Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Vol. 63, No. 15
Experimental study of microwave resonator
tuning system*
Pinnacle
Yang Juan†
Tang Mingjie Luoli Tao Wang and right
(Astronautics, Northwestern Polytechnical University,Xi'an710072)
(2014Year1Month9Date of receipt; 2014Year3Month18Date of receipt of revised)
Round table resonant cavity and microwave generation and transmission apparatus and the
outside world may form a separate microwave resonator system.Since the pressure difference on
the wall of electromagnetic effects,Round table cavity may produce a net electromagnetic
force,This need to give proof from the experiment.To this end the first response to a
separate system into the microwave resonator Experimental study on-line tuning,The system
time is in the resonant state,It is important to ensure that the net proved the existence of
electromagnetic force.To this end,In this paper, round table resonator tuned for low-signal
test,In conjunction with the tuning element,Accurate debugging2.45 GHz Resonant state
frequencies,Influence of temperature on the resonant state analysis.Experimental results show
that the resonant frequency of the microwave resonator2.44895 GHz, Quality factor117495.0823,And
when the cavity wall temperature rise The resonant frequency is reduced, the quality factor
to periodic oscillations.
Key words: Apply electromagnetism, electromagnetic transmission, microwave radio equipment and
facilities
PACS:41.20.-q, 41.20.Jb, 07.57.-c
DOI: 10.7498 / aps.63.154103
1 Lead Speech
Free
space
using
electromagnetic
pressure generating electromagnetic form
Thrust has been confirmed by research
papers published [1,2], Which generates thrust
system is an open system relatively free space, if
the microwave resonator system electromagnetic
pressure
difference
can
generate
an
electromagnetic force, would give rise to a new
type of the propulsion program.
Microwave resonator system consists of
a round table and a microwave resonant
cavity production Health and transport
equipment, of which the resonator round
table
is
the
main
source
of
net
electromagnetic
force.
Round
table
resonator made of a metal conductor, if the
electromagnetic resonance phenomenon is
input to the cavity, the body in any
position of the reflected wave and the phase
of the incident chamber are equal, the total
electric field and magnetic field amplitude
is superimposed directly incident and
reflected waves, thus the total electric and
magnetic fields, respectively, greater than
the
amplitude
of
the
incident
wave
amplitude.
then
appropriately
selected
resonant mode, so that the front and rear
ends of the wall surface of the cavity
produce electromagnetic pressure difference,
resonator will produce a net electromagnetic
force distribution in the axial direction.
increase the pressure difference exists and
electromagnetic field amplitudes cavity
resonator round table will produce a net
154103-1
Physical Science Daily
(2014)
electromagnetic force
[3-5]154103
.
Acta Phys. Sin.
To prove a round table resonator net
electromagnetic force experimentally the
existence
of
In
need
of
an
external
independent and microwave resonator system
Vol. 63, No. 15
Experimental Research tuning, so that the
system always in resonance. In this paper,
a round table of low signal tuned resonator
experiments, in conjunction with the tuning
element accurately debug the state of 2.45
GHz resonance frequency, and experimental
analysis of temperature on the resonant
state the impact of the system parameters
are given power characteristics in real
conditions.
2 microwave resonator consisting of
Round table by the microwave resonator
cavity formed system is shown1 Shown, it is
a precise frequency tracking system,
made of iron Lithium battery conditioning
power,
signal
source,
amplifiers,
waveguides, round table resonant cavity
detector and radiator, of which the signal
source and amplification When constituted
solid source system to work, the signal is
converted to electrical energy source
Milliwatt, in 2.45 GHz electromagnetic
energy input to the amplifier The amplifier
in the power of action to milliwatts to
hundreds of watts of energy amplification
energy along the waveguide transmission to
a round table resonant cavity. When the
frequency of natural resonant frequency and
the signal source output of round table is
the same resonator, the electromagnetic
wave in a round table resonant cavity
resonator, a detector signal is maximum
value of the state, a round table may have
an axial cavity net electromagnetic force
F. On the contrary, when a round table and
a cavity resonance frequency signal source
output frequency is not at the same time,
the detector signal is at a very low level,
Then continue to change
*National Natural Science Foundation of China(Approval number: 90716019)Project supported by.
†Corresponding Author. E-mail: yangjuan@nwpu.edu.cn
©2014 Chinese Physical SocietyChinese Physical Society
154103-2
http://wulixb.iphy.ac.cn
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Variable output frequency signal source,
and a round table until the cavity
resonance frequency coincide, then the
detector signal reaches the maximum value,
the
electromagnetic
resonator
system
resonance, round table cavity may produce a
net electromagnetic force. Literature [6]
Theoretically discussed the resonator quality
factor and net electromagnetic force is
proportional to the round table, and thus
accurate resonant cavity and having a high
quality factor is a key factor in a net
electromagnetic force at its resonant frequency.
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8ܸ ஊ
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Drawing1Microwave resonator
system structure diagram
Vol. 63, No. 15
Taiwan cavity resonance at 2.45 GHz in the
TE011 mode.
3.2 Match guarantee system based on
conditions
For the FIG.1 Microwave resonator
system shown, a round table resonance
Cavity waveguides and three solid source
equivalent impedance equal system of To
match, this time completely absorbed
microwave power resonator [ 8]. When the
system does not match the power output of
the microwave cavity with a reflective,
Then need to generate a cavity near the new
reflected wave, it just reflected wave
amplitude and phase, cancel each other, so
as to achieve the system match. Produces a
reflected wave of this new approach is to
use a rectangular microwave coupling window
and double spiral As shown dispenser2 , In
which a rectangular window with a microwave
Ԧܸη Ղ
coupling
between
the
resonator
and
waveguide circular table, double spiral
ᣣ
deployment is used in a microwave coupling
࠱
ܸ
between the rectangular windows and solid
ܸܸ
8
source. Adjust the appropriate rectangular
micro
‫ڍ‬গ ܸ
Wave coupling window sizeL1,L2 And twin screw dispenser
two screws
Depth L3,L4It can make the microwave
resonator system to achieve
accurateMatching state.
oscillation frequency of the applied power
frequency ω and ω0 RLC circuit coincides,
resonance, electromagnetic energy is the
largest closed waveguide cavity resonance
circuit in principle stored and the same,
and thus the resonance condition occurs as
follows: 1) cavity
3 Guarantee microwave
resonator system resonant
state Condition
3.1 Based resonator structure to
ensure that the conditions of
Electromagnetic waves transmitted into
the waveguide cavity closed period, both
energy storage field, can store magnetic
energy, which cavity can be equivalent to a
low-frequency RLC circuit. When the free
The maximum power and maximum (energy
)
1 n
equal;2) the presence of the cavity +
4 2
154103-3
Physical Science Daily
(2014) 154103 ԥ ᛃ ܸ
Acta Phys. Sin.
Vol. 63, No. 15
Drawing2Microwave resonator matching components(A)
Rectangular microwave coupling window; (B)
Twin-screw dispenser
ܸ8
L
4 Low Signal frustum cavity
L
L
debugging
L
4.1
Debugging principle
(A)
(B)
)
Or (1 n
Pure standing wave,n= 1, 2, 3·;
2
+
2
3)Cavity
Equal to the inductance and capacitance of
anti-anti.Theoretically, microwave resonant
cavity resonance
Vibration
mode
significantly
in
has
order
diversified
to
generate
an
electromagnetic force needed In the round
table to select the equivalent resonant
cavity, high quality factor TE011 Mode. A
microwave theory [7],TE011It can only exist
in a cylindrical mold Resonant cavity.
And
for
the
round
resonator,TE011Electromagnetic
table
special
mold Zheng equation can not be solved.
But if a round table cavity side wall
mining
TE01
microwave
mode
coupling
rectangular
will
excite
waveguide
resonant
cavity in a round table similar cylindrical
resonator mode of the electromagnetic field
ᅾ ॎ
࠮
ฉ
In the resonant mode and the resonant
frequency determined conditions,
according to the resonance
Cavity
theory,
we
can
design
and
processing of the round table resonant
cavity. In fact,
Because
of
the
design
calculations,
fabrication and assembly errors that could
cause actual cavity Offset from the ideal
resonant structure; ambient temperature
changes and another cavity surface skin
depth heat effect on the radial and axial
dimensions of the cavity can also lead to
changes, these uncertainties affect not
only the resonant frequency of the resonant
cavity, also affects the quality of factor.
and thus to determine the specific
structure of the cavity resonance frequency
and quality factor resonator according to a
debugging test method return loss.
Return loss is defined as
Pr
distribution TE011, TE011 and therefore is
used here to describe the use of a resonant
mode. A microwave resonant cavity theory,
literature
[6]
To
determine
the
electromagnetic resonator
Structure system frustum cavity, thereby
theoretically guarantees round
Lr= 10 lg
154103-4
P1
,
(1)
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Among themPrReflected from the cavity of
power,P1As an input to the harmonic Power
oscillator cavity definition quality factor
Q of the total storage resonant cavity
electromagnetic field within a period 2π
times the energy loss ratio, that is,
W
ω0 W
Vol. 63, No. 15
Before, the first network analyzer short
calibration, which reflectance measurements
are normalized. Debugging device and then
connected
standby,
measurement
resonant
in
resonant
frequency,
return
cavity
quality
loss
near
the
factor
is
determined by the size of the replacement
cap, rectangular microwave Coupled windows
and
Q=2π
p LT 0
=
,
(2)
pL
Among themWIntraluminal electrical, magnetic
total energy storage,pLThe average loss for
the resonatorPower consumption,T0Resonance
cycle.
Drawing3 Shows a typical return loss
test curve,Curve
the
deployment
of
Lr
min
Lmin
f1f0f2
Drawing3Return Loss test curve
analyzer via microwave transmission cable
resonator connection. Debugging
࠱ܸ ᄦ
ܸ
ᑿ
twin
screw
adjustment screws deep
Degree adjustmentTest, To determine the
resonance at 2.45 GHz, with the highest
Structural
combination of
merit.
The lowest point of the resonant state,
a frequency corresponding to the
resonance frequency f0.
Quality factor according to To calculate,Its
f0
f0
the formulaQ=
=
f2-f1
Δf
InΔf=f2-f1Resonance frequency
bandwidth.Visible,Resonant frequency
The ratio of the resonant frequency
bandwidth determines the quality factor.
As shown4 , The microwave resonator
tuning system consists of a network
analyzer,
the
rectangular
microwave
coupling window, double spiral dispenser
and round table resonator consisting of a
round table and the side wall cavity size
cap structure, in which the network
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Լ
ܸ
a
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Ο‫ܞ‬
࠱ܸ ܸ Я ܸ ງ ए
ܸܸѬܸ
가 ܸܸ ܸ ܸ Ռ ܸ
࠱ܸ ᄦ
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Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Vol. 63, No. 15
Drawing4Microwave resonator tuning system
4.2 Commissioning results and
analysis
4.2.1. Debugging round table resonator
1) cover a combination of different sizes.
With 7 sets of different size cap retraction depth,
you can get 49 kinds of different combinations of
retraction for the size of the end surface at
different depths, choose the large end after
commissioning retraction depth 4 mm, small
end face retraction depth 12 mm for the best
combination, then the resonant frequency closest
to 2.45 GHz, and the quality factor most
High its return loss curve is shown5 (A), the
draw resonance frequency of 2.4500 GHz,
resonant bandwidth of 2.5×10-3GHz, quality
Factor 976.9753.
2) The rectangular structure of different
microwave coupling window. Adopted 15
different sizes of rectangular microwave coupling
window, in the best combination of size, based
on the end cap, through commissioning, and
ultimately selectedL1= 43.34 mm,
L2= 31.78 mm rectangular microwave coupling
window of the best, then the resonant frequency
closest to 2.45 GHz, and the highest quality
factor. Its return loss curve is shown 5 (B), the
draw resonance frequency
2.4500 GHz, resonant bandwidth of 1.6×10-3GHz,
quality factor
1512.887.
4.2.2
And the double helical structure
of the deployment of the best
round table resonator debugging
Based on the above circular table in
the debug resonator, the increase in twin
screw dispenser for debugging, adjust
double screw insertion depth until the best
results are shown debug5 (C), the resonance
frequency at this time is closest to 2.45 GHz, and
the highest quality factor. Draw resonance
frequency
2.44895 GHz, resonant bandwidth of 2.0843×105
GHz, quality
Factor of 1.175 × 105.
154103-6
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Vol. 63, No. 15
0
-1.0
-2.0
Lr/dB
Lr/dB
-4
-3.0
-4.0
-8
-12
(A
)
2.44
f0= 2.4500
GHz
Df= 2.5T10-3 GHz
2.45
2.46
2.47
(B
-16)
2.43
2.44
f/
GHz
f0=2.45 G H z
Df= 1.6843T10-3
GHz
2.45
2.46
2.47
f/ GHz
0
Lr/dB
-10
-20
-30
(C
)
2.4484
-40
f0=2.44895 G H z
Df= 2.0843T10-5
GHz
2.4488
2.4492
2.4496
f/ GHz
Drawing5Return Loss test curve(A)Optimal size end combinations; (B)Best of rectangular microwave
coupling window; (C)Best screw depth twin screw dispenser
4.3 Effect of temperature on the
cavity resonance condition
4.3.1 Experiment law
According Return Loss test curve
shows that the higher the quality
factor, The
narrower
the
resonance
bandwidth and resonant frequency and
quality
factor
more
sensitive
to
deformation of the cavity. For this reason
a heating source in the outer wall of the
cavity to produce the effect of thermal
deformation of the cavity structure.
The heat source were placed small
endFace, big face and the side wall
surface, Measure
The amount of return loss, and then
determine the resonant frequencyf0And a
minimum return lossLrmWith the heat
source temperature changes as shown in6
Figure6 (A), (b)
As a heat source placed small end test
results show that the temperature shown
from32.5
Between oscillation and the amplitude
basically
unchanged
from
FIG.6 Also
calculate Publisher The quality factor,
the results show that the heat source is
placed in different locations, the highest
Quality factor are 120,000, the lowest
quality factor are 40,000.
4.3.2 Analysis of experimental phenomena
Resonant
frequency
falling
This
phenomenon can be a microwave cavity The
perturbation theory [8]From electromagnetic
theory to explain when the cavity wall by
the
perturbation,
the
following
relationship:
ω-ω0 (we-wm )·Δv
ω0 =
W
◦
,
(3)
CWhen raised to 49.9 ◦C, the resonant frequency is
reduced from 2.4495 GHz to 2.44885 GHz, minimum
return loss between -54 and -17 dB oscillation, and
154103-7
Physical Science Daily Acta Phys. Sin. Vol. 63, No. 15
154103 decreases.
oscillation (2014)
amplitude
Where, ω is the
the
Figure6 (C), (d) a heat
Source placed large end outer test results
show that the temperature shown from29.5
◦
C rises to40.4◦CWhen
the
resonance
frequency reduction from 2.44970 GHz
Small to2.449375 GHz, minimum return loss43 and-17
oscillates between dB, and the amplitude and
then decreased. Figure 6 (E), (f) as a heat source
placed outside the wall test results show that the
temperature shown from 28.7
◦
C rises to32.8◦CWhen
the
resonance
frequency reduction from 2.44935 GHzSmall
to 2.44915 GHz, minimum return loss at -42
and -17 dB
resonant frequency
perturbation round after; ω0 is the
resonant
frequency
perturbation
round
before; we, wm were average power density
and
the
magnetic
energy
density
perturbations at; Δv to volume changes,
when the cavity wall when concave , Δv <0,
when the wall-convex, Δv> 0;. W after
total average resonant cavity perturbation
electromagnetic energy table1 It explained
the situation of various disturbances
varying frequency.
Table1Wall-perturbation frequency changes
Perturbation
nature
Perturbation region
Strong magnetic
field, a weak electric
field
A weak magnetic
field, strong
electric field
154103-8
Private perturbation Outbound
perturbation
Δv <0
Δv>0
ω>
ω0ω
<ω0
ω
<ω0ω
> ω0
Acta Phys. Sin.
Physical Science Daily
(2014) 154103
2.4495
Fifte
-20
en
2.4494
-25
2.4493
-30
2.4492
-35
Lrm/
DB
f 0/
GHz
2.4496
Vol. 63, No. 15
2.4491
-40
2.4490
-forty
Five
-50
2.4489
(A
)
32 34 36 3,840,424,446,485,052
2.4488
T/C
T/C
2.44970
Fifte
en
-20
2.44965
-25
2.44960
-30
2.44955
-35
2.44950
-40
2.44945
-forty
Five
-50
-55
Lrm/
DB
f 0/
GHz
2.44975
2.44940
2.44935
(C
)
28
30
32
34
36
38
40
(D
)
28
30
32
T/C
34
36
38
40
42
T/C
-Fifteen
2.44935
-20
2.44930
-25
f 0/
GHz
2.44940
Lrm/
DB
-30
2.44925
-35
2.44920
2.44915
(B
)
-55
32 34 36 3,840,424,446,485,052
-40
(F)
(E)
28
29
30
31
32
33
-forty Five
28
29
30
31
34
T/C
32
33
34
T/C
Drawing6Measurement system resonant frequency and a minimum return loss varies with temperature (A),
(b)The outer wall of the heat source placed small end; (C), (d)The outer wall of the heat source placed
in the large end face; (E), (f)Placed on the side of the outer wall of the heat source
resonant
field, a weak electric field perturbation at the
cavity electromagnetic field distribution
outward. The above table shows that, after the
[3]Found
resonant
According
that
to
in
round
the
table
cavity
inner
wall
surface of the cavity is always lower than
frequency
perturbation
less
than
the
resonant frequency perturbation ago.
the average electric field strength and
Return loss is a phenomenon of alternating
magnetic field strength is always higher
size network analyzer Scanning frequency can not
than the average of the cavity in the
be continuously caused, the network analyzer
cavity normal working hours, the skin depth
can
heat loss within the cavity so that thermal
frequency points.Drawing7 (A) shows the actual return
loss curve, assuming two adjacent frequency points isf1,f2.
deformation, In bolted thermal expansion
that the wall being outwardly convex, this
volume change is very small. In summary,
this condition belong in a strong magnetic
154103-9
only
give
Return
loss
value
scanning
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
With increasing heating time, the
round
table
cavity
volume
continues to expand, Then t1,t2,t3And
t4, the actual return loss curve
gradually shifted to the left, the
resonant frequencies of f1, f01,
f02,
f2,
the
lowest
returnWave
loss values areLminHowever, due to
the
network
analyzer
scanning
frequency is unable to continue, the
return loss curve and the actual curve
recording can not be consistent, that is,
when the return loss curve locatedf1And
between
f2,
recorded
the
curve
the
distortion,
scanning
actually
presence
only
frequency
give
of
letter
pointInterest
Figure7 (B) gives the network analyzer
return loss curve recording, scanning
frequency
interval
Δf=f1-
f2DefinitionLrif1,Lrif2Heating for a
time at the actual curve i at a
frequency
return
of
loss
f1,
and
return
loss,
minimum
value
when the value of f2, where i =
1, 2, 3, 4. forAt time t1, the
network
analyzer
records
real
curve, the resonant frequency
15410310
Vol. 63, No. 15
Acta Phys. Sin.
Physical Science Daily
(2014) 154103
Vol. 63, No. 15
Ratef1,Minimum
return
lossLr1f2.Fort2Time,The internetTest curve
distortion analyzer record,That test is
still
resonant
frequencyf1,Insteadf01,Minimum Return Loss
valuesLr2f2.
The actual minimum return loss should
For the time t3, the test curve network
analyzer record resonant frequency
Tof2,Insteadf02,Minimum Return Loss
valuesLr3f1.
Gradually increased -38 dB; when the heat
For the moment t4, network analyzer records
real curve, the resonant frequency f2, the
minimum return loss Lr4f 1. Thus, due to
the presence of sweep frequency interval,
only on the scan frequencies only return
loss measurement curve realistic, in
addition to measurement curve distortion
are present, it should be removed. Thus
FIG.6 (B), (d) and (f) given by
When, from -42 dB return loss down to -53 dB
and then increased to
be addressed as shown in curve8 Shown
Curve.
From Fig.8 Available, when the heat
source is placed small end, the return
loss
source is placed large end
from -53 dB to
Lr
-About 44 dB; when the heat source placed in the
side walls, the return loss oscillation changes,
but remain at -40 dB or less. Thus available,
influence resonator quality factor reduction
(return loss increases), the main factor is the
small end temperature.
Lr
Lr1f1
Lr1f1
Lr4f2
Lr3f2
Lr2f1
t
t
t
t
D
t4>t3>t2>t1
f
t4>t3>t2>t1
(A
)
f
t
t
D
f
Lr1f2
Lr4f1
t
f
f
t
Lr2f2
Lr3f1
Lr1f2
Lr4f1
Lr3f2
Lr2f1
Lr2f2
Lr3f1
Lr4f2
f
(B
)
f
f
Drawing7Return loss curve(A) Actual curve; (B)Network analyzer sweep display curve
-40
-38
-44
Lrm/
DB
Lrm/
DB
-42
-46
-48
-50
-52
(B)
(A)
-54
36
40
44
48
52
28
32
36
T⊳C
T⊳C
-39.5
-40.5
Lrm/
DB
32
-56
15410311
(C)
40
Physical Science Daily
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Acta Phys. Sin.
Vol. 63, No. 15
-42.5
28
29
30
31
32
33
T⊳C
Drawing8The actual minimum return loss variation with temperature(A) Small end; (B) Large end; (C)
Sidewall
15410312
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Powered amplifier, and constantly adjust
the output frequency of the signal source
to make the detector signal and keep the
maximum, then the system resonance.
Reference frustum cavity low signal
results can be predicted in the actual
power conditions the wall set frustum
cavity skin depth of the microwave heating
caused cavity expansion will make the
system detuned, so that a detection signal
decreases, and therefore actual power
conditions of the system Debugging should
be a signal to the resonant state detector
marked the largest system after the system
is powered on, the source first output
center frequency 2.45 GHz, and then
discovered that the detection signal is
decreasing. After so the system is turned
on, the signal source output frequency
should be the center frequency began
reduced in order to obtain the maximum
value of the detection signal, down-step
experiment is 10 kHz.
5 Microwave resonator system
debugging under conditions of
actual power
5.1
Debugging process
Drawing9 Microwave resonator system
under real conditions of power,Wherein
lithium iron conditioning power on and off,
solid source of switch and frequency by
infrared remote control, and there is solid
source monitor output and reflected power
indicator on the power lithium iron
conditioning system operation as follows:
Open iron lithium battery conditioning
supply, respectively, to the signal source
and discharge
ႃ ԍ
᛫
V
૝ ฉ
8
ԥ ᛃ
ܸ8
Vol. 63, No. 15
ᥑ ૝
૝૝
ܸ
‫ڍ‬গ
ܸ
ଊ
᧫
η Ղ
ܸ
ᥑ ૝ҫ
ႃ
ႃ ܸ
૝҄ᄤ
8ܸ
ஊ
ᅾॎ ॲ
Ռܸ
ฉ૝
‫ړ‬Լ ܸ ૝ ᑿ
૝૝ ႃ
૝
ܸ ܸܸ ܸ
ඵ
шԂ8
Drawing9Microwave resonator system debugging power under real conditions
5.2
cavity detuning detector
Debugging results
5.2.1 Resonant state detection
2.0
U= 0.8
Umax gives
system
Drawing10 Under the
true
ᣥѣ࠮ ဋ
ܸ ࠮࠮ ဋ ᄱ
power source
output frequency Seen from
ܸ
the figure and the measurement curve
detection
signal
voltage
relationship,After power source output
ᣥѣ࠮ ဋ ࠮ ࠮
frequency 2.45 GHz unchanged,
due to the
ଌ ࠮ ܸ ࠮࠮
ဋ
heat cavity resonance frequency decreasing,
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ᣥѣ
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
detection signal U "0.8Umax resonance when
the system is in good condition. Therefore,
the actual down, the need to ensure the
detector signal is always at 1.7 V or more.
The feedback signal is decreasing.
After quickly reduce output frequency
signal source Rate, the output frequency
is constantly approaching the resonant
frequency resonant cavity tends, so the
detector rising feedback signal. When the
signal
source
output
frequency
substantially equal to the resonant
frequency, the resonant cavity is in good
condition, the feedback signal detector
tends to be a great value. here believe a
U/V
1.6
0.8
0.4
0
5.2.2 cavity surface temperature change
In the real power, the thermal effect
causes the temperature of the cavity wall
cavity within the skin depth increases, so
the study of the cavity surface temperature
࠮ ဋ
࠮
࠮
࠮
ܸ
ܸ
࠮
࠮
ဋ
1.2
2.4492
2.4494
2.4496
2.4498
Vol. 63, No. 15
2.4500
f/
GHz
Drawing10 Relationship between the signal
source and the detector output signal frequency
between
15410314
Variation
help
verify
whether
the
microwave
resonator
resonance
shape
State. To this end, we measured with a
thermocouple as shown11 Cavity surface
shown
The
surface
temperature
at
different
locations.
Temperature
measurement
process
should
continue
Reduce the output frequency of the
signal source to ensure that the
detector signal and keep The maximum
value2.1 V at that time to ensure that the
resonator is resonated measurement point
temperature change over time as shown12 As
shown in diagram indicating that the
temperature at the center of the small end
first began to rapidly rise, followed by
temperature measurement points at other
positions are also beginning to heat up,
and the temperature close to each other, it
was obvious that the end face of the center
as a heat source.
Acta Phys. Sin.
Physical Science Daily
(2014) 154103
Vol. 63, No. 15
D
6 Knot Theory
D⊳
H
D⊳
D
Drawing11 Measurement point position
70
࠱ܸ ᭧1‫ܫ‬ພए
࠱ܸ ᭧2‫ܫ‬ພए
Ο ‫ܞ‬3‫ܫ‬ພए
60
T/C
50
40
Ο ‫ܞ‬4‫ܫ‬ພए
ܸܸ ᭧5‫ܫ‬ພए
ܸܸ ᭧6‫ܫ‬ພए
30
20
0
20
40
60
80
100
t/ S
Drawing12 Cavity surface temperature change
with time
To explain the temperature variation,
the first to be interpreted according to
the
theory
of
electromagnetic
wave
propagation equation round table resonant
cavity. In order to obtain the maximum
electromagnetic thruster force, requiring
electromagnetic waves to the small end cutoff
at
a
transmission,
Deadline
round
the
table
wavelength
√
resonator
close
On
2
In this paper, the rectangular waveguide
transmission line, coupled windows and double
screw adjustment Adapter to match the
element, use a network analyzer to round
table resonant cavity microwave resonator
system conducted experiments debugging, and
get the ideal resonant state that the
resonant frequency of 2.44895 GHz, the
quality factor of up to 117,000, and find
the resonant frequency with the cavity
continue to lower the temperature increases
and return loss periodic oscillation
experiment phenomenon from the working
characteristics of the network analyzer
sweep starting, explain the reasons echo
oscillations
and
eliminate
distortion
return loss. For solid source of microwave
resonator systems to large end wall cavity
detector signal is a feedback signal, in
real power conditions, the infrared remote
control device to match the source remote
switch and down after frequency detector
signal remains the largest state in about
2.1 V, to achieve a precise tuning of the
entire microwave resonator system, so that
it can always be in resonance. Finally, the
major point of the cavity wall temperature
monitoring indicates small end cavity at
the
center
of
the
heat
the
most
significant, in line with the resonator
characteristics of the work. The experiment
It laid a good foundation for further
independent microwave resonator system
thrust measurement and dynamic experiments.
Reference
Wavelengthλ=λc,Group
1-(λ/λc) = 0.And
velocityvg=c
In the large end of the required
wavelength of electromagnetic waves to
free-space wavelength
√
λ=λ0,Group
velocityvg=c 1-(λ0/λc)2.This
15410315
[1] Geo ff rey A. Landis 2000 Microwave Pushed Interstellar
Sail: Starwisp Revisited, AIAA3337
[2] Nakagawa T, Mihara Y, Komurasaki K, Takahashi K,
indicates that electromagnetic
Wave energy transfer to small end when all
deposited onto the metal surface from
Physical Science Daily Acta Phys. Sin. Vol. 63, No. 15
(2014)
154103
Sakamoto K, Imai T2004J. Spacecraft and Rockets41
Converted into heat
within
the skin depth
of the end face, while at the end face of
the large group velocity of electromagnetic
waves near the speed of light, all the
electromagnetic energy is reflected back to
the wall, so that in the ideal case, the
electromagnetic energy is not converted to
the skin depth of the inner wall surface
Thermal
Round
table
resonant
cavity
electromagnetic field numerical results
from existing microwave thruster view
[3],Calcd electromagnetic field strength in
the vicinity of the axis of the larger,
which have demonstrated the higher the skin
depth at the center of the end face of the
small heat, thus heating up rapidly, and
the temperature is higher than other
locations. In theory, the large end surface
skin Although not within the depth of the
electromagnetic energy deposition, but with
the extension of working hours thruster,
since the metal heat conduction large end
of the temperature will gradually rise.
15410316
151
[3] Yang J, Li P F, Yang L2011Acta Phys. Sin.60124101 (In
Chinese) [Yang Juan,Lee Peng Fei,Yang Le2011
Physical Science Daily60124101]
[4] Yang J, Wang YQ, Ma YJ, Li PF, Yang L, Wang Y,
He G Q 2013 Chin. Phys. B Twenty two
050301
[5] Yang J, Yang L, Zhu Y 2010 J. Northwestern Polytechnic University28 807 (in Chinese) [Yang Juan,Yang
Le,Zhu
Yu2010
Northwestern
Polytechnical
University28807]
[6] Qiu X M, Tang D L, Sun A P, Liu W D, Zeng X J 2007
Chin. Phys. B 16196
[7] Liao C En 1994Basic Technology of Microwave(Xi'an:
Xidian University Press) (in Chinese) [Liaocheng En1994
Microwave technology base(Xi'an:Xi'an University of
Electronic Science and Technology Press)]
[8] Li S F, Li C R, Song C L 2013Fundamental Course of
Optical Waveguide Theory, (Beijign: Publishing Hourse
of Electronics Industry) (in Chinese) [Li Shufeng,Li
Chengren,Song DynastyChang Lie2013Waveguide theory
based tutorial(Beijing:Electronic Industry Press)]
Physical Science Daily
(2014) 154103
Acta Phys. Sin.
Vol. 63, No. 15
Resonance experiment on a microwave resonator system*
Shi Feng Yang Juan†
Tang Ming-Jie Luo Li-Tao Wang Yu-Quan
(College of Astronautics, Northwestern Polytechnic University, Xi'an 710072,
China) (Received 9 January 2014; revised manuscript received 18 March 2014)
Abstract
A microwave resonator system is made, which has a tapered resonant cavity, a microwave source, and a
transmission device. Because of the electromagnetic pressure gradient on the tapered resonant cavity, a net
electromagnetic force along the axis of the cavity may be observed, which is needed to verify experimentally the use of
the independent microwave resonator system. It is also needed to keep the independent microwave resonator system in
resonating state, which is the important procedure to demonstrate the possibility of net electromagnetic force. Thus, a
low-signal resonating experiment on the tapered resonant cavity combined with resonating parts is completed to
accurately fi nd out the resonant frequency of 2.45 GHz and to analyze the in fl uence of temperature on the resonant
state. Experimental result shows that the resonant frequency and quality factor of the independent microwave resonator
system are 2.44895 GHz and 117495.08 respectively. When the temperature of the tapered resonant cavity wall rises, the
resonant frequency will be decreased and the quality factor changed separately.
Keywords: applied classical electromagnetism, electromagnetic wave propagation, microwave and
radiowave instruments and equipment
PACS:41.20.-q, 41.20.Jb, 07.57.-c
DOI: 10.7498 / aps.63.154103
*Project supported by the National Natural Science Foundation of China (Grant No. 90716019).
. † Corresponding author E-mail: yangjuan@nwpu.edu.cn
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