sơ đồ đấu nối 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, reection...
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Tài liệu RF và mạch lạc lò vi sóng P4 docx
Ngày tải lên :
15/12/2013, 11:15
... 3417,respectively.
Substituting these into (4.5.5), Q of this cavity is found to be 2106.
Circular Cylindrical Cavities
Figure 4.20 shows the geometry of a circular cylindrical cavity of radius r and height
h. It is đlled ... CIRCUITS
If the cavity is made of a perfect conductor and ®lled with a perfect dielectric then
it will have in®nite Q. However,it is not possible in practice. In the case of cavity
walls having a đnite ... ac
3
m
r
e
r
r
4:5:2
Permittivity and permeability of the dielectric đlling are given by e and m,
respectively; o is angular frequency; and R
s
is the surface resistivity of walls
which is related...
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Tài liệu RF và mạch lạc lò vi sóng P5 pptx
Ngày tải lên :
15/12/2013, 11:15
... reection coefđcient of 0.2 is
acceptable, circuits (iii) and (iv) can provide much wider bandwidth in comparison
with those of the previous example. This concept can be used to shape the reection
coefđcient ... between them. This device can be inserted at a
convenient point before the load. The impedance is matched by adjusting the
lengths of the two stubs. Of course, it does not provide a universal solution. ... 36:6269 O
; C
s
4:3453 pF
and,
X
p
91:29009 O A C
p
1:7434 pF
Example 5.10: Reconsider the previous example where Y
L
8 À j12 mS is to be
matched with a 50-ohm line. Complete or verify the...
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Tài liệu RF và mạch lạc lò vi sóng P6 ppt
Ngày tải lên :
15/12/2013, 11:15
... characteristic impedance versus normalized length of the
taper.
This design can be achieved by moving the zeros at u ặ1 and ặ4 into the
points ặ2 and ặ3, respectively. Hence,
QuCu
2
2
2
2
u
2
À ... Hence,
G
in
L
0
dG
in
1
2
L
0
e
Àj2bz
d
dz
ln
Zdz 6:7:3
Therefore, G
in
can be determined from (6.7.3) provided that
Zz is given. However,
the synthesis problem is a bit complex because, in that case,
Zz ... meet such
requirements. The chapter begins with the single-section impedance transformer
that provides perfect matching at a single frequency. Matching bandwidth can be
increased at the cost of...
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Tài liệu RF và mạch lạc lò vi sóng P7 pptx
Ngày tải lên :
24/12/2013, 17:15
... Z
o2
Z
2
Z
o2
b
2
a
2
7:6:22
Dividing (7.6.17) by a
1
and then using (7.6.21), we đnd
b
1
a
1
G
1
Z
1
Z
o1
Z
1
Z
o1
S
11
S
12
a
2
a
1
7:6:23
Now, dividing (7.6.18) by a
2
and then combining ... jb, the network becomes lossless. In that case,
S
11
S
12
S
21
S
22
!
0 e
Àjb`
e
Àjb`
0
!
Obviously, it is a unitary matrix now.
Example 7.19: Find scattering parameters of the two-port network ... illustration).
280
TWO-PORT NETWORKS
Current through 0.1 S is I
1
À I
N
0:0692V
1
. Using the current division rule,
current I
M
through 0.2 S is found as follows:
I
M
0:2
0:2 0:025
0:0692V
1
0:0615V
1
A
Hence,...
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Tài liệu RF và mạch lạc lò vi sóng P8 ppt
Ngày tải lên :
24/12/2013, 17:15
... devise some way to control its
attenuation around the cutoff. Expression for the propagation constant of a T-section
is listed in Table 8.1. In order to ®nd g of this T-section, we ®rst divide ... two-port network. Filters have been designed using active devices such as
transistors and operational ampliđers, as well as with only passive devices (inductors
and capacitors only). Therefore, these ... the load and source resistances are at 75 O
each.
The low-pass đlter designed in Example 8.7 provides the initial data for this high-
pass đlter. With m 3; g
L
0:62425, and g
C
0:9662, we đnd...
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Tài liệu RF và mạch lạc lò vi sóng P9 docx
Ngày tải lên :
24/12/2013, 17:15
... SIGNAL-FLOW GRAPH REPRESENTATION OF A PASSIVE
SINGLE-PORT DEVICE
Consider load impedance Z
L
as shown in Figure 9.18. It is a single-port device with
port voltage and current V
L
and I
L
,respectively. ...
Z
S
Z
o
V
ref
S
E
S
1
Z
S
Z
o
V
in
S
or,
V
ref
S
Z
o
Z
o
Z
S
E
S
Z
o
Z
S
Z
o
Z
S
V
in
S
Dividing it by
2Z
o
p
,we đnd that
V
ref
S
2Z
o
p
Z
o
Z
o
Z
S
E
S
2Z
o
p
Z
o
Z
S
Z
o
Z
S
V
in
S
2Z
o
p
Figure ...
Z
L
Z
o
V
ref
L
Z
L
Z
o
À 1
V
in
L
9:3:1
or,
V
ref
L
Z
L
À Z
o
Z
L
Z
o
V
in
L
À
L
V
in
L
9:3:2
After dividing it by
2Z
o
p
,we then use (7.6.15) and (7.6.16) to đnd that
b
L
L
a
L
9:3:3
where,
b
L
V
ref
L
2Z
o
p
9:3:4
a
L
V
in
L
2Z
o
p
9:3:5
and,
L
Z
L
...
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Tài liệu RF và mạch lạc lò vi sóng P10 docx
Ngày tải lên :
24/12/2013, 17:15
... Since G
o
is
approximately 14 dB, the remaining 2 dB can be set via G
S
and G
L
. If we design an
input-matching network that provides G
S
as 1.22 dB then we need an output-
matching network for ... values of load or source impedance) if one or both of these conditions are
violated. It means that the transistor can provide stable operation for a restricted
range of G
S
and G
L
. A simple procedure ... blocks of an electronic system. While
vacuum tube devices are still used in high-power microwave circuits, transistorsÐ
silicon bipolar junction devices, GaAs MESFET, heterojunction bipolar transistors
(HBT),...
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Tài liệu RF và mạch lạc lò vi sóng P11 ppt
Ngày tải lên :
24/12/2013, 17:15
... nonlinear active device. In addition, since the
device is producing RF power, it must have a negative resistance.
The basic principle of an oscillator circuit can be explained via a linear feedback
system ... the active device at the frequency of
oscillation. These two conditions are complementary to each other; i.e., if condition
(11.7.1) is satisđed then (10.7.2) is also satisđed, and vice versa. ... radians
per second per volt.
Mixer 1 Change of output phase equals change of input
phase.
Divider
1
N
N is the division ratio.
Phase detector K
d
K
d
is the slope of phase detector voltage to phase
characteristic...
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Tài liệu Các phương pháp và sơ đồ ghép nối vi xử lý - máy tính để điều khiển động cơ điện một chiều ppt
Ngày tải lên :
13/12/2013, 00:15
... dụng khối đồng pha (1). Vi c tạo tín hiệu đồng pha rất đơn giản vì
chỉ cần tạo điện áp dơng đa vào A/D của máy tính.
Hình 2.6 - Sơ đồ nguyên lý thực hiện đồng pha trong máy tính
Sơ đồ điều ... điện áp phần ứng cho máy điện thì sẽ sinh ra trong máy
điện một mômen làm quay rotor và máy điện một chiều làm vi c ở chế độ
động cơ. Ngợc lại khi quay rotor của máy điện một chiều và đặt điện ... Lớp: ĐKTĐ 2 K42
Chơng 2
các phơng pháp và sơ đồ ghép nối vi xử lý - máy tính để
điều khiển động cơ điện một chiều
Hiện nay do công nghệ mạch tổ hợp phát triển mạnh mẽ nên giá thành các...
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