Radio frequency transmitters

Part 1 book "Principles of electronic communication systems" includes content: Introduction to electronic communication; electronic fundamentals for communications; amplitude modulation fundamentals; amplitude modulator and demodulator circuits; fundamentals of frequency modulation; FM circuits; digital communication techniques; radio transmitters; communication receivers; multiplexing and demultiplexing; digital data transmission.

448p muasambanhan06 03-02-2024 3 1   Download

Part 1 book "Principles of electronic communication systems" includes content: Introduction to electronic communication; electronic fundamentals for communications; amplitude modulation fundamentals; amplitude modulator and demodulator circuits; fundamentals of frequency modulation; FM circuits; digital communication techniques; radio transmitters; communication receivers; multiplexing and demultiplexing.

388p muasambanhan06 03-02-2024 4 1   Download

Ebook "Electronics demystified" includes content: Direct current, alternating current, impedance and admittance, power supplies, emiconductor diodes, transistors and integrated circuits, signal amplifiers, signal oscillators, radio frequency transmitters, radio frequency receivers, telecommunications, communications antennas,... and other contents.

417p haojiubujain07 20-09-2023 6 3   Download

This paper investigates a cognitive radio network where a secondary sender assists a primary transmitter in relaying primary information to a primary receiver and also transmits its own information to a secondary recipient. This sender is capable of jamming to protect secondary and/or primary information against an eavesdropper and self-powering by harvesting radio frequency energy of primary signals. Security capability of both secondary and primary networks are analyzed in terms of secrecy outage probability.

27p nguathienthan9 08-12-2020 6 1   Download

Sometimes history seems to repeat. Even in the so-called ‘mature’ technological fields. When the radio pioneers such as Heinrich Hertz, Guglielmo Marconi, and Alexander Stepanovich Popov made their first experiments of wireless transmission more than a hundred years ago using spark-gap transmitters with simple coherer-detectors they did not care which ‘frequency band’ they were using, nor did they worry about their signals being ‘spectrally efficient’ or ‘band limited’. The world of radio frequency regulation was very simple then since regulations have not yet existed.

0p lyly_5 22-03-2013 77 3   Download

Radio based communication, open air The attacker, having a radio transmitter and receiver with the same radio frequency of the underlying wireless network, can easily: Intercept wireless data Connect his computing devices to a nearby wireless network Inject new packets to an existing wireless network Jam a particular wireless channel using a jamming device Security measures Implement encryption algorithms, authentication algorithms, and integrity-check algorithms at the data-link layer Provide network access with wired equivalent privacy Higher-layer protocols and applications can be used ...

32p muathu_102 28-01-2013 52 4   Download

A valve amplifier or tube amplifier is a type of electronic amplifier that makes use of vacuum tubes to increase the amplitude of a signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers during the 1960s and 1970s. Valve amplifiers are used for applications such as guitar amplifiers, satellite transponders such as DirecTV and GPS, audiophile stereo amplifiers, military applications (such as radar) and very high power radio and UHF television transmitters....

83p inguyentri 27-05-2011 125 31   Download

Propagation over Irregular Terrain Land mobile radio systems are used in a wide variety of scenarios. At one extreme, county police and other emergency services operate over fairly large areas using frequencies in the lower part of the VHF band. The service area may be large enough to require several transmitters, operating in a quasi-synchronous mode, and is likely to include rural, suburban and urban areas.

39p tienvovan 16-09-2010 66 5   Download

Fundamentals of VHF and UHF Propagation Having established the suitability of the VHF and UHF bands for mobile communications and the need to characterise the radio channel, we can now develop some fundamental relationships between the transmitted and received power, distance (range) and carrier frequency. We begin with a few relevant de®nitions. At frequencies below 1 GHz, antennas normally consist of a wire or wires of a suitable length coupled to the transmitter via a transmission line.

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FREQUENCY MODULATED RADIO TRANSMITTER In Chapter 2, the amplitude of a high-frequency (carrier) sinusoidal signal was varied in accordance with the waveform of an audio-frequency (modulating) signal to give an amplitude modulated (AM) wave which could be transmitted, received, and demodulated to recover the original audio frequency signal. In frequency modulated (FM) radio, the frequency of the carrier is varied about a fixed value in accordance with the amplitude of the audio frequency.

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Modern communication systems require radio frequency and microwave signals for the wireless transmission of information. These systems employ oscillators, mixers, ®lters, and ampli®ers to generate and process various kinds of signals. The transmitter communicates with the receiver via antennas placed on each side. Electrical noise associated with the systems and the channel affects the performance. A system designer needs to know about the channel characteristics and system noise in order to estimate the required power levels....

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Coherent Lightwave Systems The lightwave systems discussed so far are based on a simple digital modulation scheme in which an electrical bit stream modulates the intensity of an optical carrier inside the optical transmitter and the optical signal transmitted through the fiber link is incident directly on an optical receiver, which converts it to the original digital signal in the electrical domain. Such a scheme is referred to as intensity modulation with direct detection (IM/DD).

40p khinhkha 29-07-2010 80 6   Download