mạch điện lò vi sóng
Tài liệu RF và mạch lạc lò vi sóng P1 ppt
Ngày tải lên :
15/12/2013, 11:15
... the
appendices. Chapter 2 provides an overview of wireless communication systems and
their characteristics.
8
INTRODUCTION
TABLE 1.4 Selected Applications of Microwave Solid-State Devices
Devices Applications ... carry the video information as well. Table 1.1 shows the
frequency bands used for commercial radio and television broadcasts.
In the case of digital transmission, a standard monochrome television ... terrestrial
communication system.
Figures 1.3 and 1.4 list selected devices used at RF and microwave frequencies.
Solid-state devices as well as vacuum tubes are used as active elements in RF and
microwave...
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Tài liệu RF và mạch lạc lò vi sóng P2 pdf
Ngày tải lên :
15/12/2013, 11:15
... illustrated in Figure 2.7. A
microwave signal generated by the oscillator is split into two parts via the power
divider. The circulator feeds one part of this power to the antenna that illuminates a
target ... Doppler
frequency if the target is moving. Note that the signal travels twice over the same
distance and, therefore, the Doppler frequency shift in this case will be twice that
found via (2.4.33). Mathematically,
o
o
... on-board
electronics before transmitting it back. The gravitational force needs to be balanced
somehow if this object is to stay in position. An orbital motion provides this
balancing force. If a satellite...
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Tài liệu RF và mạch lạc lò vi sóng P3 docx
Ngày tải lên :
15/12/2013, 11:15
... converted to corresponding
impedance by moving to a point on the diametrically opposite side of the VSWR
circle. It shows a normalized load impedance as 2 j2. Moving from this point by
3.15 l toward ... transformer is also presented
along with a few examples to match resistive loads. Impedance measurement via the
voltage standing wave ratio is then discussed. Finally, the Smith chart is introduced
to ... Solutions to the transmission line equation are then
constructed in order to understand the behavior of the propagating signal. This is
followed by the concepts of sending end impedance, re¯ection...
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Sử dụng lò vi sóng
Ngày tải lên :
17/09/2013, 20:10
... - 10:06 AM
Lò nấu vi sóng
Lò Vi sóng (Microwave oven - sóng cực ngắn) hiện nay đã ngự trị trong bếp của nhiều gia
đình cũng như tại công sở, trường học…. Dân giầu có thì sắm một lò gắn vào tường ... fries) trong lò vì chất béo quá nóng
gây cháy.
- Tránh mọi hư hao cho cửa lò như đè lên cửa hoặc nhấc lò lên
bằng cánh cửa lò.
- Vài năm kiểm tra lò một lần coi có bị thất thoát sóng ra ngoài.
- ... cần lưu ý là lò vi sóng hiện nay rất an toàn cho người
mang máy điều hòa nhịp tim (pacemaker) vì các y cụ này đều được
che chở chống phóng xạ hoặc vi sóng.
© Copyright 2000-2003 Vinacomm, all...
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Mạch điện tử - Tách sóng
Ngày tải lên :
20/10/2013, 04:15
...
i
D
i
D
v
D
v
D
t
t
Hỗnh 4.2. ỷc tuyóỳn cuớa diode vaỡ õọử thở
cuớa tờn hióỷu vaỡo ra khi laỡm vi ỷc ồớ chóỳ õọỹ C
E
o
64
4.2.2.2 Taùch soùng bión õọỹ duỡng phỏn tổớ tuyóỳn tờnh tham sọỳ
...
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Microstrip bộ lọc cho các ứng dụng lò vi sóng RF (P1)
Ngày tải lên :
24/10/2013, 16:15
... wavelengths between 1 m
(10
–6
m) and 1 mm. Beyond the infrared spectrum is the visible optical spectrum,
the ultraviolet spectrum, and x-rays. Below the microwave frequency spectrum is
the radio ... tuning. Here the costs for the design and tuning can be reduced greatly by using
CAD, which can provide more accurate design with less design iterations, leading to
first-pass or tuneless filters. ... developments in this area are cer-
tainly being stimulated by increasing computer power. Another driving force for the
developments is the requirement of CAD for low-cost and high-volume production.
In...
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Microstrip bộ lọc cho các ứng dụng lò vi sóng RF (P2)
Ngày tải lên :
24/10/2013, 16:15
... ports of the network NЈЈ ; and all the S submatrices con-
tain the corresponding S parameters. Obviously, p + c = M
1
and q + c = M
2
. It is
[aЉ]
q
[aЉ]
c
[SЉ]
qc
[SЉ]
cc
[SЉ]
qq
[SЉ]
cq
[bЉ]
q
[bЉ]
c
[aЈ]
p
[aЈ]
c
[SЈ]
pc
[SЈ]
cc
[SЈ]
pp
[SЈ]
cp
[bЈ]
p
[bЈ]
c
b
i
ᎏ
a
j
a
1
a
2
Ӈ
a
M
S
1M
S
2M
Ӈ
S
MM
... at port 2 of the network NЈ and port 1 of the network N Љ
when SЈ
mn
and SЉ
mn
are evaluated individually.
2.8 NETWORK PARAMETER CONVERSIONS
From the above discussions it can be seen that for ... composite
network is given simply by the sum of the short-circuit admittance matrices of the
individual networks.
Analogously, the networks of Figure 2.3(b) are connected in series at both their
input...
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Microstrip bộ lọc cho các ứng dụng lò vi sóng RF (P3)
Ngày tải lên :
28/10/2013, 23:15
... the same 3 pole
Butterworth lowpass prototype as that used previously in Section 3.3.1, Figure
3.15(b) illustrates a bandpass having a passband from 1 to 2 GHz obtained using the
element transformation.
3.3.4 ... = 1 to n (3.24)
g
n+1
= 1.0
For convenience, Table 3.1 gives element values for such filters having n = 1 to 9.
As can be seen, the two-port Butterworth filters considered here are always sym-
metrical ... be chosen.
3.2.2 Chebyshev Lowpass Prototype Filters
For Chebyshev lowpass prototype filters having a transfer function given in (3.9)
with a passband ripple L
Ar
dB and the cutoff frequency...
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Microstrip bộ lọc cho các ứng dụng lò vi sóng RF (P4)
Ngày tải lên :
28/10/2013, 23:15
... previous expressions for
re
are
obtained based on the quasi-TEM or quasistatic approximation, and therefore are
rigorous only with DC. At low microwave frequencies, these expressions provide ... expressions also provide accuracy better than one percent. If more accurate
values are needed, an iterative or optimization process based on the more accurate
analysis models described previously can ... 4.10(h).
These microstrip patch resonators can be analyzed as waveguide cavities with mag-
netic walls on the sides. The fields within the cavities can be expanded by the
TM
Z
nm0
modes, where z is perpendicular...
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Microstrip bộ lọc cho các ứng dụng lò vi sóng RF (P5)
Ngày tải lên :
07/11/2013, 21:15
... Semilumped Lowpass Filters Having Finite-Frequency
Attenuation Poles
The previous two types of microstrip lowpass filter realize the lowpass prototype
filters having their frequencies of infinite ... (b)
can only be electrically equivalent to the combline filter in the vicinity of the mid-
band frequency, and its stopband behavior is different from that of the combline fil-
ter.
Similar to the ... inductances L
1
, L
3
, and L
5
block transmission by
having infinite series reactance, whereas the capacitance C
6
shorts out transmission
by having infinite shunt susceptance.
A microstrip filter...
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