White Papers

Wireless and Stimulus: A Perfect Match

When it comes to securing broadband stimulus funds, network providers are currently faced with some fairly uncertain circumstances. Challenged with navigating through the uncertain fund allocation process, operators continue to struggle with determining how to write a convincing and winning application and choosing the right solution, technology and vendor to best suit their specific needs.
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Generating X-parameters from Circuit-level Designs

X-parameters represent a new category of nonlinear network parameters for high-frequency design and are used for characterizing the amplitudes and relative phase of harmonics generated by the nonlinear behavior of components. Developed and introduced by Agilent Technologies, X-parameters are applicable to both large-signal and small-signal conditions, and for linear and nonlinear components. They correctly characterize impedance mismatches and frequency mixing behavior to allow accurate simulation of cascaded nonlinear X-parameter blocks (e.g., amplifiers and mixers), in wireless design. X-parameters play a key role in the development of active devices like the power amplifier (PA) and mixers—critical components in today’s wireless designs.
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Understanding Long-Term Evolution Fundamentals and Measurement Challenges

The Universal Mobile Telecommunication System (UMTS), the successor to GSM, is steadily increasing its penetration of the world’s wireless communications markets, and is likely over time to become the primary standard used by not just the current 85% wireless carriers, but by virtually all of them. Its most promising emerging enhancement, Long-Term Evolution (LTE), has moved further along in the standards-setting process and on to the path of initial deployment.
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A Comparison Between Thin Film and Thick Film Capacitors

Capacitor technology is constantly evolving and advancing to meet design engineers’ requirements as they develop the latest electronic designs. Whether a new design or redesign is driven by size or performance requirements (or both), design engineers are in need of advanced components that enable them to produce smaller, faster, higher performance designs.
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Satellite DVB-RCS Standards for Fixed and Mobile Commercial and Military Applications

The first generation of satellite standard of DVB-S known as Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) about ten years ago quickly became around the globe one of the key solutions in almost every new satellite communication project for broadcast, broadband and multimedia interactive applications including high-speed Internet. The second generation of DVB-S2 CCM (Constant Coding Modulation) standard was presented a few years ago as a new more cost effective, efficient, reliable, secure and functional solution. The DVB-S2 CCM can be upgraded and cost less than the third generation of DVB-S2 ACM (Adaptive Coded Modulation) platform, forward and reverse compatible. In this article will be introduced the latest DVB-S2 Space and Ground segments, respectively, for interactive transmission of Voice, Data and Video (VDV) over IP (VDVoIP). The Ground Segment will be represented by HUB as GES (Ground Earth Station) and VSAT equipment known Satellite Interactive Terminal (SIT) or Remotes, compliant to all DVB-RCS standards for civilian and military solutions.
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Airborne Satellite Antenna Mount and Tracking Systems

The communication Mobile Satellite Antenna (MSA) for transport applications are relatively large and heavy, especially the airborne High Gain Antenna (HGA) system for Inmarsat-H and High Speed Data (HSD) Aircraft Earth Stations (AES). Thus, over the past decade the steering airborne antenna system, which comprises the mechanical assembly, the control electronic system, the microwave electronic package and the antenna assembly (arrays and steering elements), has been reduced considerably in both physical size and weight. These reductions brought about by greater Effective Isotropic Radiated Power (EIRP) from satellite transponders coupled with GaAs-FET technology at the front end the receiver leading to higher G/N RF amplifiers, have made initially the fitting of shipborne antennas on tracks, locomotives and airplanes a reality. A little later airborne and vehicle borne MSA were developed on the basis of these shipborne antennas. The MSA systems are always required to be pointed towards the satellite in spite of mobile motions. Namely, the mount system is one of the main requirements in designing the MSA systems from the technical and rational viewpoints. The several types of mount system are used: such as mechanical, electrical and other, especially those concerned with shipborne MSA. Whereas, in the case of airborne and vehicleborne MSA, electrical pointing systems are preferable.
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Extending 2.4 GHz ZigBee Short Range Radio Performance

The SKY65336 and SKY65337 ZigBee front-end modules (FEMs) can greatly enhance the performance of a ZigBee radio solution when integrated with any ZigBee low power reference design. Both devices can transmit up to 100 times more power than a typical 0 dBm low power ZigBee radio transmitter and can reduce the level of unwanted spurious emissions to be compliant with the main regulatory standards without the use of external components such as filters. Ember’s EM250 with Skyworks’ FEM reference design [1] shows a good example of the complete subsystem.
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Spacecraft Payload for MSC Networks

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.
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How to Specify RF and Microwave Filters

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.
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