The antenna operates within a frequency band of 1560-1602 MHz, a range carefully selected to cover the core frequencies of major GNSS constellations essential for RTK:

GPS L1 (1575.42 MHz): The primary civilian frequency, offering global coverage and serving as the backbone of most RTK systems.

BeiDou B1 (1561.098 MHz): Enhances coverage in the Asia-Pacific region, adding redundancy and improving satellite visibility in challenging environments.

GLONASS G1 (1602 MHz): Strengthens performance in high-latitude regions, where GPS signals may be weaker, ensuring global RTK reliability.

This multi-constellation support is a cornerstone of RTK accuracy, as it increases the number of visible satellites, reduces the risk of signal blockages, and enables cross-constellation error correction. For example, in urban canyons where GPS signals are obstructed by skyscrapers, BeiDou or GLONASS signals captured by the antenna can maintain RTK lock, ensuring uninterrupted high-precision positioning. This versatility makes the antenna suitable for global applications, from European smart cities to Asian logistics hubs.

The antenna delivers a typical gain of 1.5 dB, a specification that reflects its efficiency in converting received signal energy into usable power for RTK processing. While this gain may seem modest compared to larger external RTK antennas (which often offer 5-8 dB gain), it is optimized for the antenna’s compact size and built-in constraints. Excessive gain in small antennas can narrow the radiation pattern, limiting reception from low-elevation satellites—a critical drawback in RTK, where all available satellites contribute to positioning accuracy. The 1.5 dB gain ensures a broad radiation pattern, allowing the antenna to capture signals from satellites across elevations as low as 10 degrees, which is essential for maintaining RTK lock in urban or forested environments.

This gain is achieved through meticulous design of the ceramic patch’s dimensions and its interaction with the FR4 ground plane. The ceramic’s high dielectric constant focuses energy without overcome narrowing the beam, while the ground plane ensures that radiation is directed upward, minimizing absorption by the device’s housing. In RTK terms, this translates to a higher number of tracked satellites and more robust carrier-phase measurements, both of which are critical for achieving centimeter-level accuracy.

The antenna’s VSWR (Voltage Standing Wave Ratio) specifications—2.0 at 1575 MHz and 3.5 at 1602 MHz—reflect its optimized performance across its frequency band. VSWR measures how efficiently the antenna transfers energy to the receiver, with lower values indicating better matching. At 1575 MHz (GPS L1), a VSWR of 2.0 is excellent, ensuring that over 90% of the received signal is transferred to the RTK receiver with minimal reflection. This is critical for preserving the integrity of GPS L1 signals, which are the primary input for most RTK systems.

At 1602 MHz (GLONASS G1), the higher VSWR of 3.5 is acceptable given GLONASS’s supplementary role in many RTK setups. This tradeoff allows the antenna to maintain a compact size while still providing functional GLONASS reception, ensuring that the system can leverage multiple constellations when needed. For RTK, which relies on redundant satellite data to resolve ambiguities, this balance between GPS performance and multi-constellation support is essential.

With an impedance of 50 ohms, the antenna adheres to the industry standard for RF systems, ensuring seamless compatibility with RTK receivers, GNSS modules, and coaxial cables. Impedance matching is critical for RTK, as mismatched impedances can cause signal reflections that corrupt the carrier-phase measurements used for high-precision positioning. A 50-ohm impedance is universally adopted in GNSS and RTK hardware, allowing the antenna to integrate with off-the-shelf receivers from leading manufacturers. This compatibility simplifies the design process for OEMs, enabling them to pair the antenna with proven RTK chipsets without custom matching networks—a key advantage in reducing development time and costs.

The antenna’s operating temperature range of -20°C to +85°C and storage temperature range of -20°C to +65°C ensure reliable performance in the diverse environments where RTK systems are deployed. From freezing agricultural fields to sun-baked construction sites, the antenna’s components are engineered to withstand extreme temperatures without degradation. The ceramic patch’s dielectric properties remain stable across this range, preventing shifts in resonant frequency that could disrupt RTK lock. The FR4 PCB and IPX connector also resist thermal stress, ensuring mechanical integrity even after repeated temperature cycles.

This temperature resilience is particularly important for built-in RTK antennas, which are often enclosed in device housings where heat from processors or batteries can raise internal temperatures. By maintaining performance up to 85°C, the antenna ensures that RTK accuracy is preserved even in high-power devices such as drone flight controllers or industrial robots operating in warm environments.

With a size of 25 x 25 x 4mm, the antenna sets a new standard for miniaturized RTK technology. This compact footprint allows it to be integrated into devices where traditional RTK antennas—often 50mm or larger in diameter—would be impractical. For example, in a compact drone designed for precision agriculture, the antenna fits within the drone’s body without increasing drag or weight, preserving flight time while enabling centimeter-level mapping. In a wearable RTK tracker for surveyors, the small size ensures comfort without sacrificing accuracy.

The 4mm thickness is equally critical, allowing the antenna to be embedded in slim devices such as tablet-based field mapping tools or IoT sensors mounted on infrastructure. Despite its size, the antenna’s design ensures that the ceramic patch has sufficient surface area to maintain the radiation efficiency required for RTK, proving that high precision does not have to come at the cost of form factor.

The antenna is equipped with an RF1.37mm coaxial cable, 100mm in length, a design that balances flexibility and signal integrity for RTK applications. The 1.37mm diameter cable is thin enough to be routed through the tight spaces of embedded devices, avoiding interference with other components while ensuring a direct path from the antenna to the RTK receiver. The 100mm length is carefully chosen to minimize signal loss—critical for RTK, where even 0.5 dB of additional loss can reduce the number of trackable satellites.

The cable’s braided copper shield provides 90%+ coverage, protecting the weak GNSS signals from electromagnetic interference (EMI) generated by nearby electronics such as motors, displays, or processors. EMI is a significant threat to RTK performance, as it can corrupt carrier-phase measurements and introduce positioning errors. By shielding the signal path, the cable ensures that the RTK receiver receives a clean input, enabling it to resolve ambiguities and maintain centimeter-level accuracy.