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A Mobile Satellite Communications (MSC) system is radio-relay station temporarily located at determined position in space (approximately between 20 and 36,000 km) to receive RF signals from different Mobile Earth Stations (MES), amplify the signals and transmit them back to Land Earth Stations (LES), which are connected to the ground telecommunication infrastructure. To provide those all functions in order satellite has to be equipped with adequate subsystems integrated by payload and bus. The payload is usually located inside of satellite body, which contains the transponder or transceiver system (satellite receivers and transmitters). The transponder is also connected to the receiving and transmitting antenna system, which are mounted outside on the satellite body. Therefore, each satellite must be stabilized in its orbital slot, which has to counteract the forces acting on the satellite motion and to keep the antennas of a satellite constantly pointing to a specific footprint of the Earth.

As one of the fundamental signal processing components in RF and microwave circuits, the filter plays a critical role in determining any system’s ultimate performance. Since the electromagnetic spectrum has become more and more densely populated, filter performance has taken on greater significance than ever because interference rejection is of paramount importance.

This Application Note describes chracterization of devices used in radar systems with pulsed signals. The emphasis is on measurements using vector network analyzers (VNAs), signal generators, vector signal generators and spectrum analyzers.

With marching orders to improve process uptime, drive down manufacturing costs and improve or maintain yield, while decreasing process-related defects, the semiconductor industry is turning to new materials that help meet their needs. The emerging solar technology industry is also using the materials to drive down their costs and increase their competitiveness in the marketplace

The N series of coaxial connector is the most widely used series for low to medium power applications in the DC to 11 GHz frequency range. The N connector is particularly well suited for applications in harsh environments or those where there is a high number of mating cycles. A relatively recent improvement has been the introduction of the Precision N connector, which operates up to 18 GHz. A major inconvenience of the traditional N connector is the threaded coupling mechanism. This has led to the invention of the Quick Lock N (QL-N) type connector, which showcases a quick disconnect feature.

At the SMA connector’s inception, the operating frequency didn’t exceed 12 GHz. As the design matured, the maximum operating frequency was pushed up to 18 GHz and eventually higher. As higher operating frequencies have become common over the past several decades, other interfaces, most of which are considered precision interfaces designed for laboratory use, have been introduced to handle signal transmission at frequencies far exceeding 18 GHz. However, the SMA connector design can be optimized to extend the maximum operating frequency of the interface to offer a reliable and cost-effective solution to the higher frequency requirements of modern systems.

This paper describes how LTE products, systems and applications are tested in a realistic wireless environment – not in the field but in a laboratory. The benefits of beyond conformance testing compared to standard conformance testing are explained. LTE terminal and base station manufacturers as well as operators are recommended to go beyond basic testing and carry out performance measurements already in the early phases of LTE product development. The White Paper also discusses the different testing methods and introduces key radio channel models which can be used in the testing process.

Averaging is a common technique for reducing the measurement uncertainty inherent in all measurements. Performing the same measurement a number of times and calculating the average of the measured values can often reduce the randomness of an experimental result. However, not all power averaging techniques give the same results. This paper dicusses the differences.

Prior to the circuit design and especially in larger designs, EM tools are used to create “library” parts such as inductors, transitions and antennas. While these parts are fairly self-contained, they must ultimately be integrated into the overall design where at the very least they must be connected to the rest of the circuit or in a more complex case be coupled to it. During both early and later stages of design, designers will switch from circuit-based models to EM analysis of critical interconnects to better understand couplings and achieve greater accuracy.

Until recently, all A-GPS testing to industry standards was performed using a cabled RF connection. As a consequence, devices that pass all tests in the existing conformance standards may perform poorly in the real world, resulting in an inferior enduser experience of LBS applications. This has led some industry leaders to put in place their own A-GPS OTA solutions.