Know-how ke stažení

K dispozici jsou vám i některá technická skripta z různých oblastí. 

Ta by Vám měla přinést pohled na základní pravidla, statistiky a podporovat Vás při práci. Možná je využijete pro oživení naučené látky či při přípravě na přednášku. I zkušení inženýři se při určitých dotazech dostanou do problem.

 

  • Amplifier

    Quality Measurements on Digital and Analog TV Transmitters Using the R&S®ETL

    All types of information transmission, including the „one-way“ transmission used in broadcasting, involve feeding a radio frequency (RF) signal to an antenna. This is the essence of the most basic type of transmitter used to emit electromagnetic waves. In the real world, however, a transmitter used for broadcast applications, for example, is much more complex in terms of its functions and design. The different transmitter components must be carefully coordinated. There are many quality parameters that are critical in ensuring that a proper output signal is delivered.

    Rohde & Schwarz designed the R&S ®ETL TV analyzer especially for broadcasting applications. The analyzer allows the measurement of the quality parameters that are relevant in analog and digital broadcasting. This Application Note describes the typical quality measurements performed during compliance testing of TV transmitters. The approach discussed here is based on the example of Rohde & Schwarz terrestrial transmitters for analog TV and DVB-T/H.

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  • Bluetooth

    This application note contains a short overview of the most important parameters and characteristics of Bluetooth®. It also describes new developments such as Enhanced Data Rate (Version 2.0 + EDR).

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  • dB or not dB

    30 dBm + 30 dBm = 60 dBm – correct or incorrect? Why is 1% sometimes -40 dB, and then 0.1 dB or 0.05 dB? Even experienced engineers are sometimes confounded by problems like this one. Regardless of whether we are dealing with power, voltage, reflection factors, noise factors, field strength or the like, the term dB is always used. What does this mean and how do we calculate with it? This application note will help you to recall information learnt in the past.

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  • The crest factor in DVB-T (OFDM) transmitters

    and its effects on defining the size of power components

    Power peaks of 20 dB over the effective value – are these at all possible? Absolutely. Indeed, since the introduction of digital transmission technology, these ranges are to be expected. To ensure that nothing “goes boom,” HF power components need to be sized according to the expected power peaks. If the crest factor (which can only be statistically calculated), i.e. the ratio of peak value to effective value, can be determined to a sufficiently precise degree, then this solves the problem of sizing the power components. These application notes serve to help the determination process by providing basic formulas, some relevant statistics and a practical perspective on the limiting factors within real transmitters.

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  • Field Strength and Power Estimator

    Determining the field strength from transmitted power is not an easy job. Various, quite complicated formulas have to be evaluated correctly. This application note explains how to calculate electric and magnetic field strength, and power flux density.

    A program associated with this application note helps with the calculation and converts Watts to mW and dBm, V/m to µV/m and dBµV/m as well as A/m to µA/m and dBµA/m. Additional applications are calculation of propagation loss or antenna factor e.g.

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  • HSUPA

    High Speed Uplink Packet Access

    High Speed Uplink Packet Access (HSUPA) is a 3GPP release 6 feature for WCDMA. Objective is to achieve uplink data rates of up to 5.76 Mbps and increase throughput and capacity. This application note introduces HSUPA concepts and explains key features.

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  • Introduction to MIMO Systems

    The demand for higher network capacity and for higher performance of wireless networks is not breakable. MIMO Systems are able to improve the spectral efficiency significantly, and consequently MIMO will play a key role in many future wireless communication systems. This application note gives an overview of the principles of MIMO Systems and the standardization of these.

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  • UMTS Long Term Evolution (LTE) Technology Introduction

    Even with the introduction of HSDPA and HSUPA, evolution of UMTS has not reached its end. To ensure the competitiveness of UMTS for the next 10 years and beyond, UMTS Long Term Evolution (LTE) is being specified in 3GPP release 8. LTE, which is also known as Evolved UTRA and Evolved UTRAN, provides new physical layer concepts and protocol architecture for UMTS. This application note introduces LTE technology and testing aspects.

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