonly uses L1, L2, and L5 frequency points, while Beidou has expanded to include B3 in addition to B1 and B2. GNSS antennas are generally designed with right-handed circular polarization (RHCP) to match the polarization of satellite signals, enhance the ability to receive target signals, and reduce the reception of linear or left-handed circular polarization interference, thereby improving signal quality.
The impact of multipath and interference
In complex environments such as densely populated urban buildings or valleys, GNSS signals are prone to reflection and refraction, resulting in multipath signal interference at the receiver end. To address this issue, GNSS antennas typically adopt specific designs to suppress reflections in the low elevation range. In addition, by optimizing the directional pattern of the antenna, high-altitude direct signals are collected with optimal gain, while maintaining a certain attenuation of reflected signals at horizontal or lower elevation angles, reducing the impact of multipath.
Low noise amplifier (LNA) and filtering
In order to prevent weak satellite signals from being overwhelmed in transmission lines, GNSS antennas often have built-in or external low-noise amplifiers (LNAs). LNA can amplify extremely small RF signals and combine with filtering modules to filter out powerful interference sources unrelated to GNSS, maximizing the retention of effective data and providing cleaner signal input to the backend receiver.
3、 Classification of common GNSS antennas
spiral antenna
Characteristics: Generally characterized by four or more arm spiral structures, used for miniaturized products; The circular polarization characteristic is excellent, and the signal reception in the upper and lower airspace is relatively balanced.
Application: Handheld devices, wearable terminals, and other scenarios that require strict volume requirements.
microstrip patch antenna
Features: The resonant structure is composed of metal patches and flooring, with a square and flat shape that is easy to mass produce; Usually installed on a flat platform, it can be manufactured with a plastic shell and ceramic substrate, making it easy to integrate into various electronic products.
Application: Widely used in car navigation, drones, and industry terminals, it has the advantages of low cost, adjustable size, and easy processing.
Flat panel or array antenna
Characteristics: By combining multiple unit arrays, directional or high gain beams are formed, which is very suitable for application scenarios with high signal sensitivity requirements; It can achieve good multi-path suppression at the hardware level.
Application: Professional fields such as surveying, precision agriculture, and ground reinforcement stations that require high-precision positioning or long-term tracking.
The distinction between active and passive
Active antenna: Built in LNA and filter, can be directly connected to antenna cables, reducing signal strength reduction caused by cable loss; Commonly used when there is a high demand for overall device performance.
Passive antenna: relatively simple structure, only for signal capture and transmission, with lower volume and cost; Suitable for scenarios with low signal amplification requirements or where the receiver already has sufficient amplification capability.
4、 Factors affecting structure and performance
Size and appearance
The shape and size of GNSS antennas directly determine the resonance characteristics and gain distribution. To meet the appearance requirements of different devices, it may be necessary to optimize the geometric structure of the antenna. For example, patch antennas may be used in ultra-thin terminals, relying on coin sized ceramic substrates to achieve multi frequency resonance. To cover more frequency bands, it is often necessary to increase the area or adopt more complex structures to ensure good gain and matching in each frequency band.
Antenna Pattern
GNSS antennas need to maintain a relatively uniform gain over a wide range of elevation angles to receive satellite signals from different directions. The directional pattern mainly depends on the shape of the antenna itself and the internal matching method. When designing, we will take into account both the sky view and ground reflection suppression, attenuate the gain in low elevation areas, and ensure the optimal gain at high elevation angles (direct signals). This directional allocation can significantly improve positioning accuracy and anti-interference ability.
Dielectric materials and manufacturing processes
Different dielectric materials (such as ceramics, PCB substrates, plastics, etc.) have different effects on the propagation characteristics of electromagnetic waves. The dielectric constant, dielectric loss, and conductivity of the metal layer will all change the resonant frequency and gain of the antenna to a certain extent. To improve mass production consistency, it is necessary to strictly control the manufacturing process to ensure that each antenna has predictable performance in terms of resonant frequency and bandwidth.
Installation environment and metal shielding
GNSS antennas are often installed on vehicles, drones, or other devices, and the surrounding metal or high dielectric materials may cause disturbances to the antenna pattern and actual gain. The correct installation position, floor design, and avoidance of obstructions play a crucial role in performance. Sometimes it is necessary to specifically design the floor size or specific cover to avoid excessive signal attenuation or severe interference.
5、 Differences in application areas and requirements
Car navigation and advanced assisted driving
Requirement focus: The environment during vehicle operation is complex, and there are high requirements for antenna multipath suppression, real-time positioning update rate, and accuracy. Car mounted antennas are often built into the roof or rearview mirror, requiring good weather resistance and adaptability to various vibration impacts.
Typical case: The intelligent driving system receives positioning data through GNSS antennas and integrates it with inertial navigation or map data to ensure lane level positioning of vehicles on highways.
Drones and Surveying Industry
Requirement focus: In order to achieve precise aerial surveying and terrain mapping, GNSS antennas on drones usually require small and lightweight size, as well as high-precision and high update rate positioning capabilities.
Typical case: When a professional surveying drone performs tasks in the target airspace, the GNSS antenna will cooperate with a differential positioning system or RTK (real-time dynamic differential system) to greatly improve coordinate accuracy and meet centimeter or sub meter level positioning requirements.
Handheld terminals and wearable devices
Requirement focus: In portable devices such as smartphones and smartwatches, size and power consumption are the main limitations, while also ensuring the aesthetic appeal of the design. High integration and power efficiency requirements have been put forward for antennas, requiring multi band reception in extremely limited space.
Typical case: Users use mobile navigation or sports wristbands to record their running trajectories, relying on the stable signal reception capability of GNSS antennas.
High precision applications and professional scenarios
Key requirements: Ground augmentation stations, precision agriculture, survey engineering, and other fields all require all-weather and continuous monitoring of GNSS signals to achieve high-precision positioning and timing. Array or high gain antennas are usually used, combined with protective covers to resist wind and rain erosion in natural environments.
Typical case: Deploying reference station antennas on offshore oil platforms or remote areas to achieve real-time and accurate coordinate reference, providing reliable support for various measurement and positioning tasks.
6、 Key points of design and selection
Multi band coverage
Modern navigation devices often need to receive signals from multiple constellations and frequency bands, such as GPS L1/L2, Beidou B1/B2, etc., to improve positioning stability. The antenna needs to be designed to simultaneously consider multiple frequency resonance points and ensure that each frequency band has reasonable bandwidth and gain. Otherwise, once a certain constellation or frequency band signal is insufficient, the overall positioning may experience a decrease in accuracy or loss of lock.
Impedance matching and gain balancing
GNSS antennas need to maintain efficient energy coupling with backend receivers and transmission lines, typically matched with a reference impedance of 50 ohms. If the matching is poor, it will lead to an increase in return loss and a decrease in actual sensitivity. To achieve the most balanced directional pattern, it is necessary to adjust the antenna installation angle and position according to the actual usage scenario.
Durability and environmental adaptability
Outdoor equipment is subject to changes in temperature, humidity, vibration, and electromagnetic environment, therefore the thermal stability, mechanical strength, and protection against static electricity or lightning strikes of antenna materials should be considered in the design. Most GNSS antennas need to have a certain level of waterproof and dustproof performance, and maintain stable resonance points even at extreme temperatures, without excessive frequency deviation or sudden gain drops.
Cost and feasibility of mass production
For large-scale commercial markets, manufacturing costs and mass production processes are key considerations. Microstrip patch antennas are the mainstream choice for many mid to low price products due to their mature mass production and relatively controllable cost. High end surveying grade or large-sized array antennas, although expensive, can provide higher accuracy and better anti-interference performance, suitable for professional and industry level markets.
7、 Debugging, testing, and optimization
Indoor darkroom testing
Evaluating the directional pattern and gain of GNSS antennas requires the use of specialized testing equipment in an anechoic chamber to measure the radiation intensity at different elevation and azimuth angles. This can quantify antenna performance and promptly identify issues such as uneven directional patterns and insufficient bandwidth during the initial development phase.
Field measurement and comparison
Laboratory data alone is not sufficient to fully reflect the signal performance of the real environment. After the design is completed, it is usually necessary to conduct outdoor or real-life comparative tests, such as city blocks, highways, forest areas, etc. By recording the number of visible satellites, signal-to-noise ratio, positioning drift, etc., the actual optimization space of the antenna in different environments can be found.
Software simulation and iterative design
In modern R&D processes, electromagnetic simulation software (such as HFSS, CST) is often used to simulate antenna structures and directional patterns. Developers can make various modifications during the simulation phase, observe the impact of geometric and material changes on performance, and thereby reduce the number of repeated processing times for physical prototypes, greatly improving iteration efficiency.
8、 Future Development and Prospects
Higher frequency band and wider bandwidth
With the introduction of new generation navigation systems and signal modes, GNSS may introduce more or higher frequency bands in the future to cope with more complex environments and more precise application requirements. Antenna design will also evolve towards multi frequency broadband, covering more frequency resources simultaneously in the same or smaller volume.
Intelligent and deformable antenna
With the rise of wearable devices and unmanned systems, flexible or foldable antennas may become a trend. Combined with intelligent control circuits, the antenna may be able to achieve adaptive directional pattern adjustment, automatically selecting the optimal beam direction, allowing the positioning system to perform excellently in different scenarios.
Integration and multifunctional fusion
For modern electronic products, a standalone GNSS antenna often needs to have functions such as Wi Fi, Bluetooth, cellular communication, etc. The design of integrated antenna modules will further enhance product integration and performance, reduce the potential for interference between multiple antennas, and simplify external structural design.
High precision and indoor positioning compensation
As the demand for positioning accuracy continues to increase, the trend of combining GNSS with inertial navigation and ground station signals will become more apparent. Antennas may not only be responsible for receiving satellite signals in the future, but also achieve near real-time centimeter level accuracy through multi-mode and multi frequency fusion. Further improved antenna technology can provide a better positioning experience for indoor and underground scenes, promoting the expansion of application boundaries.