Figure 1 Standard stacked patch antenna compared to the Taoglas Inception HP5354.A.

Figure 2 Peak gain for L1-B1-E1-G1 and L5.

Taoglas’ Inception HP5354.A “patch-in-a-patch” antenna exemplifies a forward-thinking approach to antenna design. The HP5354.A is a passive GNSS L1/L5 antenna offering dual-band stacked patch performance in a standard 35 × 35 × 4 mm form factor. By recessing the second antenna within the first, Inception reduces antenna height by 50 percent and decreases weight, making it an ideal solution for the demanding precision and accuracy of GNSS applications with limited space. Figure 1 illustrates a standard stacked patch antenna as compared to the HP5354.A.

The patent-pending HP5354.A is a drop-in replacement for single-band surface-mount patches, improving the IoT device’s positioning accuracy from over 3 meters to 1.5 meters without compromising the dual-band L1/L5 performance.

ANTENNA PERFORMANCE AND KEY SPECIFICATIONS

The HP5354.A has a passive peak gain of 2.61 dBi optimized for GPS L1/ L5, BeiDou B1, Galileo E1 and GLONASS G1 operation with the next generation of dual-band GNSS receivers on the market. Figure 2 displays the peak gain for L1-B1-E1-G1 and L5.

Key product specifications include:

• Band coverage: GPS L1/L5, GLONASS G1, Galileo E1/E5a, BeiDou B1/B2a
• Frequency range: 1160 to 1610 MHz 
• Maximum gain: 2.61 dBi 
• Tight phase center variation (PCV): < 0.02 cm
• Polarization: right hand circularly polarized (RHCP) 
• Material: ceramic
• Dimensions: 35 x 35 x 4 mm
• Weight: 16 g.

Figure 3 shows a Taoglas anechoic chamber used to test the radiation patterns on a 70 mm × 70 mm ground plane. Figure 4 shows the radiation patterns at 1176 MHz. The radiation patterns at 1561 MHz, 1575 MHz and 1602 MHz can be found in the product datasheet.

Figure 3 Anechoic chamber test setup.

Figure 4 Radiation patterns at 1176 MHz.

SUPPORTS INDUSTRY’S TRANSITION FROM L1 TO L5

Applications such as asset tracking, smart agriculture, industrial tracking, commercial drones and autonomous vehicles require better stability, resilience and precision. For decades, the industry has used single-band GPS, but emerging bands such as L2, L5, L6 and L-Band offer system designers a path to cleaner signals, improved gain and cm-level accuracy. The same trend applies to global GNSS technologies, including GPS, GLONASS, Galileo, BeiDou, QZSS, IRNSS and SBAS. The L5 band utilized by the HP5354.A has a higher signal strength that is less susceptible to interference and ionospheric distortion, so when combined with the L1 signal, it allows for better error correction, which leads to more precise positional accuracy.

Inception’s unique design allows customers to integrate a multi-band L1/L5 GNSS patch into devices where this would not have been possible before due to height constraints. Instead of using two patch antennas, a single HP5354.A antenna can be used. At only 4 mm in height, the HP5354.A can be used in various applications where typical stacked patch designs are too tall. Weighing only 16 g, the HP5354.A can reduce the overall system weight, which may increase battery life in some applications.

For applications with stringent system-level requirements, like automotive and space, Taoglas meets various customer surface-mount reflow profiles, resulting in very secure mounting on customer printed circuit boards (PCBs). This secure mounting helps minimize shock and vibration issues. Additionally, the dual-feed design helps maintain circular polarization gain in cases where the antenna has been detuned and/or needs to be tuned in situ. This improves multipath rejection over the entire antenna bandwidth for improved timing and cleaner signals. It also improves axial ratio bandwidth, helping reject multipath signals and enhancing navigation accuracy.

USES A CUSTOM ELECTROCERAMICS FORMULA

The Taoglas surface-mount antenna technology is designed using a custom electroceramics formula. This ensures high-quality performance and seamless integration into devices requiring high-precision GNSS. Instead of using off-the-shelf formulas, Taoglas uses its in-house design and manufacturing capabilities to optimize its electroceramic mix, delivering robust performance for high-reliability applications.

ANTENNA INTEGRATION WITH SUPPORTING PRODUCTS

The HP5354.A has three feeds. Two feeds are used for the L1 band and the other for the L5 band. The Taoglas HC125A hybrid coupler can combine the dual feeds for the L1 patch, offering high RHCP gain and optimal axial ratio for upper constellations, including GPS L1, BeiDou B1, Galileo E1 and GLONASS G1.

Active circuitry needs to be upgraded to L1/L5 along with the antenna. The Taoglas TFM.100B L1/L5 front-end module can be designed onto the device PCB alongside the antenna to reclaim valuable real estate and save designers up to two years of complex design. The module features a SAW/LNA/SAW/LNA topology in both the low- and high-band signal paths to prevent unwanted out-of-band interference from overdriving the GNSS LNAs or receiver. The SAW filters have been carefully selected and placed to provide excellent out-of-band rejection while maintaining a low noise figure.

Taoglas
San Diego, Calif.
www.taoglas.com