In modern positioning, navigation, and timing (PNT) systems, antijamming GNSS helix antenna has emerged as a core component for reliable satellite signal reception in complex electromagnetic environments. Global Navigation Satellite System (GNSS) signals, including GPS, GLONASS, Galileo, and BeiDou, travel over long distances from orbital satellites to ground receivers, resulting in extremely weak signal strength on the Earth’s surface. These lowpower satellite signals are highly vulnerable to various radio frequency (RF) interference, accidental signal occlusion, and intentional jamming attacks, which often cause GNSS signal loss, positioning drift, or complete system failure. Traditional GNSS antennas, such as patch antennas and rod antennas, struggle to cope with highdensity electromagnetic interference and dynamic working scenarios, making them unable to meet the highreliability PNT requirements of industrial, military, unmanned, and marine equipment.

The antijamming GNSS helix antenna integrates the structural advantages of spiral helix radiation units, highprecision phase center stabilization technology, and professional antiinterference circuit design. Different from ordinary GNSS antennas, it features superior outofband interference suppression, lowelevation signal reception capability, circular polarization stability, and active jamming resistance. It can effectively filter cofrequency interference, outofband electromagnetic noise, multipath reflection signals, and directional jamming signals, maintaining continuous, stable, and centimeterlevel highprecision positioning output in harsh working conditions. This article comprehensively analyzes the working principle, core structure, key performance advantages, mainstream technologies, application scenarios, selection criteria, and industry value of antijamming GNSS helix antennas, providing professional technical references and procurement guidance for global engineering users, equipment developers, and system integrators.

What Is an AntiJamming GNSS Helix Antenna?

An antijamming GNSS helix antenna is a highperformance satellite navigation antenna specially optimized for antiinterference and antijamming capabilities, based on the classic helix antenna structure and upgraded with modern RF circuit design and electromagnetic compatibility (EMC) technology. Unlike conventional helix antennas that only focus on basic signal reception, antijamming GNSS helix antennas are tailored for the vulnerability of GNSS satellite signals, solving core pain points such as weak signal antiinterference ability, poor multipath resistance, and susceptibility to manmade jamming.

Structurally, mainstream antijamming GNSS helix antennas adopt a fourarm spiral helix structure (quadrifilar helix antenna, QHA) or dualhelix differential design, which abandons the singlespiral structure of traditional antennas. This structural innovation enables the antenna to achieve omnidirectional circular polarization reception, stable phase center, and wide beam coverage without relying on a large ground plane. Equipped with a builtin lownoise amplifier (LNA) and highprecision bandpass filter circuit, the antenna realizes highgain signal amplification and strong outofband interference suppression, forming a complete antijamming signal reception system integrating antenna radiation, signal filtering, noise reduction, and antijamming processing.

In terms of functional definition, the core difference between ordinary GNSS helix antennas and antijamming models lies in active and passive jamming suppression capabilities. Ordinary helix antennas only passively receive satellite signals and have no filtering effect on interference signals; while antijamming GNSS helix antennas can suppress groundbased jamming signals, highpower cofrequency interference, multipath reflected signals, and industrial electromagnetic noise through structural optimization and circuit filtering, ensuring effective reception of weak GNSS satellite signals in complex electromagnetic environments.

 Core Working Principle of AntiJamming GNSS Helix Antennas

The excellent antijamming performance of GNSS helix antennas comes from the organic combination of spiral radiation structure characteristics, circular polarization antiinterference mechanism, and active circuit antijamming technology. Its working principle can be divided into three core modules: structural antimultipath interference, polarization antiinterference, and circuit antijamming suppression.

2.1 Helix Structural Multipath Suppression Principle

Multipath interference is one of the most common factors leading to GNSS positioning errors, which is generated by satellite signal reflection from buildings, ground, water surfaces, and vehicles. Traditional patch antennas are highly sensitive to multipath signals, and reflected signals will overlap with direct satellite signals, causing phase center offset and positioning deviation. The helix structure of antijamming GNSS antennas adopts a threedimensional spiral radiation design with symmetrical array layout, which has natural multipath suppression characteristics.

The quadrifilar helix structure used in mainstream products can form a uniform spherical radiation field, effectively distinguishing direct satellite signals from lowangle reflected multipath signals. The antenna’s unique beam shaping technology suppresses the gain of lowangle ground reflected signals below the effective reception threshold, while maintaining high gain for highelevation satellite signals. This structural design greatly reduces the probability of multipath signal coupling, fundamentally improving the positioning stability in urban building clusters, coastal waters, and complex terrain environments.

2.2 Circular Polarization AntiInterference Mechanism

All GNSS satellite signals adopt righthand circular polarization (RHCP) transmission, while most ground interference signals, jamming signals, and multipath reflected signals are linear polarization or lefthand circular polarization (LHCP). The antijamming GNSS helix antenna is precisely designed for RHCP signal reception, with extremely high polarization discrimination ability.

When interference signals with inconsistent polarization characteristics enter the antenna radiation range, the antenna will produce strong polarization attenuation on nonRHCP signals, automatically filtering out most linear polarization electromagnetic noise and reflected jamming signals. Compared with linearly polarized antennas, circularly polarized helix antennas can reduce polarization loss by more than 90% in GNSS signal reception, and effectively resist signal fading caused by antenna attitude tilt, which is especially suitable for dynamic working equipment such as UAVs, vehicles, and ships.

2.3 Active Circuit AntiJamming Suppression Technology

Passive structural antiinterference can solve most natural interference problems, while active circuit antijamming technology is the core to resist intentional jamming and highpower industrial interference. Antijamming GNSS helix antennas are equipped with customized highperformance LNA and narrowband bandpass filter circuits inside the shielded cavity.

The builtin LNA has ultralow noise figure and high outofband rejection capability, which can accurately amplify weak GNSS satellite signals in the L1, L2, L5, B1, B2, E1, and E5 frequency bands, while suppressing outofband interference signals with a suppression depth of up to 20dB or higher. For inband cofrequency jamming signals, some highend models adopt adaptive nulling antijamming technology, which can automatically identify the direction of jamming signals, form signal nulls in the jamming direction, and shield directional jamming interference without affecting the reception of normal satellite signals. This active antijamming mechanism enables the antenna to maintain stable operation in highinterference scenarios such as industrial parks, urban signalintensive areas, and adversarial jamming environments.

 Key Advantages of AntiJamming GNSS Helix Antennas Over Traditional Antennas

In the field of highprecision GNSS positioning, traditional antennas such as patch antennas, rod antennas, and ordinary helix antennas have obvious performance bottlenecks in antiinterference, environmental adaptability, and positioning accuracy. Antijamming GNSS helix antennas have comprehensive performance advantages through structural optimization and technological upgrading, becoming the preferred solution for highreliability PNT systems.

3.1 Excellent AntiJamming and AntiMultipath Performance

Traditional patch antennas have simple structures and no effective interference suppression measures, which are easily affected by surrounding electromagnetic equipment, resulting in frequent signal drift and loss of lock. Ordinary helix antennas only have basic circular polarization characteristics and cannot resist highpower manmade jamming and intensive cofrequency interference. In contrast, antijamming GNSS helix antennas integrate structural multipath suppression, polarization filtering, and circuit active jamming suppression technologies, with outstanding comprehensive antiinterference capabilities.

Test data shows that professional antijamming helix antennas can achieve 15–25dB wideband jamming suppression for lowelevation interference signals, effectively resisting common interference sources such as mobile base stations, industrial frequency converters, RF communication equipment, and intentional signal jammers. In complex urban canyon and mountain terrain scenarios, the multipath error suppression capability is more than 3 times that of ordinary patch antennas, ensuring continuous and accurate positioning data output.

3.2 UltraStable Phase Center and HighPrecision Positioning

Phase center stability is a key indicator affecting GNSS RTK highprecision positioning. Traditional antennas have large phase center offset with the change of signal incidence angle and frequency, resulting in centimeter to decimeter level positioning errors. Antijamming GNSS helix antennas adopt multipoint feeding technology and DQHA differential helix design, realizing ultrahigh phase center stability.

The phase center offset of highquality antijamming helix antennas is controlled within ±0.1mm, which supports centimeterlevel and even millimeterlevel highprecision RTK positioning. Whether the equipment is in static fixedpoint monitoring or dynamic tilt operation, the antenna phase center remains stable, avoiding positioning jitter and drift caused by attitude changes, fully meeting the highprecision positioning requirements of surveying and mapping, autonomous driving, and precision agriculture.

3.3 Wide Beam Coverage and Strong Environmental Adaptability

Most traditional GNSS antennas have narrow beam angles and poor lowelevation signal reception capabilities, which are prone to satellite signal loss in scenarios with terrain occlusion and equipment attitude changes. Antijamming GNSS helix antennas feature a 360° omnidirectional horizontal coverage and ultrawide vertical beam angle, which can stably receive lowelevation satellite signals as low as 5° elevation angle.

This widebeam design enables the antenna to capture more satellite resources, improve satellite tracking quantity and signaltonoise ratio (SNR), and enhance system positioning continuity. In addition, most antijamming helix antennas adopt integrated lightweight and rugged industrial design, with IP67 or above waterproof and dustproof grade, excellent shock resistance, vibration resistance, and temperature resistance, adapting to extreme working environments such as high temperature, low temperature, rain, snow, and strong vibration.

3.4 Compact Size and Easy Integration

Different from largescale CRPA antijamming antenna arrays used in military highend equipment, civilian and industrialgrade antijamming GNSS helix antennas have a compact and lightweight structure, no need for large grounding plates, and low installation space requirements. It can be flexibly integrated into UAVs, unmanned vehicles, marine equipment, handheld surveying instruments, and industrial monitoring terminals, solving the integration difficulty of traditional highperformance antijamming antennas with large volume and heavy weight. While ensuring professional antijamming performance, it realizes miniaturization and lightweight, balancing performance and practicability.

Mainstream Technical Types of AntiJamming GNSS Helix Antennas

With the continuous upgrading of GNSS system technology and the diversification of application scenarios, antijamming GNSS helix antennas have derived multiple technical types, which can be divided by structural form, frequency band coverage, and antijamming level to meet the differentiated needs of military, industrial, and civilian fields.

4.1 Quadrifilar Helix AntiJamming Antenna (QHA)

Quadrifilar helix antenna is the most mainstream structural form of current antijamming GNSS helix antennas. It adopts four symmetrical spiral radiation units with differential feeding, forming a uniform circular polarization radiation field. This structure has the advantages of ultrastable phase center, omnidirectional coverage, and strong multipath suppression. After being matched with highperformance filter LNA circuit, it can effectively suppress outofband interference and lowpower inband jamming, which is widely used in industrial highprecision positioning scenarios such as UAV surveying and mapping, precision agriculture, and vehicle navigation.

4.2 Differential DHelix AntiJamming Antenna

DHelix differential helix antenna is an upgraded version of the traditional quadrifilar helix structure, adopting dualdifferential radiation and multipoint synchronous feeding technology. It further optimizes the antenna beam pattern and phase center stability, with higher gain and stronger antimultipath ability. This type of antenna is equipped with a customized antijamming circuit system, which can resist mediumpower directional jamming and intensive electromagnetic interference, and is mostly used in highprecision RTK positioning, marine navigation, and outdoor industrial monitoring scenarios.

4.3 MultiBand Integrated AntiJamming Helix Antenna

According to frequency band coverage, antijamming GNSS helix antennas are divided into singleband and multiband models. Singleband antennas are mainly for L1 singlefrequency positioning, with low cost and suitable for ordinary civilian navigation. Multiband antijamming helix antennas support fullband reception of GPS L1/L2/L5, BeiDou B1/B2/B3, Galileo E1/E5, and GLONASS G1/G2, covering all mainstream GNSS satellite frequency bands. The multiband design realizes multisystem satellite fusion positioning, improves positioning redundancy and reliability, and the builtin multichannel filtering technology can perform targeted interference suppression for different frequency bands, with stronger comprehensive antijamming performance, which is the mainstream choice of current highend industrial and military equipment.

4.4 MilitaryGrade Nulling AntiJamming Helix Antenna

Militarygrade antijamming helix antennas adopt adaptive nulling antijamming technology and LEANA lowelevation angle nulling technology. They can automatically detect jamming signal sources in the environment, form directional signal nulls to suppress highpower jamming signals, and realize 360° fullspace antijamming protection. This type of product has ultrahigh jamming suppression depth, which can resist professional highpower jammers and adversarial electromagnetic interference, and is mainly used in military vehicles, battlefield PNT equipment, and aerospace navigation systems.

Wide Application Scenarios of AntiJamming GNSS Helix Antennas

Relying on its superior antijamming capability, highprecision positioning performance, and strong environmental adaptability, antijamming GNSS helix antennas have been widely used in military defense, industrial automation, unmanned equipment, marine navigation, surveying and mapping, and many other fields, becoming the core guarantee for reliable PNT services in complex environments.

5.1 UAV Autonomous Navigation and Surveying & Mapping

UAVs work in dynamic flight states, with complex surrounding electromagnetic environments and frequent attitude changes, which put forward extremely high requirements on antenna antiinterference ability and signal stability. Ordinary GNSS antennas are prone to signal loss and positioning offset during UAV flight, affecting flight safety and surveying and mapping accuracy. Antijamming GNSS helix antennas have wide beam coverage, stable circular polarization, and strong antimultipath ability, which can stably track satellite signals during UAV tilting, rotating, and longdistance flight.

At the same time, it can effectively filter electromagnetic interference from UAV flight control modules, power modules, and ground communication equipment, ensuring centimeterlevel RTK positioning accuracy for aerial surveying, mapping, power inspection, and agricultural plant protection UAVs, greatly improving the operational reliability and data accuracy of UAV equipment.

5.2 Intelligent Vehicle and Autonomous Driving

Intelligent connected vehicles and autonomous driving systems need continuous and highprecision GNSS positioning data to realize lanelevel navigation and automatic driving control. Urban road environments are filled with a large number of electromagnetic interference sources such as traffic signal equipment, mobile base stations, and vehicle electronic equipment, and building occlusion and multipath reflection will also seriously affect GNSS signal quality.

Antijamming GNSS helix antennas can suppress urban complex electromagnetic interference and building multipath interference, maintain stable satellite signal reception in urban canyons, tunnels, and dense building areas, and provide highprecision and highreliability positioning data for vehicle automatic driving, intelligent parking, and fleet management systems, ensuring driving safety and control accuracy.

5.3 Marine and Offshore Navigation Monitoring

Marine working environments have complex electromagnetic conditions, and sea surface reflection will produce a large number of multipath interference signals. At the same time, offshore communication equipment, ship electronic systems, and coastal industrial equipment will generate continuous electromagnetic interference, leading to unstable GNSS signals of ships and offshore monitoring equipment. Antijamming GNSS helix antennas have excellent seaadapted antimultipath performance and highintensity interference suppression capability, with waterproof, saltfog resistant, and corrosionresistant industrial grade design.

They are widely used in ship navigation, offshore buoy monitoring, marine unmanned ship positioning, and offshore engineering equipment positioning, ensuring longterm stable operation of PNT systems in harsh marine environments and avoiding navigation errors and equipment failures caused by signal interference.

5.4 Military Defense and Special Equipment

In battlefield environments, enemy electromagnetic jamming, radar signals, and communication interference will completely cover ordinary GNSS signals, resulting in the failure of traditional positioning systems. Militarygrade antijamming GNSS helix antennas adopt adaptive nulling antijamming technology, which can effectively resist intentional manmade jamming and strong electromagnetic interference, maintain normal GNSS positioning and timing functions of military vehicles, battlefield terminals, and aerospace equipment, and provide reliable PNT support for military operations.

5.5 Precision Agriculture and Industrial Monitoring

Modern precision agriculture relies on highprecision GNSS positioning to realize automatic sowing, fertilization, and pesticide spraying operations. Farmland environments are often accompanied by interference from agricultural machinery equipment and highvoltage power facilities. Industrial outdoor monitoring equipment needs longterm stable positioning data in complex electromagnetic environments such as industrial parks and mining areas. Antijamming GNSS helix antennas can filter industrial electromagnetic noise and random interference signals, provide continuous centimeterlevel positioning support for intelligent agricultural machinery and industrial monitoring terminals, and improve the automation and accuracy of industrial and agricultural operations.

Professional Selection Criteria for AntiJamming GNSS Helix Antennas

To select a suitable antijamming GNSS helix antenna, it is necessary to comprehensively evaluate key parameters such as antijamming level, frequency band coverage, phase center stability, gain performance, and environmental adaptability according to actual application scenarios, so as to avoid performance mismatch and waste of costs.

6.1 AntiJamming Performance Parameters

Antijamming capability is the core index of the antenna. Users need to focus on two key parameters: outofband rejection and inband jamming suppression depth. Industrial conventional scenarios require outofband rejection greater than 20dB and inband interference suppression greater than 15dB; highinterference scenarios such as urban intensive electromagnetic environment and industrial parks need to select products with rejection depth above 25dB; military and antijamming special scenarios need to support adaptive nulling antijamming function and ultrahigh jamming suppression capability.

6.2 Frequency Band and Constellation Compatibility

For ordinary singlefrequency positioning scenarios, L1 singleband antijamming helix antennas can meet the demand with low cost. For highprecision RTK positioning and multisystem fusion positioning scenarios, it is necessary to select fullband multiconstellation antennas supporting GPS, BeiDou, Galileo, and GLONASS to improve satellite reception quantity and positioning reliability. It is necessary to confirm that the antenna covers all required frequency bands such as L1/L2/L5, B1/B2/B3 to avoid positioning function limitations caused by missing frequency bands.

6.3 Phase Center Stability and Gain

Highprecision positioning scenarios must focus on phase center offset parameters. Centimeterlevel RTK positioning requires the phase center offset to be less than ±0.5mm, and millimeterlevel positioning needs to be controlled within ±0.1mm. The antenna gain should be moderate, usually 2.5–3.5dBi, which can balance signal reception strength and antiinterference ability. Excessively high gain will amplify interference signals, and excessively low gain will lead to weak satellite signal reception.

6.4 Environmental Adaptability and Structural Size

Outdoor and mobile equipment needs to select antennas with IP67 and above waterproof and dustproof grade, wide temperature working range (40℃～+85℃), and shock and vibration resistance. UAV and handheld equipment with strict size and weight restrictions need to prioritize compact lightweight miniaturized antijamming helix antennas; fixed industrial monitoring and marine equipment can select standard highstability models with stronger structural robustness.

Industry Development Trends of AntiJamming GNSS Helix Antennas

With the rapid development of Beidou global networking, autonomous driving, unmanned systems, and military electromagnetic countermeasure technology, the market demand for antijamming GNSS helix antennas is showing a rapid growth trend, and the industry is developing towards miniaturization, intelligent antijamming, multifunctional integration, and highprecision customization.

First, intelligent adaptive antijamming has become the core development direction. Traditional fixed filtering antijamming technology can only suppress fixedfrequency interference, while the new generation of antijamming helix antennas integrates intelligent algorithm chips, which can realize realtime monitoring of environmental interference, automatic identification of jamming types, and adaptive adjustment of filtering parameters and nulling directions, with more flexible and efficient antijamming performance.

Second, miniaturization and lightweight integration are further upgraded. With the miniaturization of unmanned equipment and portable terminals, highperformance antijamming antennas are breaking the limitation of large volume of traditional antijamming equipment, realizing the integration of antenna radiation unit, LNA filter, antijamming processing module, and power management system in a tiny space, maintaining militarygrade antijamming performance while achieving ultralight and ultrathin structural design.

Third, multiscenario customized differentiation development. Aiming at the differentiated needs of UAV, vehicle, marine, military, and industrial scenarios, manufacturers are launching customized antijamming helix antennas with targeted performance optimization, realizing precise matching of scenario characteristics and antenna performance.

Fourth, low power consumption and high reliability iteration. For portable and batterypowered equipment, lowpower antijamming circuit design has become an important technical iteration direction, which reduces equipment energy consumption while ensuring antijamming performance, and improves the continuous working time of terminal equipment.

As the key core component of highreliability GNSS positioning systems in complex electromagnetic environments,antijamming GNSS helix antenna solves the industry pain points of weak antiinterference ability and poor stability of traditional GNSS antennas through unique helix structure design, circular polarization antiinterference mechanism, and active circuit antijamming technology. It has irreplaceable performance advantages in multipath suppression, jamming resistance, highprecision positioning, and environmental adaptability, and is widely used in unmanned equipment, intelligent transportation, marine navigation, military defense, and industrial monitoring fields.

In the era of rapid development of intelligent navigation and unmanned technology, the stability and accuracy of GNSS positioning directly determine the operational safety and work efficiency of various intelligent equipment. Choosing a highperformance antijamming GNSS helix antenna can effectively avoid positioning failures caused by electromagnetic interference and jamming, and provide solid and reliable PNT basic guarantee for all kinds of highprecision positioning systems. With the continuous progress of antenna technology and antijamming algorithms, antijamming GNSS helix antennas will develop towards higher precision, stronger antijamming ability, and more intelligent integration, and play a more important role in the global highprecision navigation and positioning industry.