This invention relates to a field-interacted device, and, more particularly, to such a device can be coupled with thermal, optical, electrical, magnetic, pressure or/and acoustic fields and the device can be solarcell, light sensor, thermal device, Hall device, pressure device or acoustic device which outputs self-excited multi-band waveforms with broad bandwidth. The invention also relates to a switch which can work under high speed condictions and a capacitor whose capacitance can be actively controlled.
The background includes information related to the present invention and the background information begins with the definitions of positive and negative differential resistors or respectively in short as PDR and NDR. The serially coupling of the PDR and NDR functioning as damper will also be discussed in the background information section.
Referring to [5], [34], [41, Vol. 1 Chapter 50] and [24, Page 402], the nonlinear system response produces many un-modeled effects: jump or singularity, bifurcation, rectification, harmonic and subharmonic generations, frequency-amplitude relationship, phase-amplitude relationship, frequency entrainment, nonlinear oscillation, stability, modulations(amplitude, frequency, phase) and chaoes. In the nonlinear analysis fields, it needs to develop the mathematical tools for obtaining the resolution of nonlinearity. Up to now, there exists three fundamental problems which are self-adjoint operator, spectral(harmonic) analysis, and scattering problems, referred to [32, Chapter 4.], [38, Page 303], [35, Chapter X], [37, Chapter XI], [36, Chapter XIII], [25] and [34, Chapter 7.].
There are many articles involved the topics of the nonlinear spectral analysis and reviewed as the following sections. The first one is the nonlinear dynamics and self-excited or self-oscillation systems. It provides a profound viewpoint of the non-linear
dynamical system behaviors, which are duality of second-order systems, self-excitation, orbital equivalence or structural stability, bifurcation, perturbation, harmonic balance, transient behaviors, frequency-amplitude and phase-amplitude relation-ships, jump phenomenon or singularity occurrence, frequency entrainment or synchronization, and so on. In particular, the self-induced current (voltage) or electricity generation appears if applying to the Liénard system.
Comparision Between Electrical and Mechanical Systems
Referred to [3, Page 341], the comparison between mechanical and electrical systems as the table (1):
the damping coefficient c in a mechanical system is analogous to R in an electrical system such that the resistance R, in common, could be as a energy dissipative device. There exists a series problem caused by the analogy between the mechanical and electrical systems. As a result, the damping term has to be a specific bandwidth of frequency response and just behaved an absorbent property as the previous definitions. The resistance has neither to be the frequency response nor absorbing but just had the balance or circle feature only. This is a crucial misunderstanding for two analogous systems.
Dielectric Materials
Referring to [31, Chapter 4, 5, 8, 9], [20, Part One], [21, Chapter 1], [8, Chapter 14], the response of a material to an electric field can be used to advantage even when no charge is transferred. These effects are described by the dielectric properties of the material. Dielectric materials posses a large energy gap between the valence and conduction bands; thus the materials a high electrical resistivity. Because dielectric materials are used in the AC circuits, the dipoles must be able to switch directions, often in the high frequencies, where the dipoles are atoms or groups of atoms that have an unbalanced charge. Alignment of dipoles causes polarization which determines the behavior of the dielectric material. Electronic and ionic polarization occur easily even at the high frequencies.
Some energy is lost as heat when a dielectric material polarized in the AC electric field. The fraction of the energy lost during each reversal is the dielectric loss. The energy losses are due to current leakage and dipoles friction (or change the direction). Losses due to the current leakage are low if the electrical resistivity is high, typically which behaves 1011 Ohm·m or more. Dipole friction occurs when reorientation of the dipoles is difficult, as in complex organic molecules. The greatest loss occurs at frequencies where the dipoles almost, but not quite, can be reoriented. At lower frequencies, losses are low because the dipoles have time to move. At higher frequencies, losses are low because the dipoles do not move at all.
Cauchy-Riemann Theorem
Referring to the [42], [12], [40] and [4], the complex variable analysis is a fundamental mathematical tool for the electrical circuit theory. In general, the impedance function consists of the real and imaginary parts. For each part of impedance functions, they are satisfied the Cauchy-Riemann Theorem. Let a complex function be
z(x,y)=F(x,y)+iG(x,y) (1)
where F(x, y) and G(x, y) are analytic functions in a domain D and the Cauchy-Riemann theorem is the first-order derivative of functions F(x, y) and G(x, y) with respect to x and y becomes
Furthermore, taking the second-order derivative with respect to x and y,
also F(x, y) and G(x, y) are called the harmonic functions.
From the equation (1), the total derivative of the complex function z(x, y) is
and substituting equations (2) and (3) into the form of (6), then the total derivative of the complex function (1) is dependent on the real function F(x, y) or in terms of the real-valued function F(x, y) (real part) only,
and in terms of a real-valued function G(x, y) (imaginary part) only,
There are the more crucial facts behind the (7) and (8) potentially. As a result, the total derivative of the complex function (6) depends on the real (imaginary) part of (1) function F(x, y) or G(x, y) only and never be a constant value function. One said, if changing the function of real part, the imaginary part function is also varied and determined by the real part via the equations (2) and (3). Since the functions F(x, y) and G(x, y) have to satisfy the equations (4) and (5), they are harmonic functions and then produce the frequency related elements discussed at the analytic continuation section. Moreover, the functions of real and imaginary parts are not entirely independent referred to the Hilbert transforms in the textbooks [18, Page 296] and [20, Page 5 and Appendix One].
Analytic Continuation
For each analytic function F(z) in the domain D, the Laurent series expansion of F(z) is defined as the following
where the expansion center z0 is an arbitrarily selected. Since this domain D for this analytic function F(z), any regular point imparts a center of a Laurent series [42, Page 223], i.e.,
where zj is an arbitrary regular point in this complex analytic domain D for j=0, 1, 2, 3 . . . . For each index j, the complex variable is the product of its norm and phase,
For each phase angle θj, the corresponding frequency elements are naturally produced, say harmonic frequency ωj. Now we have the following results:
Positive and Negative Differential Resistors (PDR, NDR)
More inventively, due to observing the positive and negative differential resistors properties qualitatively, we introduce the Cauchy-Riemann equations, [27, Part 1,2], [42], [12], [40] and [4], for describing a system impedance transient behaviors and particularly in some sophisticated characteristics system parametrization by one dedicated parameter ω. Consider the impedance z in specific variables (i, v) complex form of
z=F(i,v)+jG(i,v) (11)
where i, v are current and voltage respectively. Assumed that the functions F(i, v) and G(i, v) are analytic in the specific domain. From the Cauchy-Riemann equations (2) and (3) becomes as following
where in these two functions there exists one relationship based on the Hilbert transforms [18, Page 296] and [20, Page 5]. In other words, the functions F(i, v) and G(i, v) do not be obtained individually. Using the chain rule, equations (12) and (13) are further obtained
where the parameter w could be the temperature field T, magnetic field flux intensity B, optical field intensity I, in the electric field for examples, voltage v, current i, frequency f or electrical power P, in the mechanical field for instance, magnitude of force F, and so on. Let the terms
be non-zero and the same sign. Under the same sign conditions as equation (16) or (17), from equation (14) to equation (15),
should be held simultaneously. From the viewpoint of making a power source, the simple way to perform equations (16) and (17) is using the pulse-width modulation (PWM) method. The further meaning of equations (16) and (17) is that using the variable frequency w in pulse-width modulation to current and voltage is the most straightforward way, i.e.,
After obtaining the qualitative behavoirs of equation (18) and equation (19), also we need to further respectively define the quantative behavoirs of equation (18) and equation (19). Intuitively, any complete system with the system impedance equation (11) could be analogy to the simple-parallel oscillator as the
or in matrix form
where the function Fp(y) represents the generalized Ohm's law and for the single variable case, Fp(x) is the real part function of the impedance function equation (11), the “p” in short, is a “parallel” oscillator. Furthermore, equation (22) is a Liénard system. If taking the linear from of Fp(y),
F
p(y)=Ky
and K>0, it is a normally linear Ohm's law. Also, the states equation of a simple series oscillator in the
in the matrix form,
The iC, vl have to be replaced by x, y respectively. The function Fs(x) indicates the generalized Ohm's law and (25) is the Liénard system too. Again, considering one system as the figure (25), let L,C be to one, then the system (25) becomes the form of
To obtain the equilibrium point of the system (25), setting the right hand side of the system (26) is zero
where Fs(0) is a value of the generalized Ohm's law at zero. The gradient of (26) is
Let the slope of the generalized Ohm's law Fs′(0) be a new function as fs(0)
f
s(0)≡Fs′(0)
the correspondent eigenvalues λ1,2s are as
Similarly, in the simple parallel oscillator (22),
f
p(0)≡Fp′(0)
the equilibrium point of (22) is set to (Fp(0), 0) and the gradient of (22) is
the correspondent eigenvalues λ1,2p are
The qualitative properties of the systems (22) and (25), referred to [14] and [22], are as the following:
Thus, observing previous sink and source quite different definitions, if the slope value of impedance function Fs(x) or Fp(y), fs(x) or fp(y) is a positive value
F
s′(x)=fs(x)>0 (27)
or
F
p′(y)=fp(y)>0 (28)
it is the name of the positive differential resistivity or PDR. On contrary, it is a negative differential resistivity or NDR.
F
s′(x)=fs(x)<0 (29)
or
F
p′(y)=fp(y)<0 (30)
F
s′(x)=fs(x)=0 (31)
or
F
p′(y)=fp(y)=0 (32)
Liénard Stabilized Systems
Taking the system equation (22) or equation (25) is treated as a nonlinear dynamical system analysis, we can extend these systems to be a classical result on the uniqueness of the limit cycle, referred to [1, Chapter 22, 23, 24], [24, Page 402-407], [33, Page 253-260], [22, Chapter 10,11] and many articles [26], [19], [30], [28], [29], [16], [11], [39], [10], [15], [9], [13] for a dynamical system as the form of
under certain conditions on the functions F and g or its equivalent form of a nonlinear dynamics
where the damping function f(x) is the first derivative of impedance function F(x) with respect to the state x
f(x)=F′(x) (35)
Based on the spectral decomposition theorem [23, Chapter 7], the damping function has to be a non-zero value if it is a stable system. The impedance function is a somehow specific pattern like as the
y=F(x) (36)
From equation (33), equation (34) and equation (35), the impedance function F(x) is the integral of damping function f(x) over one specific operated domain x>0 as
Under the assumptions that F, g ∈ C1(R), F and g are odd functions of x, F(0)=0, F′(0)<0, F has single positive zero at x=a, and F increases monotonically to infinity for x≧a as x→∞ it follows that the Liénard's system equation (33) has exactly one limit cycle and it is stable. Comparing the (37) to the bifurcation point defined in the section ( ), the initial condition of the (37) is extended to an arbitrary setting as
where a ∈ R. Also, the
α≦a
the impedance function F(x) is
F(x)<0
The function derivative of F(x) should be
F′(x)=f(x)≧0 (39)
one part is a PDR as defined (27) or (28) and
F′(x)=f(x)<0 (40)
another is a NDR as defined (29) or (30), hold simultaneously. Which means that the impedance function F(x) has the negative and positive slopes at the interval α≦a.
Furthermore, one nonlinear dynamic system is as the follow
is a nonzero and nonlinear damping function,
g(x) (44)
is a nonlinear spring function, and
F(x, y) (45)
is a nonlinear impedance function also they are differentiable. If the following conditions are valid
then (41) or (42) has at least one periodic solution.
Frequency-Shift Damping Effect
Referring to the books [4, p 313], [35, Page 10-11], [25, Page 13] and [40, page 171-174], we assume that the function is a trigonometric Fouries series generated by a function g(t) ∈ L(I), where g(t) should be bounded and the unbounded case in the book [40, page 171-174] has proved, and L(I) denotes Lebesgue-integrable on the interval I, then for each real β, we have
where
e
i(ωt+β)=cos(ωt+β)+i sin(ωt+β)
the imaginary part of (46)
and real part of (46)
are approached to zero as taking the limit operation to infinity, ω→∞, where equation (47) or (48) is called “Riemann-Lebesgue lemma” and the parameter ω is a positive real number. If g(t) is a bounded constant and ω>0. it is naturally the (47) can be further derived into
where [a,b] ∈ I is the boundary condition and the result also holds if on the open interval (a, b). For an arbitrary positive real number ε>0, there exists a unit step function s(t), referred to [4, p 264], such that
Now there is a positive real number M such that if ω≧M,
holds. Therefore, we have
i.e., (47) or (48) is verified and hold.
According to the Riemann-Lebesgue lemma, the equation (46) or (48) and (47), as the frequency ω approaches to ∞ which means
The equation (51) is a foundation of the energy dissipation. For removing any destructive energy component, (51) tells us the truth whatever the frequencies are produced by the harmonic and subharmonic waveforms and completely “damped” out by the ultra-high frequency modulation.
Observing (51), the function g(t) is an amplitude of power which is the amplitude-frequency dependent and seen the book [24, Chapter 3,4,5,6]. It means if the higher frequency ω produced, the more g(t) is attenuated. When moving the more higher frequency, the energy of (51) is the more rapidly diminished. We conclude that a large part of the power has been dissipated to the excited frequency ω fast drifting across the board of each reasonable resonant point, rather than transferred into the thermal energy (heat). After all, applying the energy to a system periodically causes the ω to be drifted continuously from low to very high frequencies for the energy absorbing and dissipating. Again removing the energy, the frequency rapidly returns to the nominal state. It is a fast recovery feature. That is, this system can be performed and quickly returned to the initial states periodically.
As the previous described, realized that the behavior of the frequency getting high as increasing the amplitude of energy and vice versa, expressed as the form of
ω=ω(g(t)) (52)
The amplitude-frequency relationship as (52) which induces the adaptation of system. It means which magnitude of the energy produces the corresponding frequency excitation like as a complex damper function (43).
onsider one typical example, assume that given the voltage
v(t)=V0ej(ω
and current
i(t)=I0ej(ω
the total applied power is defined as
Let the frequency ω and phase angle β be as
ω=ωv+ωi
and
β=αi+αv
then equation (56) becomes into the complex form of
where real power π(ω, β, T) is
and virtual power Q(ω, β, T) is
respectively. Observing (46), taking limit operation to (57), (56) or (58),
the electric power P is able to filter out completely no matter how they are real power (59) or virtual power (60) via performing frequency-shift or Doppler's shift operation, where ωv, ωi are frequencies of the voltage v(t) and current i(t), and αv, αi are correspondent phase angles and T is operating period respectively. Let the real power to be zero,
which means that the frequency ω is shifted to
The total power (57) is converted to the maximized virtual power
Similarly,
the total power (57) is totally converted to the maximized real power
In fact, moving out the frequency element ω as the (61) is power conversion between real power (59) and virtual power (60).
Maximized Power Transfer Theorem
Consider the voltage source Vs to be
Vs=V0
and its correspondent impedance Zs
Z
s
=R
s
+iQ
s
The impedance of the system load ZL is
Z
L
=R
L
+jQ
L
The maximized power transmission occurrence if RL and QL are varied, not to be the constants,
RL=Rs (62)
where the resistor Rs is called equivalent series resistance or ESR and
Q
L
=−Q
s (63)
Comparing (62) to (63), the impedances of voltage source and the system load should be conjugated, i.e.,
Z
L
=Z
s*
then the overall impedance becomes the sum of Zs+ZL, or
The power of impedance consumption is
Let the imaginary part of P be setting to zero,
(Qs+QL)=0 (65)
i.e.,
Q
s
=−Q
L
or resonance mode. In fact, it is an impedance matched motion. The power of the total impedance consumption becomes just real part only,
From the basic algebra,
where Rs and RL have to be the positive values,
R
s, RL≧0 (66)
or
(Rs−RL)2=0
In other words, the resistance Rs and RL are the same magnitudes as
Rs=RL (67)
The power of impedance consumption P becomes an averaged power Pav
and the total impedance becomes twice of the resistance RL or Rs.
Z=2RL (69)
Let (63) be a zero, i.e., impedance matched,
Qs=QL=0 (70)
from (67), the total impedance and consumed power P are (69), (68) respectively. In other word, comparing the (1) to (70), it is hard to implement that the imaginary part of impedance (64) keeps zero. But applying the (2) and (3) operations into the form of (6), the results have been verified on the Cauchy-Riemann theorem, also it is a possible way to create the zero value of imaginary part of total impedance (64) or (6). Another way is producing a conjugated part of (64) or (6) dynamically and adaptively or order-∞ resonance mode. Consider two typical reactance loads, capacitor, shown in
It is a first objective of the present invention to provide a new structure of a field-interacted p-n junction device which can interact and couple with the fields.
It is a second objective of the present invention to provide the field-interacted p-n junction device with self-excited output.
It is a third objective of the present invention to employ the field-interacted p-n junction device into the application of solar-cell, light sensor, Hall device, switch, LED, switch or capacitor.
a has shown a characteristic curve of a typical tunnel diode;
b has shown the structure of a typical tunnel diode in which a heavily doped p-n junction is formed between a p-type and a n-type semiconductors;
c has shown the structure of a field tunnel diode by introducing the PDR and NDR concepts into the tunnel diode of
d has shown an embodiment of a multi-band waveforms;
e has shown an embodiment of a single-band waveform;
a has shown that the field tunnel diode of
b has shown that the field tunnel diode of
c has shown that the field tunnel diode of
a has shown the structure of a field tunnel transistor;
b has shown that the field tunnel transistor of
c has shown that the field tunnel transistor of
d has shown that the field tunnel transistor of
a has shown the structure of a typical LED;
b has shown the structure of an inventive LED;
c has shown an embodiment by employing the LED of
a has shown the structure of a field capacitor whose capacitance can be actively controlled; and
b has shown a circuit by employing the field capacitor of
According to the equations (12) above, the resistance variations can be generated by fields interaction. And, according to the equations (14) and (15), the positive differential resistor or PDR in short defined by (18) or (28) and the negative differential resistor or NDR in short defined by (19) or (30) can be generated by fields interaction in which the field can be temperature field T, magnetic field such as magnetic flux intensity B, optical field such as optical field intensity I, electric field such as voltage v, current i, frequency f or electrical power P, acoustic field, or mechanical field such as magnitude of force F, and so on, or, any combinations of them listed above. The PDR and NDR in the present invention are not limited to be produced by any particular field. A device having PDR or NDR property can be respectively called PDR or NDR in the present invention. A PDR can also be expressed as a device having PDR property in the present invention and a NDR can also be expressed as a device having NDR property in the present invention.
According to the equations (14) and (15), the reactance variations can be described by the resistance variations in an electrical system, in other words, unlimited resistance variations can be equivalent to an infinite number of L-C networks. Making resistance variations is much easier than by making reactance variations and one of making resistance variations can be realized by a PDR and a NDR serially coupled with each other. According to the discussion in the background information section a serially coupled PDR and NDR can be a damper. A serially coupled PDR and NDR can generate self-induced frequency elements which can modulate together to generate very broad frequency responses. Any device having PDR and NDR properties will have broader frequency responses than that of the device without PDR and NDR properties.
b has shown the structure of a typical tunnel diode in which a heavily doped p-n junction 703 is formed by coupling a p-type 701 with a n-type 702. The p-n junction formed by the p-type and n-type of a tunnel diode can be called as tunneling junction in the present invention. A tunnel diode can be expressed as a diode having tunneling effect in the present invention. The present invention is not limited to any particular structure and design constructing a tunneling junction of tunnel diode, in other words, the present invention includes all the possible structures and designs constructing tunneling junction of tunnel diode.
A field tunnel diode shown in
A field applied to the field tunnel diode generates the variation of the diode's resistance (PDR and NDR) which can change the voltage level for the tunneling happening resulting in increasing the chances for generating tunneling, and the produced PDR, NDR and tunneling junction will couple and modulate together to generate more frequency elements so that the field tunnel diode will present self-excited multi-band waveforms while a typical tunnel diode presents only single-band waveform, which means that a field applied to the field tunnel diode can be frequency-modulated (FM) by and coupled into the field tunnel diode so that the field tunnel diode can also be viewed as a field-interacted device. The coupling PDR and NDR of the field tunnel diode can generate self-induced frequency elements which can modulate together to generate very broad frequency responses, which makes the field tunnel diode a broadband tunnel diode.
The concepts of multi-band waveforms and single-band waveform are respectively demonstrated in the spectrums of
The field tunnel diode can be a solarcell device shown in
The field tunnel diode can be a light sensor such as charged-coupled device (CCD) or a Hall device which has been shown in
The characteristic of field tunnel diode and tunnel diode have shown that the resistance can be varied between very large number, which can be viewed as “off” state, and zero, which can be viewed as “on” state, so that they can be viewed as a self-excited switch. Field tunnel diode is a passive device which can not be actively controlled. A field tunnel transistor has been invented for being an active device such as a controllable switch, and it has amplification function and broader bandwidth than that of the field tunnel diode.
a has shown a field tunnel transistor 90 in the structure of p-n-p or n-p-n type as a typical transistor.
The field tunnel transistor 90 of
Among the first 901, second 902 and third 903 devices includes at least a PDR and a NDR coupled in series. For example, the arrangement of the first 901, second 902 and third 903 can be an arrangement of PDR-PDR-NDR, PDR-NDR-PDR, PDR-NDR-NDR, NDR-PDR-NDR, NDR-NDR-PDR or NDR-PDR-PDR in which the PDR-NDR-PDR and NDR-PDR-NDR are the better choices for both the two tunneling junctions 904, 905 are formed with a PDR and a NDR. All the possible arrangements are listed in the embodiment of
The first 904 and second 905 tunneling junctions can be any structure of the first and second tunnel diodes respectively formed by the first 901 and second 902 devices and the second 902 and third 903 devices, in other words, the present invention is not limited to any particular structure of the tunneling junction constructing the tunnel diode. As earlier revelation the PDR and NDR can be generated by fields interaction in which the field can be temperature field T, magnetic field such as magnetic flux intensity B, optical field such as optical field intensity I, electric field such as voltage v, current i, frequency f or electrical power P, acoustic field, or mechanical field such as magnitude of force F, and so on, or, any combinations of them. The fields mentioned above applied to the field tunnel transistor can be thru contacting or non-contacting way depending on the types of the field.
The frequency responses of the two tunneling junctions 904, 905 are very possibly different and the two tunneling junctions with the fields interacteded PDR and NDR will couple and modulate together to violently generate more frequency elements than that of the field tunnel diode so that the bandwidth and waveforms of the field tunnel transistor 90 are even broader and more complicated than that of a field tunnel diode 70.
The field tunnel transistor 90 shown in
The field tunnel transistor shown in
The PDR and NDR of the field tunnel transistor 90 of
Another embodiment, the PDR and NDR of the field tunnel transistor can be interacted by a plurality of fields at the same time, which means that the plurality of the fields can be coupled into the field tunnel transistor at the same time. As stated earlier, the PDR and NDR of the field tunnel transistor can be generated by fields interaction in which the field can be temperature field T, magnetic field such as magnetic flux intensity B, optical field such as optical field intensity I, electric field such as voltage v, current i, frequency f or electrical power P, acoustic field, or mechanical field such as magnitude of force F, and so on, or, any combinations of them. One of the embodiment, the field can be applied on the field tunnel transistor transversely to the current direction.
The field tunnel transistor can be used as an active switch which has been shown in
To control precisional “on” and “off” switchings is the goal pursued by any switch, which is more difficult and important in the high power and high frequency applications. The switch used in the high power condition requires bigger junction area which sets a speed and precisional limits, for example, once a switch is on and it can't be off on time, which can harm the circuit.
One of the main reason to the problem arises from that the frequency of the baseband is not as high as the frequency responses of the p-n junction, in other words, the baseband is not at the same or near level of the frequency response of the p-n junction so that the p-n junction has very big chances to miss the “off” from baseband. The frequency responses of the self-excited carriers carried on the baseband can have very big chances to match the frequency response of the p-n junction so that the precise “on” and “off” can be obtained. The existence of the very broad and complicated carrier carried on the baseband will relief the speed limit on the baseband in a certain degree so that a higher frequency and more reliable switch can be realized. Furthermore, the self-excited carriers carried on the baseband have very big chances to match the frequency response of parasitic capacitances in the p-n junction, which has been known as Miller effect, and cancel the Miller effect to minimize the noises.
A light-emitting diode (LED) is a semiconductor diode that emits light when an electric current is applied in the forward direction of the device. The effect is a form of electroluminescence where incoherent and narrow-spectrum light is emitted from the p-n junction. Like a normal diode, the LED consists of a chip of semiconducting material impregnated, or doped, with impurities to create a p-n junction. The structure of a typical LED can be simply expressed in
A new light-emitting device can be obtained by slightly modifying the field tunnel transistor 90 of
An embodiment of the light-emitting device 11 has been shown in
For example, the frequency response of tunneling junction is usually at the level of x-band (about 1010) which is a lot lower than the level at 1014 of light-emitting frequency of the LED p-n junction. One way to solve the problem is to modulate in another frequency elements which will multiply the frequency response of tunneling junction reaching the frequency level for the LED p-n junction to emitting light.
The NDR or/and PDR of the light-emitting device shown in
One of the important advantage of the inventive light-emitting device is that it can use any existed and mature LED technology. And, the very broad and coherence induced spectrum spreadings make the inventive light-emitting device output richer and softer optical spectrum than that of a traditional LED device and its output is in the form of power not in the resistant type any more.
A field capacitor 1200 with controllable capacitance has been shown in
The capacitor 1200 might need terminals for coupling outside circuits in which a first 1204 and a second 1205 terminals respectively couple the first 1201 and second 1202 electrodes and a third terminal 1206 couples the dielectric 1003.
The selection of a dielectric is one of the key element contributed to the capacitance of the capacitor. Some dielectrics such as ferroelectric and ferromagnetic materials will polarize if they are respectively under the application of electrical and magnetic fields.
The changing of the polarization generates the changing of the capacitance of the capacitor 1200. And, the PDR and NDR can be interacted by fields applied it, which also get involved in the changing of the capacitance of capacitor 1200. Furthermore, the serially coupling of the PDR and NDR functions as damper which will generate more frequency elements to make the capacitor 1200 a very broadband capacitor. And, the changing of the polarization generates the changing of frequency responses that produces the damping effect resulting in the frequency shifting.
A circuit shown in
The present invention has proved that the capacitance of the capacitor can be actively controlled by external fields which can be temperature field T, magnetic field such as magnetic flux intensity B, optical field such as optical field intensity I, electric field such as voltage v, current i, frequency f or electrical power P, acoustic field, or mechanical field such as magnitude of force F, and so on, or, any combinations of them listed above. The PDR and NDR are fields-interacted devices and the coupling of the PDR and NDR has dampering effect which can effectively broaden the frequency response of the capacitor 1200 and make the capacitor 1200 a broadband capacitor.
The field applied to the capacitor 1200 can be thru contacting or non-contacting way depending on the types of the field. For example, an electrical field is applied thru the third terminal 1206 to the capacitor 1200 in the embodiment of
The present invention is not limited to any particular dielectric, for example, the dielectric can be constructed by ferroelectric or ferromagnetic material. The dielectric can be interacted by fields so that it can also be called field-interacted dielectric in the present invention.