GPS transmitter and receiver, GPS antenna over fiber

Description

Portable single GPS timing over Fiber

The Thor Fiber portable F-1GPS-TX/RX systems are available to support the remote placement of industrial GPS antennas. These kits are assembled and tuned to the unique requirements of each application. Thor GPS over fiber systems are an excellent solution for distance limitations between maritime or government GPS antennas and radio signal receiver equipment. Typically, any sensor equipment or tuning hardware, such as universal time receivers or GPS navigation gear, must be installed and located within 100 ft of the antenna system. Most modern industrial type systems require antennas with a clear view of the horizon to function properly. In the case of large ocean-going vessels, underground military installations, or large buildings or structures (metropolis), it can be a challenge to install GPS equipment within 100 ft of a suitable antenna location. Thor solves this problem by extending the distance to over 20km by converting the GPS signal from the antenna's coax to fiber optic cable. F-GPS systems are available in a variety of form factors, and can be custom tuned to individual users' applications.

GPS reference timing signals are widely used to synchronize cellular base stations.

GPS systems typically consist of an active rooftop antenna, a GPS receiver, and a length of coaxial cable to connect them. Common challenges arise when the distance between the rooftop antenna and the cellular base station equipment (usually in the basement) is greater than 300 ft. Coaxial cable runs over 300 ft are not practical for most GPS receiver systems, so a fiber optic link is required at such distances, and Thor fiber optic links are some of the most trusted and cost-effective links in the industry.

Tags: GPS over fiber

Features

Supports all GPS frequencies internationally
Supports L1 at 1575.42 MHz, L2 at 1227.60 MHz, L3 at 1381.05 MHz, L4 at 1379.913 MHz, and L5 at 1176.45 MHz, L6 at 1278.75 MHz, and L7 at 1267.6 MHz GPS bands
Extends the range between GPS antennas and equipment to over 20 miles
Fiber links are immune to RF interference problems associated with coax
Ideal for broadcasting towers, cell sites, military installations, and large ships
Provides a fiber security break and insulates from lightning strikes
1 GPS input
1 independent fiber optic output SC/APC
N Female type RF connector
Portable power supply
Supports a high level of optical split and RF split for flexible routing of GPS for small cells and extended base station sites
Simple to install - no adjustment
Minimal signal loss and degradation over very long cable runs up to 20km.
Provides a highly secure, tamper-proof GPS over fiber connection between antenna and receiver.
Interference-free link through noisy environments; the optical signal is unaffected by electrical noise.
Electrical isolation between antenna and receiver protects against lightning strikes and electrical surge
Selectable GPS antenna powering voltage
Supports all L2 & L1& L5 GPS bands
The transmitter receiver kit comes with 110-220V AC to DC power supply

GPS base stations with long antenna cable runs
Run the GPS carrier to multiple GPS timing boards throughout a company
Run GPS throughout an aircraft
Satisfies the requirement of supplying multiple GPS receivers with a carrier, spread over a great distance
For R&D facilities, supplies a GPS carrier to a multitude of engineers and technicians with only one antenna on the roof.
DAS, WiMax, Satcom, LTE over fiber

IMPORTANT NOTE*** (It is very important to interface our unit with SC/APC - Angle Polished Connector to avoid any light reflections.)

If your fiber is terminated with the SC, ST, FC /PC flat connector, you need to use an optical jumper from PC type to SC/APC for proper conversion.

The L signals are different frequency bands used by GPS (Global Positioning System) satellites to transmit signals to GPS receivers. These frequencies are part of the evolution of GPS technology, providing higher accuracy, better reliability, and more advanced features, especially with the modernization of GPS.

Here are the key L bands for GPS and their corresponding frequencies:

1. L1

Frequency: 1575.42 MHz
Description: The L1 frequency is the most commonly used frequency for civilian GPS receivers. It carries the C/A (Coarse/Acquisition) code and the P(Y) code (for military use).

2. L2

Frequency: 1227.60 MHz
Description: L2 is mainly used for military applications but can also be used for civilian applications, particularly in high-accuracy GNSS systems with dual-frequency receivers. It carries the P(Y) code and the L2C code for civilian use.

3. L3

Frequency: 1381.05 MHz
Description: L3 is used primarily for nuclear detonation detection and is not used for standard GPS navigation.

4. L4

Frequency: 1379.913 MHz
Description: L4 is used primarily for ionospheric calibration and research purposes. It is part of the GPS III modernization but has not yet been widely used for navigation.

5. L5

Frequency: 1176.45 MHz
Description: L5 is a high-precision, safety-of-life signal for both civilian and professional applications. It offers improved accuracy and is used for critical applications such as aviation. L5 is a new signal available from GPS III satellites.

6. L6

Frequency: 1278.75 MHz
Description: L6 is used primarily for commercial purposes and is part of the GPS III modernization. This signal is intended for high-accuracy applications and is used by the GPS III satellites to provide improved performance.

7. L7

Frequency: 1267.6 MHz
Description: L7 is part of the GPS III modernization program and is intended for both military and civilian use, contributing to a more robust and accurate GPS system.

Summary of GPS L Bands and Corresponding Frequencies:

Signal	Frequency (MHz)	Description
L1	1575.42	Civilian (C/A code), Military (P(Y) code)
L2	1227.60	Military (P(Y) code), Civilian (L2C code)
L3	1381.05	Nuclear Detonation Detection (Not used for navigation)
L4	1379.913	Ionospheric Research (Limited Use)
L5	1176.45	Civilian Safety-of-Life (Aviation)
L6	1278.75	Commercial Use (GPS III)
L7	1267.6	Modernized GPS III Signal

These frequencies ensure that GPS signals can be used effectively in various applications, from consumer navigation to precise scientific and military purposes. The modernized signals like L5, L6, and L7 are designed to offer enhanced performance in terms of accuracy, reliability, and resistance to interference.

Drawings

Model Selection

F-1GPS-TX/RX - 1GPS over fiber Transmitter/Receiver kit (both ends) - 1mW laser (20km distance)

F-1GPS-TX - 1GPS over fiber Transmitter only - 1mW laser - 0dBm optical output power (20km distance)

F-1GPS-RX - 1GPS over fiber Receiver only

F-1GPS-TX-10mW - 1GPS over fiber Transmitter only - 10mW laser +10dBm optical output power

Specification

All Specifications Subject to Change Without Notice IMPORTANT NOTE (It is very important to interface our unit with SC/APC - Angle Polished Connector to avoid any light reflections.) If your fiber is terminated with the SC, ST, FC /PC flat connector, you need to use an optical jumper from PC type to SC/APC for proper conversion.
Electro Optical Characteristics
Optical Output Optical Output Power Receiver Sensitivity Optical budget	1 mW min. (F-1GPS-TX - 1GPS over fiber Transmitter only - 1mW laser - 0dBm optical output power (20km distance) (0-+3)dBm -10dBm 10 dB (* F-1GPS-TX-10mW** - 1GPS over fiber Transmitter only - 10mW laser +10dBm optical output power)
Wavelength	1310 nm (1550 nm or CWDM special order only)
RF Characteristics
Frequency Range	1100 - 1585.42 MHz
CNR	60 dB
Input VSWR (50 Ohm)	2.0:1 max
MW/ma@1200Mhz	0.1 mW/ma min
1dB Compression	-25 dBm
Power Power to the Antenna	12VDC, 1.5A AC to DC power supply - Included (F-Type Female) 5V DV (ON/OFF switch)
Physical Characteristics
Dimensions	Height 1 1/16" Width: 4 1/32" (with RF and Fiber connectors) Length: 4"
Link Characteristics
Link Loss	15 dB typical
Carrier/Noise (30khz BW)	15 dB min with input drive level at 70 dBm
3rd Order Intercept	22 dBm
Environmental Conditions
Operating Temperature	-25 to +70 (deg C)
Storage Temperature	-30 to +75 (deg C)
Mechanical
Optical Connectors Electrical Connector	SC/APC Fiber S/M 9/125 N type Female

Question and Answers

Question:
It looks like the fiber used is Singlemode, but I need to confirm this?

Answer:
Yes, our GPS over Fiber units all use Singlemode fiber; they do not work on Multimode. We have multiple options for the GPS units, as well as a multi-channel unit with up to 4 GPS inputs. All of these units will only work on Singlemode fiber.

Question:
I want to confirm whether this will work with a Trimble Thunderbolt E GPS Disciplined Clock Starter Kit (62989-50).

Answer:

There is no reason why it shouldn't; our units are wideband and totally transparent.

Question:
What are the GPS frequencies, and how do you send GPS signals over fiber?

Answer:

GPS (Global Positioning System) is a satellite-based navigation system that allows users to determine their precise location, speed, and time anywhere on Earth. GPS signals are transmitted from a network of satellites orbiting the Earth and can be received by GPS receivers on the ground or in aircraft, ships, and other vehicles.

GPS frequencies are within the L-band range of the radio frequency spectrum, specifically within the 1575.42 MHz frequency band. These signals are very weak, with an average power of just -160 dBm (decibel-milliwatts), and are susceptible to interference and signal loss over long distances.

To send GPS signals over fiber optic cables, a GPS modulator and a fiber optic transmitter are used. The GPS modulator converts the GPS signals into a format that can be transmitted over fiber optic cables, while the fiber optic transmitter sends the signals over the fiber optic cables to the desired location.

There are several types of fiber optic transmitters that can be used to send GPS signals over fiber, including both analog and digital transmitters. The choice of transmitter will depend on the specific requirements of the application, including the distance the signal needs to be transmitted, the type of fiber optic cable being used, and the data rate of the signal.

It is also important to note that GPS signals are susceptible to interference and signal loss over long distances, so it may be necessary to use amplifiers or repeaters to boost the signal along the way. This is particularly important when transmitting GPS signals over long distances, as the signals can become degraded due to factors such as atmospheric conditions and other sources of interference.

In addition to being used for navigation and location-based services, GPS signals are also used in a wide range of applications, including surveying, mapping, timing, and scientific research. The ability to transmit GPS signals over fiber optic cables enables a wide range of possibilities for these applications, including the ability to transmit GPS signals to remote locations that may not be accessible by other means.

Fiber optic cables are a reliable and efficient means of transmitting GPS signals over long distances. They offer several advantages over traditional copper cables, including higher bandwidth, higher data rates, and immunity to electromagnetic interference. They are also more resistant to physical damage and are less susceptible to corrosion.

To transmit GPS signals over fiber optic cables, the signals must be converted into a format that is compatible with fiber optic transmission. This is typically done using a GPS modulator, which converts the GPS signals into an optical format that can be transmitted over fiber optic cables.

There are several types of GPS modulators available, including both analog and digital modulators. Analog modulators use continuous wave (CW) lasers to transmit the GPS signals, while digital modulators use pulse-code modulation (PCM) to transmit the signals in digital form. The choice of modulator will depend on the specific requirements of the application, including the distance the signal needs to be transmitted and the data rate of the signal.

Once the GPS signals have been modulated, they can be transmitted over fiber optic cables using a fiber optic transmitter. There are several types of fiber optic transmitters available, including both analog and digital transmitters. The choice of transmitter will depend on the specific requirements of the application, including the distance the signal needs to be transmitted, the type of fiber optic cable being used, and the data rate of the signal.

It is also important to note that GPS signals are susceptible to interference and signal loss over long distances, so it may be necessary to use amplifiers or repeaters to boost the signal along the way. This is particularly important when transmitting GPS signals over long distances, as the signals can become degraded due to factors such as

Question:
Attached is the GPS antenna that will be utilized in our system. This GPS antenna is what we will need your equipment to interface with. This drawing is crude, but this is how we plan to use it: Overall Diagram Figure 4: Overall Example Usage I am also attaching the GPS antenna that we are using. Will this work for what we are attempting to do? INNOVATIVE DESIGN WITH MULTIPLE PATENTS The VEXXIS GNSS-800 series antennas feature a patented multi-point feeding network and radiation pattern optimization technology. In addition to having enhanced performance in multipath environments, the GNSS-850 antenna is able to maintain a low profile while achieving both high peak zenith gain and low gain roll-off from zenith to horizon, without sacrificing tracking performance. This new technology significantly enhances low-elevation-angle tracking capabilities, extending operation to the entire GNSS constellation. Furthermore, the antenna is able to achieve greater phase center stability through our innovative element design. This directly translates into improved carrier phase measurement and a better RTK solution. TRACKING IN CHALLENGING ENVIRONMENTS The ability to track low-elevation satellites while maintaining a high gain for higher elevation satellites makes the GNSS-850 an excellent choice for any applications where the sky is partially visible, such as operating close to tree lines, under foliage, or in urban canyons. The antenna is able to track any visible satellites from horizon to zenith, providing the maximum number of observations for an enhanced positioning solution. NOVATEL'S TOUGHEST PRECISION ANTENNA GNSS-800 antennas are the toughest high-precision antennas NovAtel has designed to date, ensuring their survivability even in the harshest operating environments. The antennas feature ultra-durable watertight enclosures and have been proven to sustain intense vibration, earning the MIL-STD-810G rating. PERFORMANCE Signal Received GPS L1, L2, L5 GLONASS L1, L2, L3 Galileo E1, E5a/b, E6 BeiDou B1, B2, B3 L-Band Pass Band (typical) Upper passband 1569.0 +/- 43.0 MHz Lower passband 1232.0 +/- 68.0 MHz Out-of-Band Rejection Band edges +/- 50 MHz 40 dB minimum Band edges +/- 100 MHz 60 dB minimum LNA Gain 29 dB (typical) Gain at Zenith (90 deg )1 L1/B1/E1/G1 +5.0 dBic minimum L2/B2/E5b/G2 +5.0 dBic minimum L5/E5a +3.0 dBic minimum L-Band +5.0 dBic minimum Gain Roll-Off (from Zenith to Horizon) L1/B1/E1/G1 10 dB L2/B2/E5b/G2 12 dB L5/E5a 12 dB L-Band 10 dB Phase Center Stability

Answer:
If your signal is GPS, please consider F-GPS-TX/RX, not the L-Band TX/RX. GPS operates at a very low RF level and requires a 50-ohm termination.

Based on the antenna specifications, it looks like it should work because we are directly modulating incoming RF signals into an optical wavelength output. It should be quick and easy to set up. Just make sure you have single-mode fiber and SC/APC connectors.

Question:
We need to install a Cobham Explorer 710 BGAN satellite terminal in an overseas mission with more than 500 feet between the antenna and the transceiver. We will need to use a single-mode fiber to achieve this distance compared with the LMR400 - 50 Ohms Coax. We need coax-to-fiber media converters capable of supporting both transmission and reception in L-Band frequencies. I have attached a diagram with our potential layout. The devices in the yellow field below are just a representation of our fiber media requirements that we seek from vendors.

Answer:
Thanks for calling. This is a very straightforward, simple solution: our part number F-LBand-TxRx The kit comes with a transmitter, receiver, and power supplies. https://thorbroadcast.com/product/l-band-over-fiber-tx-rx-basic-1-ch-kit.html

Question:
I am looking at the GPS-TX model, and it says that it supports L1 and L2 frequency bands and that it transmits all common bands (GPS, GALILEO, and GLONASS). Do you know if this also includes transmitting L5 for F-GPS-TX-WE or F-GPS-TX/RX?

Answer:

Note on Equipment Supporting All GPS L Bands

Our GPS equipment is designed to support a wide range of GPS signals, ensuring maximum performance, accuracy, and flexibility across different applications. The equipment is compatible with the latest modernized GPS signals, enabling enhanced precision, robustness, and reliability for both civilian and military use. Below is a list of the GPS L bands and their corresponding frequencies that our equipment supports:

Supported GPS L Bands and Frequencies:

L1 - 1575.42 MHz Civilian (C/A code), Military (P(Y) code)
L2 - 1227.60 MHz Military (P(Y) code), Civilian (L2C code)
L3 - 1381.05 MHz Nuclear Detonation Detection (not used for navigation)
L4 - 1379.913 MHz Ionospheric Research (limited use)
L5 - 1176.45 MHz Civilian Safety-of-Life (Aviation)
L6 - 1278.75 MHz Commercial Use (GPS III)
L7 - 1267.6 MHz Modernized GPS III Signal

Question:
Thanks for the quick response. We wouldn't need anything bidirectional - just need to repeat the GPS signal from outside into the building. Should match close to the diagram below. These cell boosters have a silly requirement to have a GPS antenna attached, which, in my opinion, defeats the purpose of installing them deep inside buildings where cell signals don't penetrate. That's where I believe your product might come in handy. The fiber optic coupler shown below (F-PLC-1x4) is a passive device, correct? How many can we use before the signal gets attenuated too much? Is the GPS OUT port intended to go directly into the GPS input of another device or an antenna?

Answer:

Yes, the fiber optic coupler shown (F-PLC-1x4) is a passive device.

Our standard 1 mW TX can be split up to 4 times. We also offer a 10 mW TX that can be split up to 16 times, depending on your setup.

Regarding your question about the GPS OUT port: yes, the RF output has unity gain relative to the RF input from the antenna. It is intended to connect directly to the GPS input of your equipment (not to another antenna).

How many endpoints are you looking to support? If you require multiple endpoints, there are two recommended configurations:

Multiple 1 mW TX units with individual 1x4 splitters - This setup provides redundancy and flexibility.
A single 10 mW TX with a 1x16 optical splitter - This is more centralized and efficient for higher endpoint counts.

Question:
I need to replace a coax run in my building with fiber for LTE cellular frequencies. I was looking at your L-band over fiber Tx+Rx Basic 1 channel kit. The fiber run would be short, probably a max of 600 ft. We purchased the transmitter and receiver listed below to install a weBoost Office 100 cell signal booster. Our goal was to extend the distance between the outdoor antenna and the indoor antenna using the equipment we purchased from you; however, this setup did not work as expected. I spoke with someone last week regarding this issue, and they advised me to send an email with detailed information so that you could review our setup and recommend suitable products. Please let me know if you have any other products that would work for this type of configuration, or if you have any recommendations to achieve the desired distance extension. Thank you for your assistance.

Answer:

Here is the link to the 75Ohm L-Band over Fiber TX/RX kit: https://thorbroadcast.com/product/l-band-over-fiber-tx-rx-basic-1-ch-kit.html

Here is the link to the 50Ohm GPS over Fiber TX/RX kit (both can cover cellular frequencies): https://thorbroadcast.com/product/1-gps-fiber-transport-system.html

However, these are unidirectional transmitter/receiver sets. For cellular applications, you would typically need two sets, along with an RF circulator or (even better) a diplexer.

Hopefully that makes sense - we have had clients use this solution for Cellular over Fiber, and it works great as long as your RF spectrum stays within the supported frequency range.

Here is the connection diagram: