-
Feeding antennas with proper signals can be difficult. The signal is often described as a voltage, and voltages are not well defined in electromagnetic wave formulations. There are several tricks to model voltage generators in such situations, and one is the magnetic frill. This model shows the basic steps of defining a magnetic frill voltage generator for a dipole antenna, and it also compares the resulting antenna impedance with known results.
標(biāo)簽：
difficult
described
antennas
Feeding
上傳時(shí)間：
2013-12-21
上傳用戶：GavinNeko
-
Main program running when workpiece is ready on deferent belt(deferent_ready=ture).
* Call Square_Wave subroutine to generate 0.5ms square wave on P1.2 to drive
* electromotor,then drive deferent belt step forward. When it steps to the measure
* zone, it stops to be measured. Then call A_D subroutine to transform analog
* signals to digital signals , after then call serial subroutine to transfer
* digital signals to PC. Call square wave subroutine to drive deferent belt step to
* original position waitting for defere ready flag to run the next circle.
標(biāo)簽：
deferent_ready
workpiece
deferent
program
上傳時(shí)間：
2017-08-31
上傳用戶：baiom
-
關(guān)于太赫茲微波窗的設(shè)計(jì)，寬帶傳輸，220GHz頻率左右。
標(biāo)簽：
微波窗
上傳時(shí)間：
2016-01-04
上傳用戶：winner79
-
In this paper, we consider the channel estimation
problem in Millimeter wave (mmWave) wireless systems with
large antenna arrays. By exploiting the inherent sparse nature of
the mmWave channel, we develop a novel rate-adaptive channel
estimation (RACE) algorithm, which can adaptively adjust the
number of required channel measurements based on an expected
probability of estimation error (PEE).
標(biāo)簽：
Estimation
Millimeter
Adaptive
Approach
Channel
Systems
Rate
MIMO
Wave
for
上傳時(shí)間：
2020-05-26
上傳用戶：shancjb
-
The telecommunications industry is undoubtedly in a period of radical change with
the advent of mobile broadband radio access and the rapid convergence of Internet
and mobile services. Some of these changes have been enabled by a fundamental
shift in the underlying technologies; mobile networks are now increasingly based
on a pure Internet Protocol (IP) network architecture. Since the first edition of this
book was published in 2009, a multitude of connected devices from eBook readers
to smartphones and even Machine-to-Machine (M2M) technologies have all started
to benefit from mobile broadband. The sea change over the last few years is only the
beginning of a wave of new services that will fundamentally change our economy, our
society, and even our environment. The evolution towards mobile broadband is one of
the core underlying parts of this revolution and is the focus of this book.
標(biāo)簽：
Networks
Packet
EPC
and
4G
上傳時(shí)間：
2020-05-27
上傳用戶：shancjb
-
The objective of this book is to allow the reader to predict the received
signal power produced by a particular radio transmitter. The first two
chapters examine propagation in free space for point-to-point and
point-to-area transmission, respectively. This is combined with a dis-
cussion regarding the characteristics of antennas for various purposes. In
chapter 3, the effect of obstacles, whether buildings or mountains, is
discussed and analytical methods, whereby the strength of a signal is the
shadow of an obstacle can be predicted, are presented.
標(biāo)簽：
Propagation
Essentials
Radio
Wave
of
上傳時(shí)間：
2020-05-27
上傳用戶：shancjb
-
In the nineteenth century, scientists, mathematician, engineers and innovators started
investigating electromagnetism. The theory that underpins wireless communications was
formed by Maxwell. Early demonstrations took place by Hertz, Tesla and others. Marconi
demonstrated the first wireless transmission. Since then, the range of applications has
expanded at an immense rate, together with the underpinning technology. The rate of
development has been incredible and today the level of technical and commercial maturity
is very high. This success would not have been possible without understanding radio-
wave propagation. This knowledge enables us to design successful systems and networks,
together with waveforms, antennal and transceiver architectures. The radio channel is the
cornerstone to the operation of any wireless system.
標(biāo)簽：
LTE-Advanced
Generation
Next
and
上傳時(shí)間：
2020-05-27
上傳用戶：shancjb
-
One of the prerequisites for the development of telecommunication services is the
understanding of the propagation of the waves, either acoustic, electromagnetic,
radio or light waves, which are used for the transmission of information.
In this work, we shall limit ourselves to the study of radio waves: this term
apply to the electromagnetic waves used in radio communications. Their
frequency spectrum is very broad, and is divided into the following frequency
bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF
waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves
(300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub-
EHF waves (300-3000 GHz).
標(biāo)簽：
Propagation
Radio
Wave
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
The focus of this book is on developing computational algorithms for transmit wave-
form design in active sensing applications, such as radar, sonar, communications and
medical imaging. Waveforms are designed to achieve certain desired properties, which
are divided into three categories corresponding to the three main parts in the book,
namely good aperiodic correlations, good periodic correlations and beampattern match-
ing.
標(biāo)簽：
Waveform
Desig
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
Over many years, RF-MEMS have been a hot topic in research at the technology
and device level. In particular, various kinds of mechanical Si-MEMS resonators
and piezoelectric BAW (bulk acoustic wave) resonators have been developed. The
BAW technology has made its way to commercial products for passive RF filters,
in particular for duplexers in RF transceiver front ends for cellular communica-
tions. Beyond their use in filters, micromachined resonators can also be used in
conjunction with active devices in innovative circuits and architectures.
標(biāo)簽：
MEMS-based
Circuits
Systems
and
上傳時(shí)間：
2020-06-06
上傳用戶：shancjb
