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what is difference between repeater and amplifier


In digital communication systems, a repeater is a device that receives a digital signal on an electromagnetic or optical transmission medium and regenerates the signal along the next leg of the medium. In electromagnetic media, repeaters overcome the attenuation caused by free-space electromagnetic-field divergence or cable loss. A series of repeaters make possible the extension of a signal over a distance.

Repeaters remove the unwanted noise in an incoming signal. Unlike an analog signal, the original digital signal, even if weak or distorted, can be clearly perceived and restored. With analog transmission, signals are restrengthened with amplifiers which unfortunately also amplify noise as well as information.

Because digital signals depend on the presence or absence of voltage, they tend to dissipate more quickly than analog signals and need more frequent repeating. Whereas analog signal amplifiers are spaced at 18,000 meter intervals, digital signal repeaters are typically placed at 2,000 to 6,000 meter intervals.

An amplifier is an electronic device that increases the voltage, current, or power of a signal. Amplifiers are used in wireless communications and broadcasting, and in audio equipment of all kinds. They can be categorized as either weak-signal amplifiers or power amplifiers.

Weak-signal amplifiers are used primarily in wireless receivers. They are also employed in acoustic pickups, audio tape players, and compact disc players. A weak-signal amplifier is designed to deal with exceedingly small input signals, in some cases measuring only a few nanovolts (units of 10-9 volt). Such amplifiers must generate minimal internal noise while increasing the signal voltage by a large factor. The most effective device for this application is the field-effect transistor. The specification that denotes the effectiveness of a weak-signal amplifier is sensitivity, defined as the number of microvolts (units of 10-6 volt) of signal input that produce a certain ratio of signal output to noise output (usually 10 to 1).

Re: what is difference between repeater and amplifier

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a repeater is an amplifier…amplifying the input signal out to the other side.

However, repeaters also amplify noise as well therefore limiting the number of repeaters used in any given network segment.

Intelligent repeaters and bridges will amplify signal, but without the noise…the signal being regenerated before sending.

repeater research papers

Implementation of a Software-Defined Radio based Global Positioning System Repeater
free download

Abstract Software-Defined Radios (SDR) are a step forward in the evolution of wireless
communications. Through well-established programming tools including, but not limited to,
VHSIC Hardware Description Language (VHDL), C++, MATLAB, and Python, an engineer

Rate analysis for a hybrid quantum repeater 12: 00–2: 00 Lunch
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The hybrid quantum repeater protocol is based on atomic qubit-entanglement distribution
through optical coherent-state communication [1]. We present an exact analytical formula for
the rates of entanglement generation in a hybrid quantum repeater assuming perfect

Reconfigurable Microwave Photonic Repeater for Broadband Telecom Missions: Concepts and technologies
free download

Thales Alenia Space has elaborated innovative telecom payload concepts taking benefit
from the capabilities of photonics and so-called microwave photonics. The latter consists in
transferring RF/microwave signals on optical carriers and performing processing in the

Supporting Odour Source Localisation of Multi-Sniffer Robots with up-Wind FormationRepeater Network Topology
free download

Abstract:Researchers have been working on odour tracking and sniffing robotics research,
the purpose of the research is to replace sniffer dogs in Odour Source Localisation (OSL)
task. Sniffer dogs have constraints in performing OSL task ie indentify the location of

Classification of Quantum Repeater Attacks
free download

Abstract:The main service provided by the coming Quantum Internet will be creating
entanglement between any two quantum nodes. We discuss and classify attacks on
quantum repeaters, which will serve roles similar to those of classical Internet routers. We

Fast Repeater Tree Construction
free download

We live in a world where computer chips can be found in nearly every device we come into
contact with. On the one hand, there is a huge demand for powerful but not power-
consuming chips that can be added to our wearables, houses or household items. On the

Improving HSDPA indoor coverage and throughput by repeater and dedicated indoor system
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target of the paper is to provide guidelines for indoor planning and optimization using
an outdoor-to-indoor repeater or a dedicated indoor system. The paper provides practical
information for enhancing the performance of high-speed downlink packet access (

Compact repeater antenna system with extremely high isolation in the 800 MHz band
free download

The radio repeater is an attractive solution for cost-effective expansion of coverage in
cellular systems. The direct relay radio repeater (not the frequency conversion type) is
particularly cost-effective due to its simple structure. However, when this type of repeater is

Repeater analyses for TOEFL iBT
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Abstract The operational administrations of TOEFL iBT began in September 2005 and
gradually expanded to the rest of the world in 2006. Some TOEFL iBT test-takers chose to
take the test more than once and they were categorized as repeaters. Knowledge about

Effects of inductance on the propagation delay and repeater insertion in VLSI circuits: A summary
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Abstract:The importance of on-chip inductance is continuously increasing with higher
operating frequencies and technology scaling trends. However, industry currently uses
primarily RC models to characterize the interconnect. This paper describes the effects of

Design of a Wideband Indoor Repeater Antenna With High Isolation for 3 G Systems
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Abstract:In this letter, a wideband antenna for 3G indoor re-peater applications is
proposed. A wide impedance bandwidth was achieved using a 3-dB attenuator and mutual
coupling between main and parasitic patches. The fabricated antenna has a VSWR below

Repeater patterns on NCLEX using CAT versus NCLEX using paper-and-pencil testing
free download

3 sufficiently above or below the pass/fail cutscore, the CAT terminates. Decision rules for
termination are based on comparing a confidence interval defined around the candidate’s
theta estimate with the theta level that defines the pass/fail cutscore. 1 As long as the

Implementation of Self Interference Cancellation for WCDMA Repeater
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Abstract. In this paper, the FPGA (Field Programmable Gate Array) implementation of self
interference cancellation technique based on an adaptive LMS (Least Mean Square)
algorithm is presented. By using the FPGA Virtex@ 6 HW module, the field data measured

Indoor positioning using time synchronized switching GPS repeater
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ABSTRACT Another new method for the GPS repeater based indoor positioning is proposed
and its feasibility is verified by experiments in previous paper. But the problems how can
identify switching GPS repeater’s ID and when switching will be occurred are remained.

CDMA2000 Network Repeater Deployment Experience
free download

A good off air deployment practice is to have repeater maintain maximum gain with minimal
isolation needs. The need for isolation is to prevent the unit from oscillating. Typically a 15
dB difference between Repeater gain and Port to Port (Donor/Server) path loss is needed

Repeater Basics/Refresher
free download

Copyright 2010 Jon Perelstein 1 Repeater Basics/Refresher Presented to the Stamford Amateur
Radio Association by 7 We use repeaters to get more range The repeater REPEATS your signal
so that it can go further Plus, most repeaters have their antennas mounted up high

Efficient interconnect design with novel repeater insertion for low power applications
free download

Abstract: Length of interconnect and number of repeaters are increasing with the
advancement in VLSI Technology. Requirement of repeaters is increasing as the length of
interconnect is increasing. The power delay product and frequency of operation plays

Improving HSDPA indoor performance using outdoor repeater
free download

Abstract This paper presents how HSDPA performance can be improved indoors by using
radio frequency repeaters. The radio signal is captured from outdoor macrocellular network
and guided to indoor distributed antenna system through an amplifying repeater.

Positioning-free resonant wireless power transmission sheet with staggered repeater coil array (srca)
free download

Abstract:A magnetically resonant wireless power transmission sheet (WPTS) on a printed
circuit board is developed. WPTS wirelessly supplies the power to electronic devices
including the wearable wireless healthcare devices anywhere on the sheet with high

An improved quantum repeater protocol using hyperentangled state purification
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Abstract This article indicates an improved protocol of quantum repeaters through the
scheme of nest entanglement purification [Phys. Rev. Lett. 81, 5932 (1998)]. The
hyperentangled photon pairs are utilized to overcome the limitations of long distance

Fuel cell/photovoltaic integrated power system for a remote telecommunications repeater
free download

The Schatz Energy Research Center built and operated a PEM fuel cell power system to
supply back-up power to a remote photovoltaic-powered radio-telephone repeater. The fuel
cell starts automatically when solar insolation is insufficient to maintain the state-ofcharge

Cellular/wireless LAN repeater system by wireless optical link with optical power supply
free download

Abstract:-Wireless market, such as cellular systems and wireless LAN, becomes huge and is
still expanding. Since operational frequency and transmission bit rate are increasing, much
more base stations or access points are necessary to overcome capacity and link budget

Exact dispensing of whole blood using the Eppendorf positive displacement system Multipette Xstream /Repeater Xstream
free download

Dispensing systems in the laboratory can function either by employing the air cushion
principle, or they constitute a positive displacement system [1]. In an air cushion pipette, an
air cushion separates the liquid in the plastic tip from the piston inside the pipette. Since

Local traffic prediction-based bandwidth allocation scheme in EPON with active forwarding remote repeater node
free download

Abstract We propose a novel local traffic predictionYbased bandwidth allocation mechanism
incorporated with remote repeater based EPON with active forwarding. This mechanism

A long-distance quantum repeater gets one step closer
free download

An example of a quantum memory is a stationary quantum system that can store information
encoded in a photon. Such a quantum memory would be an important tool in realizing a
quantum repeater a system that extends the range of a quantum link. A set of quantum


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