A new line-of-sight (LoS) kit consisting of the Spectrum Compact handheld microwave spectrum analyzer, an SG Compact signal generator and two portable beacon antennas is claimed to be the first dedicated microwave link LoS verification kit. It is designed to make sure there are no obstacles or interference disrupting the microwave hop. The main purpose of the kit is to make long distance link installation faster, more reliable and less expensive. It is aimed at installers, system integrators and network owners, as well as mobile operators.
Typically, installers have to physically survey the whole distance of the longest links to make sure there are no obstacles within the planned path. It can be a time-consuming and expensive process that can’t guarantee that the link is effectively deployable within the chosen path. With the LoS kit, it is possible to verify distances up to 85 km with high accuracy. Additionally, the kit enables the lowest possible antenna height on the tower to be ascertained, decreasing the total cost of link ownership. Also, if a newly installed link isn’t operating, it is difficult for installers to discover whether it is due to technical issues or obstacles in the chosen path. SAF’s LoS verification kit eliminates the possibility of the latter.
Figure 1 The Spectrum Compact is no larger than a cell phone and weighs only 10.6 oz.
The process of LoS verification requires a 6 GHz SG Compact signal generator that transmits the signal to the far side of the proposed link at up to 13 dBm output power. The Spectrum Compact spectrum analyzer (shown in Figure 1) serves as the receiver and has -105 dBm/MHz sensitivity. The two wide-angle beamwidth beacon antennas included in the kit have 22 dBi amplification for easier long distance link verification.
SG Compact Signal Generator
The SG Compact signal generator is a tool for antenna alignment, testing and LoS verification. It has intuitive controls, an interactive GUI and instant on/off functionality. It has the same form factor as the Spectrum Compact (5.04" × 3.2" × 0.94") and weighs 10.6 oz. Currently there are three devices covering frequencies from 6 to 40 GHz.
It is an effective and easy solution when it’s not clear whether the planned radios will have LoS when installed. For verification, SG Compact sends a CW signal at the chosen frequency to a Spectrum Compact unit at the remote site (see Figure 2) and is able to verify line of sight with 100 percent accuracy.
For antenna alignment prior to radio installation, a SG Compact is attached to one of the installed antennas and a Spectrum Compact to the other to perform a quick and easy alignment. The SG Compact and Spectrum Compact can also verify that waveguides are not defective before installing the link, something that previously required expensive laboratory equipment. Also, by attaching the SG Compact to an antenna and placing a Spectrum Compact in close proximity (depending on the size of the antenna), the setup can measure the antenna gain.
Spectrum Compact Analyzer
The Spectrum Compact spectrum analyzer is an ultra light and easy-to-use measurement solution for the 2 to 40 GHz licensed microwave frequency bands. Designed specifically for comfortable outdoor use in a variety of challenging environments, this battery-powered device is specifically designed for microwave radio engineers performing equipment installation, link troubleshooting or gathering data for site planning. One of its most prominent features is its form factor –the dimensions of the device don’t exceed those of a cell phone, and it weighs only 10.6 oz.
Figure 2 To verify the LoS for a long-distance link, simply attach the antenna to the SG Compact signal generator and point it towards the Spectrum Compact spectrum analyzer on the far side of the link.
Instead of focusing on features that would only be useful in a laboratory environment, this device has the qualities and functionality needed by microwave field engineers to efficiently perform their daily tasks: radio parameter verification, antenna alignment, interference and multipath detection, in-band power measurements, link troubleshooting and saving the spectrum curves for reports and later analysis.
Spectrum Compact utilizes a resistive touch screen for ease of use in the field, allowing engineers to wear gloves when using the device. Furthermore, its high sensitivity (-105 dBm/MHz) and low noise floor enable field engineers to detect even exceptionally weak signals. It facilitates the performance of a multitude of tasks from the ground level and enables link troubleshooting without site traffic interruptions.
A standard kit includes the spectrum analyzer, RF cable and a waveguide adapter. The waveguide adapter can be used as a low gain antenna – the Spectrum Compact will detect and visualize the incoming signal just by pointing it towards the transmitting radio. SAF also provides a set of handheld horn antennas for use with Spectrum Compact as an additional accessory to detect interference when a parabolic antenna is not onsite. It is compatible with any manufacturer’s antenna.
SAF Tehnika
Riga, Latvia
www.saftehnika.com