Antennas for Iridium STL PNT Signal and for GNSS-Based Timing - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design

Antennas for Iridium STL PNT Signal and for GNSS-Based Timing

Tallysman Wireless introduced two lightweight, compact active Iridium helical antennas: the housed HC610 and the embedded HC610E. They receive the Iridium Satellite Time and Location (STL) signals,  used by STL terminals to provide worldwide position, navigation, and timing independent of GPS/GNSS via an encrypted satellite broadcast signal that is strong, secure and can also be received indoors.  STL signals present an alternative to augment and authenticate time for applications, such as electrical grids, wireless communications networks, and financial systems, as well as position for private and public infrastructure.

The HC610 and HC610E are active Iridium antennas that operate in receive-only mode and enable Iridium terminals to be installed tens of meters away from the antenna. The antennas feature a precision-tuned helical element that provides an axial ratio and operates without a ground plane. They also feature a low-current, low-noise amplifier (LNA) and pre-filter to prevent harmonic interference from high-amplitude signals, such as 700 MHz band LTE and other nearby in-band cellular signals.


The housed HC610 (24 g) is 33 mm wide and 54.2 mm tall and features an IP67, robust, military-grade plastic enclosure, with a base-mounted male SMA connector and two screw holes for surface attachment.


The embedded HC610E (10 g) is 27.5 mm wide and 38.7 mm tall and can be installed in a custom enclosure. It provides a base-mounted female MCX connector. An optional embedded helical mounting ring is available to attach the antenna to a flat surface.

Smart GNSS Timing Antenna

Tallymatics Inc., an associate company, announced the TW5382 Smart GNSS Antenna for High-Accuracy 5G Timing. The TW5382 is a multi-band, multi-constellation 5G smart GNSS antenna/receiver that provides 5 ns (1-

sigma, clear sky view) timing accuracy. The TW5382 consists of two components: a Tallysman GNSS Accutenna technology antenna and a professional-grade GNSS timing receiver module.

The Accutenna technology supports the full bandwidth of the TW5382 receiver, strong multipath mitigation and deep filtering, in a compact IP69K enclosure. These features enable the antenna to provide a strong, pure, in-band, right-hand circular polarized signal to the receiver.

The TW5382’s professional-grade multi-constellation and multi-signal timing receiver tracks GPS/QZSS (L1/L2), GLONASS (G1/G2), Galileo (E1/E5b), and BeiDou (B1/B2) signals. Dual-frequency GNSS enables the receiver to minimize ionospheric delay and enhances multipath mitigation. Other key features of the GNSS receiver include support for anti-jamming and anti-spoofing, Timing-Receiver Autonomous Integrity Monitoring (T-RAIM), and GNSS augmentation systems: WAAS (USA), EGNOS (Europe), MSAS (Japan), and GAGAN (India), all of which provide orbit and clock corrections, a well as health and integrity information.

Multi-constellation tracking enables the GNSS receiver to report the Coordinated Universal Time (UTC) estimated by each constellation. The receiver can be configured to output either the GPS, GLONASS, Galileo, or BeiDou realization of UTC. The timing pulse can also be configured to suit the user’s requirements.

Tallymatics TW5382 Smart GNSS antenna

The TW5382 supports an RS-485 communication interface, which enables the receiver to be configured and monitored.

Lastly, combining the GNSS antenna and receiver in a single package ensures that each smart antenna will produce precisely the same timing signal, as each smart antenna cable delay will be virtually identical. Only the user’s time pulse cable length (smart antenna to user equipment) will have to be considered, which simplifies the operator’s installation.

Both Tallysman and Tallymatics are owned by Calian, an Ottawa-based consulting firm.