Superconducting apparatus for converting microwaves into work

A superconducting microwave engine that achieves mechanical to microwave rgy conversion or microwave to mechanical energy conversion. Such is accomplished by employing a superconducting resonator to increase the decay time of the microwaves inside the resonator and thereby provide the resonator with sufficient time to adiabatically deform and change its eigenfrequency so as to effect a change in the frequency and corresponding energy state of such microwaves in accordance with the Boltzmann-Ehrenfest Theorm. This invention may be in the form of a cylindrical cavity and piston combination, a cavity and vibrating diaphragm combination, or a cylindrical cavity and concentric rotor combination.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an engine and more particularly to a 
superconducting microwave engine. 
2. Description of the Prior Art 
The prior art consists essentially of scientific principles and theorms 
which heretofore defied operational application because of difficulties 
encountered in structuring a design which could overcome the physical 
constraints inherent in such principles and theorms. The most significant 
area of difficulty lay in constructing a resonator (or deformable cavity) 
in which the frequencies of the microwaves contained therein could be 
changed without significant energy loss or decay. 
The present invention applies the principles of superconductivity to the 
design and construction of a resonator to appreciably increase the decay 
time of the microwaves contained therein and thereby overcome the 
aforementioned difficulties and make the efficient operation of a 
microwave engine feasible. 
SUMMARY OF THE INVENTION 
The invention is an engine that converts work into high frequency 
microwaves or, conversely, high frequency microwaves into work. This is 
accomplished through the use of a cavity with deformable walls, or 
resonator, which has superconducting porperties. That is, by using special 
materials and keeping the walls at an extraordinarily low temperature, the 
walls' internal resistance is substantially reduced and, concomitantly, 
the microwaves inside the cavity are not absorbed by the walls upon impact 
as quickly as would normally be the case. Consequently, their decay time 
is significantly increased enabling the cavity to be deformed from a shape 
corresponding to one specific eigenfrequency to another before significant 
dissipation of the microwave energy through absorbtion by the walls has 
occured. High frequency microwaves are generated by the compression of 
such a superconducting cavity containing low frequency microwaves into a 
high eigenfrequency shape by mechanical work, and are subsequently coupled 
out of the cavity at an appropriate point in the cycle. Work is generated 
by the expansion of cavity walls caused by the injection of high frequency 
microwaves into such a superconducting cavity when it is in a compressed, 
high eigenfrequency shape. 
The various physical forms the invention may take correspond essentially to 
different means for effecting a rapid cyclic deformation of the cavity 
from one shape to another and, completing the cycle, back to the original 
shape. Those combinations set out herein are examples of such means. 
STATEMENT OF THE OBJECTS OF THE INVENTION 
An object of the present invention is to use a superconducting resonator to 
convert low frequency microwaves into a larger amount of microwave energy 
at a higher frequency. 
Another object of the present invention is to use a superconducting 
resonator to generate work through the conversion of high frequency 
microwave energy into a lesser amount at a lower frequency. 
A further object of the present invention is to provide an efficient method 
of energy transmission. 
Other objects, advantages and novel features of the invention will become 
apparent from the following detailed description of the invention when 
considered in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
It is well known that magnetic fields cause forces, the pressure produced 
by a magnetic field B being given by the expression (B.sup.2 / 
2.mu..sub.o.) Oscillating magnetic fields are also known to cause forces 
of the same type. Assuming that the radiation of a magnetic field were 
contained in an ideal resonator (a deformable cavity) with perfectly 
flexible walls, a counter balancing force on the walls of the same 
magnitude would be required to preserve equilibrium. However, if the 
external force on the walls of such an ideal resonator was increased 
slightly the volume of the resonator would contract and mechanical work 
would be done on the electromagnetic fields contained therein. This work 
would cause an increase in the stored electromagnetic energy. 
The particular form taken by the energy in such a resonator is described by 
the Boltzman-Ehrenfest Theorem. This theorem states that if the 
deformation is slow enough only one mode will continue to be excited, and 
the energy contained in that mode will be given by the equation E = Nhw(X) 
where N = the number of photons in the cavity, h = h/2 and h is the Planck 
constant, and w(X) = the instantaneous eigenfrequency of the cavity 
deformed in some manner with X being the parameter of deformation. 
If the time for decay of the microwave energy into heat in the walls of the 
cavity is much longer than the time required for the deformation of the 
cavity, it is possible to inject energy into the cavity at one frequency 
and, after deformation, extract a different amount of energy at a 
different frequency, that is, the eigenfrequency corresponding to the 
latter configuration of the cavity. If the final frequency is higher than 
the original frequency injected into the cavity, the engine will have 
generated energy in microwave form. The difference between the microwave 
energy originally injected and the final state of microwave energy will be 
the mechanical work performed by the walls of the cavity against the 
radiation pressure of the electromagnetic fields inside the cavity 
required to deform the cavity and thereby change its eigenfrequency. 
Where the final frequency is lower than the initial frequency, then the 
engine will have generated mechanical power. The difference between the 
input and output energies will be work performed by radiation pressure of 
the electromagnetic fields in deforming the cavity walls. 
For practical operation, the engine of the present invention will operate 
cyclically, that is, (1) the injections of microwaves of a relatively low 
frequency, (2) the deformation of the cavity through the application of 
work, (3) the transfer of the microwaves of the resultant higher frequency 
out of the cavity, and (4) the deformation of the cavity back to its 
original configuration. This constitutes one complete cycle for the mode 
of operation to generate microwave energy from work. To generate work from 
high frequency microwave energy, the operative cycle consists of (1) the 
injection of microwaves of a relatively high frequency, (2) the 
deformation of the cavity caused by the radiation pressure of the 
electromagnetic fields and the derivation of useful work from such 
deformation, (3) the exhaust of microwaves of the resultant lower 
frequency from the cavity, and (4) the deformation of the cavity back to 
its original configuration. 
In order to effectively function, two conditions must be met: (1) the 
frequency of the cyclic cavity deformation must be low relative to the 
electromagnetic frequency, .gamma.; and (2) since any real resonator or 
cavity has losses, the electromagnetic energy must not decay significantly 
into heat during the time required for the deformation, that is, one-half 
of the time required to complete a mechanical cycle. 
The first condition is that the cavity deformation must be adiabatic, that 
is, the time required for deformation must be longer than the time for one 
microwave cycle, 1/.gamma.. For mechanical frequencies currently 
attainable it is impossible to violate this condition. 
The second condition is that the microwave energy must not dissipate 
significantly during the time required for mechanical deformation of the 
cavity. With any normal material this is an impossible requirement, but 
through the application of the principles of superconductivity to the 
design and construction of a resonator this condition may be satisfied, 
and such application forms the basis for the operational feasibility of 
the present invention. 
Referring to FIG. 1, engine 10 is an embodiment of the present invention in 
the form of a cylindrical cavity and piston combination. Engine 10 
includes deformable cylindrical cavity 13, walls 14, piston 15, rod 17, 
crankshaft 19, low frequency (w(X.sub.1)) microwave source 21, valve 22, 
port 23, high frequency (w(X.sub.2)) microwave load 25, valve 26, port 27, 
and microwaves 29. 
Piston 15 slides within the cavity formed by walls 14. Both walls 14 and 
piston 15 are superconducting. Deformable cylindrical cavity 13 is formed 
by walls 14 and the left face of piston 15. Rod 17 is rotatably attached 
to piston 15 at one end, and rotatably attached to crankshaft 19 at its 
other end. Port 23 communicates between low frequency microwave source 21 
and cavity 13. Valve 22 is located within port 23, and low frequency 
microwave source 21 communicates with cavity 13 by means of port 23 only 
when valve 22 is open. Port 27 communicates between high frequency 
microwave load 25 and cavity 13. Valve 26 is located within port 27, and 
high frequency microwave load 25 communicates with cavity 13 by means of 
port 27 only when valve 26 is open. Ports 23 and 27 may be any means known 
in the art to transfer microwaves efficiently from one volume into 
another, e.g., a connecting wave guide or a connecting waveguide with a 
co-axial rod physically penetrating cavity 13. 
FIG. 1A is a graph schematically showing the position of piston 15 and the 
energy transfer through port 23 and port 27 with respect to time during 
the mechanical cycle for engine 10 operating in the mode to generate high 
frequency microwaves (w(X.sub.2)) from work and input low frequency 
(w(X.sub.1)) microwaves. FIG. 1B is a graph schematically showing the 
position of piston 15 and the energy transfer through port 23 and port 27 
with respect to time during the mechanical cycle for engine 10 operating 
to generate useful work from input high frequency (w(X.sub.2)) microwaves 
(the rectification mode of operation). 
Referring to the FIGS. 1, 1A, and 1B, when piston 15 is in position X.sub.1 
cavity 13 achieves its maximum volume and is in a shape with an 
eigenfrequency of w(X.sub.1). While piston 15 is in position X.sub.1, port 
23 is opened by means of valve 22 to allow the passage of microwaves of 
low frequency w(X.sub.1) from source 21 into cavity 13 and thereby excite 
the cavity with microwave energy E.sub.1 at frequency w(X.sub.1). Port 23 
is then closed by means of valve 22 and, as port 27 remains closed during 
this interval, cavity 13 is effectively sealed. A driving means (not 
shown) applies mechanical work to crankshaft 19 to cause it to rotate 
counterclockwise at mechanical frequency .OMEGA.. This work is 
subsequently applied by means of rod 17 to piston 15 to force it to move 
to the viewer's left and thereby change the configuration of cavity 13. 
Such translational movement continues until position X.sub.2 is realized, 
at which point cavity 13 achieves its minimum volume and has an 
eigenfrequency of w(X.sub.2). The change in configuration causes 
microwaves 29 to undergo an increase in frequency to w(X.sub.2) in 
accordance with the Boltzmann-Ehrenfest Theorem, and consequently 
generates a proportional increase in microwave energy stored in cavity 13 
to E.sub.2, where 
##EQU1## 
While in position X.sub.2 port 27 is opened by means of valve 26 and 
microwaves 29 at high frequency w(X.sub.2) are thereby transmitted out of 
cavity 13 and applied to high frequency microwave load 25. After such 
evacuation of cavity 13, port 27 is closed by means of valve 26 (port 23 
remains closed during the aforementioned interval) and piston 15 is 
returned by crankshaft 19 to position X.sub.1 to complete the engine 
cycle. In practice, the cycle is rapidly repeated. 
Engine 10 may also be used to generate useful work from input high 
frequency microwaves. In this mode of operation, low frequency microwave 
source 21 is instead a source of high frequency (w(X.sub.2)) microwaves, 
high frequency microwave load 25 is instead a low frequency (w(X.sub.1)) 
microwave exhaust sink, and the driving means connected to crankshaft 19 
is instead a load (not shown). The cycle is begun with piston 15 at 
position X.sub.2. Port 23 is opened by means of valve 22 to allow cavity 
13 to become excited with microwave energy E.sub.2 at frequency w(X.sub.2) 
from source 21 and subsequently closed to seal the cavity as port 27 
remains closed throughout this interval. The radiation pressure of 
microwaves 29 upon the left pg,10 face of piston 15 forces the piston to 
undergo translation to position X.sub.1. This translational movement 
causes the clockwise rotation of crankshaft 19, thereby generating useful 
mechanical work for application to a connected load (not shown). 
When piston 15 reaches position X.sub.1, the frequency of microwaves 29 is 
at lowered value w(X.sub.1) as a result of the change in the configuration 
of cavity 13 in accordance with the Boltzman-Ehrenfest Theorm. While 
piston 15 is at X.sub.1, port 27 is opened by means of valve 26 and 
microwaves 29 of frequency w(X.sub.1) are exhausted into low frequency 
microwave exhaust sink 25. Port 27 is subsequently closed by means of 
valve 26, and, to complete the cycle, piston 15 is returned to initial 
position X.sub.2 by the continued rotational motion of crankshaft 19 
applied to piston 15 by rod 17. In operation, the cycle is rapidly 
repeated. 
FIGS. 2 and 2A show top and front sectional views, respectively, of engine 
30, an embodiment of the present invention in the form of a cavity and 
vibrating diaphragm combination. Engine 30 includes low frequency (w(A)) 
microwave source 33, fixed configuration cavity 35 having low 
eigenfrequency w(A), fixed configuration cavity 43 having high 
eigenfrequency w(B), deformable configuration cavity 39 having a variable 
eigenfrequency which ranges between w(A) and w(B), and high frequency 
(w(B)) microwave load 35. Diaphragm 47 comprises one wall of deformable 
cavity 39. Coupling port 34 cmmunicates between low frequency microwave 
source 33 and fixed configuration cavity 35. Coupling port 37 communicates 
between fixed configuration cavity 35 and deformable configuration cavity 
39. Coupling port 41 communicates between deformable configuration cavity 
39 and fixed configuration cavity 43. Coupling port 44 communicates 
between fixed configuration cavity 43 and high frequency microwave load 
35. Cavities 35, 39, and 43, and coupling ports 37 and 41 are all 
superconducting. 
Diaphragm 47 is connected by any means to mechanical drive 45. Diaphragm 47 
is free to flex between two extreme positions, position A and position B, 
and is driven to vibrate between the aforementioned positions at a 
frequency of .OMEGA. cycles/second by mechanical drive 45. When diaphragm 
47 is in position A, deformable configuration cavity 39 has an 
eigenfrequency of w(A); when diaphragm 47 is in position B, cavity 39 has 
an eigenfrequency of w(B), where w(B) &gt; w(A). 
FIG. 2B is a graph schematically showing the position of diaphragm 47 and 
the energy transfer through each of ports 34, 37, 41, and 44 with respect 
to time during the mechanical cycle for engine 30 operating in the mode to 
generate high frequency (w(B)) microwaves from work and input low 
frequency (w(A)) microwaves. FIG. 2C is a graph showing the position of 
diaphragm 47 and the energy transfer through each of ports 34, 37, 41, and 
44 with respect to time during the mechanical cycle for engine 30 
operating to generate useful work from input high frequency (w(B)) 
microwaves (the rectification mode of operation). 
To initiate the mode of operation whereby engine 30 generates high 
frequency microwaves from low frequency microwaves and work, source 33 
excites cavity 35 with low level microwave energy at correspondingly low 
frequency w(A) by means of coupling port 34. Coupling port 34 remains 
physically open throughout the operational cycle of engine 30 in order to 
allow source 33 to continually excite cavity 35 with microwave energy of 
low frequency w(A). 
The electromagnetic coupling of microwaves between two cavities becomes 
very strong when their respective eigenfrequencies approach equality. 
Thus, the low frequency microwaves in cavity 35 will couple into 
deformable configuration cavity 39 through coupling port 37 whenever 
cavity 39 deforms into a configuration having an eigenfrequency virtually 
equal to that of fixed cavity 35, that is, W(A). This will occur whenever 
diaphragm 47 is in position A. Therefore, no means are necessary to 
alternatively close and open port 37. 
The microwaves remain in cavity 39, but are excited to a higher energy 
level at a correspondingly higher frequency, w(B), in accordance with the 
Boltzmann-Ehrenfest Theorm by the movement of diaphragm 47 to position B, 
said movement being accomplished against the radiation pressure of the 
microwaves contained in cavity 39 by means of work applied by mechanical 
drive 45. An electromagnetic drive may be substituted for the mechanical 
drive illustrated in FIG. 2A without loss of effectiveness. 
Upon reaching the higher exitation state corresponding to the configuration 
of cavity 39 associated with diaphragm position B, the microwaves are 
transferred out of cavity 39 by means of the mechanism of electromagnetic 
coupling through coupling port 41 to excite cavity 43. This coupling 
mechanism will operate through coupling port 41 whenever cavity 39 is 
excited with microwaves of frequency w(B); that is, whenever diaphragm 47 
is in position B. No means are necessary to alternatively close and open 
port 41. The high energy microwaves of frequency w(B) are subsequently 
coupled from cavity 43 by means of coupling port 44 and applied to high 
frequency microwave load 35. Coupling port 44 remains physically open 
throughout the operative cycle of engine 30. Microwaves of frequency w(B) 
will be coupled through coupling port 44 continuously throughout the 
operative cycle of engine 30, as shown in FIG. 2B, although the 
quantitative amount of energy transferred from cavity 43 to load 35 during 
any discrete interval will vary. 
After the high frequency microwaves have been coupled out of cavity 39, the 
cycle is completed by the return of diaphragm 47 to its initial position A 
by means of mechanical drive 45. In practice, the cycle described herein 
is rapidly repeated, e.g., 2000 mechanical cycles per second. 
To employ engine 30 to produce mechanical work from high frequency 
microwaves, load 35 must instead be high frequency (w(B)) microwave source 
35; low frequency microwave source 33 must instead be low frequency (w(A)) 
microwave exhaust sink 33; and mechanical drive 45 must instead be work 
load 45. 
Assuming the foregoing changes, the cycle is initiated by the excitation of 
cavity 43 by microwaves of frequency w(B) from source 35 by means of port 
44. Cavity 43 is continually excited at such frequency by such means. Such 
microwaves are then coupled into cavity 39 by means of coupling port 41 
when cavity 39 has an eigenfrequency of w(B); that is, when cavity 39 is 
in the configuration associated with diaphragm position B. The radiation 
pressure of the high energy microwaves at their correspondingly high 
frequency, w(B), forces diaphragm 47 to move to position A, and work is 
thereby generated for application to work load 45. 
The movement of the diaphragm towards position A causes the frequency and 
energy level of the microwaves in cavity 39 to decrease in accordance with 
the Boltzmann-Ehrenfest Theorm. When position A is reached the microwaves 
are excited at frequency w(A) and are coupled through coupling port 37 out 
of cavity 39 to excite cavity 35. The microwaves in cavity 35 are coupled 
through coupling port 34 into low frequency microwave exhaust sink 33 
continuously throughout the operative cycle. Diaphragm 47 is subsequently 
returned to initial position B to complete the cycle. In practice, the 
cycle described herein is rapidly repeated. 
Referring to the sectional views shown in FIGS. 3 and 3A, engine 50 is an 
embodiment of the present invention in the form of a cylindrical cavity 
and concentric rotor combination (turbine). Engine 50 includes low 
frequency (w(A)) microwave source 51, fixed configuration cavity 55 having 
low eigenfrequency w(A), fixed configuration cavity 65 having high 
eigenfrequency w(B), deformable configuration cavity 59 having a variable 
eigenfrequency which ranges between w(A) and w(B), and high frequency 
(w(B)) microwave load 69. Concentric rotor 61 is located within deformable 
configuration cavity 59, and its outer surface forms one wall of the 
cavity. Coupling port 53 communicates between low frequency microwave 
source 51 and fixed configuration cavity 55. Coupling port 57 communicates 
between fixed configuration cavity 55 and deformable configuration cavity 
59. Coupling port 63 communicate between deformable configuration cavity 
59 and fixed configuration cavity 65. Coupling port 67 communicates 
between fixed configuration cavity 65 and high frequency microwave load 
69. Cavities 55, 59, and 65, and coupling ports 57 and 63 are all 
superconducting. 
Cavity 59 is comprised of six smaller enclaves. This number is used for 
illustrative purposes. In practice, this embodiment of the invention may 
have any number of nodes and enclaves greater than one. Regardless of the 
number of enclaves, the configuration and eigenfrequency of the respective 
enclaves will be mutually identical at every point in the mechanical cycle 
of engine 50, that is, for every angular position of rotor 61. Regardless 
of the number of enclaves, only one port for the transfer of low frequency 
microwaves into the resonator and one to effect the transfer of high 
frequency microwaves out of the resonator, e.g., ports 57 and 63, 
respectively, are necessary because of the high strength of the coupling 
between the respective enclaves. 
Concentric rotor 61 rotates freely about an axis lying along the axis of 
symmetry of cavity 59. Concentric rotor 61 is rotated in a clockwise 
direction at a frequency of .OMEGA. revolutions/second by a driving means 
(not shown). When concentric rotor 61 is in position A, each and every one 
of the respective enclaves of cavity 59 has an eigenfrequency of w(A); 
when rotor 61 is in position B, each and every one of the aforementioned 
enclaves has an eigenfrequency of w(B), where w(B)&gt; w(A). 
FIG. 3b shows a graph indicating the position of rotor 61 (left vertical 
axis) and the corresponding angular orientation, .theta., of rotor 61 with 
respect to the datum shown in FIG. 3 (right vertical axis), with both of 
the foregoing parameters being displayed as a function of time (horizontal 
axis) during the operation of engine 50 in the mode to generate high 
frequency (w(B)) microwaves from work and low frequency (w(A)) microwaves. 
Directly below this graph is a related graph showing whether energy is 
being transferred through each of coupling ports 53, 57, 63, and 67 for 
each point in time on the aforementioned graph of rotor position and 
.theta. versus time. 
FIG. 3C shows two related graphs illustrating the operational 
interrelationships of the same parameters in the same manner as set out in 
FIG. 3B for the operation of engine 50 in the mode to generate useful work 
from input high frequency (w(B)) microwaves (the rectification mode of 
operation). 
To operate engine 50 to produce high frequency microwaves from low 
frequency microwaves and work, cavity 55 is excited with low frequency 
microwave energy E.sub.A at frequency w(A) from source 51 by means of 
coupling through coupling port 53. Cavity 55 remains excited with such 
energy by such means continually during the operation of the engine. 
With rotor 61 initially in position A and .theta.= 0 (see FIG. 3), each and 
every one of the enclaves of cavity 59 is in a configuration having an 
eigenfrequency of w(A), and the mechanism of electromagnetic coupling 
operates to transfer microwaves of frequency w(A) from cavity 55 into the 
enclaves of cavity 59 through coupling port 57. Such transfer by means of 
coupling will operate through port 57 whenever rotor 61 is in position A. 
No means are necessary to alternatively open and close port 57. 
Rotor 61 is subsequently rotated clockwise to position B (.theta. = .pi./6; 
see FIG. 3A), increasing the enclaves' eigenfrequency to w(B). The 
"compression" resulting from this rotation is resisted by reactive 
electromagnetic forces generated by the microwaves contained in cavity 59, 
and such forces are overcome by the application of work to rotor 61 by any 
appropriate means (not shown). In accordance with the Boltzmann-Ehrenfest 
Theorm, the change in the enclaves' eigenfrequency caused by the rotation 
of rotor 61 from position A to position B causes an increase in the level 
of microwave energy contained in the enclaves to E.sub.B at the 
correspondingly increased frequency w(B), where 
##EQU2## 
While rotor 61 is in position B the high frequency (w(B)) microwave energy 
contained in cavity 59 is transferred into cavity 65 by means of 
electromagnetic coupling through coupling port 63. Such transfer will 
occur whenever cavity 59 is excited with microwaves of frequency w(B). No 
means are necessary to alternatively open and close port 63. 
The high frequency microwaves are subsequently applied to microwave load 69 
by means of coupling from cavity 65 through port 67. As shown in FIG. 3B, 
microwaves of frequency w(B) are continuously coupled through coupling 
port 67 throughout the operative cycle of engine 50, although the 
quantitative amount of energy transferred during any discrete interval 
will vary. 
After the microwaves of energy E.sub.B have been coupled into cavity 65 
from cavity 59, the operative cycle is completed by the continued 
clockwise rotation of rotor 61 back into starting position A 
(.theta.=.pi./3). In practice, the cycle is repeated very rapidly. 
In order to use engine 50 to produce work from high frequency microwaves, 
high frequency microwave load 69 must instead be high frequency (w(B)) 
microwave source 69, low frequency microwave source 51 must instead be low 
frequency (w(A)) microwave exhaust sink 51, and the means for the 
application of work (not shown) to rotor 61 must instead be a work load 
connected to rotor 61 by any appropriate means (not shown). 
To start the engine, microwaves of high energy E.sub.B at frequency w(B) 
from source 69 are coupled into cavity 65 by means of coupling port 67. As 
shown in FIG. 3C, cavity 65 remains excited with such energy by such means 
continually during the operation of the engine. 
With rotor 61 initially in position B and .theta.=.pi./6, the cavity 
configuration of maximum eigenfrequency w(B), the microwave energy from 
cavity 65 is coupled into cavity 59 by means of coupling port 63. The 
electromagnetic fields generated by the microwaves contained in the 
enclaves of cavity 59 exert radiation pressure against rotor 61 and force 
it to rotate clockwise to a position corresponding to a lower enclave 
eigenfrequency, position A (.theta.=.pi./3). Any appropriate mechanical 
means may be used to derive the work done by the electromagnetic fields in 
rotating rotor 61. The change in the shape of cavity 59 from that 
associated with position B to that associated with position A results in a 
lowering of the energy level of the microwaves contained therein from 
E.sub.B to E.sub.A and a corresponding decrease in frequency from w(B) to 
w(A) in accordance with the Boltzmann-Ehrenfest Theorm. 
When rotor 61 is in position A the microwaves in cavity 59, now at lowered 
energy level E.sub.A at corresponding lower frequency w(A), are coupled 
out of cavity 61 to excite cavity 55 by means of coupling port 57. The 
microwaves are subsequently coupled out of cavity 55 into exhaust sink 51 
by means of coupling port 53. The rotation of rotor 61 is continued until 
position B is again achieved (.theta.=.pi./2), thereby completing the 
cycle. In practice, the cycle is rapidly repeated. 
The ratio between the eigenfrequencies of the resonator at the extremes of 
deformation, that is, w(B)/w(A), where 
##EQU3## 
is known as the compression ratio. There is an upper limit on the 
compression ratio and, therefore, the microwave energy output, E.sub.B, 
attainable with the design illustrated in FIGS. 3 and 3A due to the 
breakdown of superconductivity that will occur when the critical magnetic 
field is exceeded as well as the constraint associated with the limiting 
electric field. As the compression ratio is increased, the operative limit 
will be approached as relatively large magnetic and electrical fields will 
be generated by the radical change in configuration of the cavity required 
to attain the desired compression ratio. 
This problem may be overcome by cascading several states of this design (as 
in conventional turbine design) to achieve further compression and 
appropriately increase the level of output microwave energy. For example, 
engine 50 could be cascaded by substituting a deformable configuration 
cavity of the design of deformable configuration cavity 59 in place of 
high frequency microwave load 69. The microwaves of energy E.sub.B would 
be coupled into this second deformable configuration cavity through 
coupling port 67, where their energy level and corresponding frequency 
would be increased by a compression cycle identical to that described 
hereinbefore for deformable configuration cavity 59. The microwaves 
excited at this increased frequency would then be coupled into a fixed 
configuration cavity of a matching eigenfrequency, and subsequently 
coupled to a high frequency microwave load. 
It should be noted that the above described one step cascade could be 
repeated any number of times to achieve virtually any desired high 
frequency microwave output. 
Similarly, one or more deformable configuration cavities operating in the 
rectification mode and communicating with fixed configuration cavities of 
appropriately matched eigenfrequencies could be connected in series to 
engine 50 operating in the rectification mode to increase the useful work 
derivable from input microwave energy before the exhaust of such 
microwaves to an exhaust sink. 
It is to be understood that although the technique of cascading is 
explained in reference to the cylindrical cavity and concentric rotor 
combination embodiment of the present invention, the technique is not 
limited in applicability to this particular embodiment. Cascading may be 
used with any embodiment of the present invention to increase the maximum 
obtainable output frequency or, in the rectification mode, to increase the 
maximum amount of useful work derivable from an amount of input high 
frequency microwave energy. 
An elevational cross section of a detailed design of an embodiment of the 
present invention in the form of the cylindrical cavity and concentric 
rotor combination is illustrated in FIG. 4. FIG. 4A is a horizontal cross 
section taken along lines 4A--4A of FIG. 4. Engine 70 is basically the 
turbine design shown in FIGS. 3 and 3A with two enclaves instead of six. 
Engine 70 includes outer casing 117, inner casing 115, and cavity block 
113. Outer casing 117 contains inner casing 115 and cavity block 113. 
Inner casing 115 contains cavity block 113. Vacuum space 116 is the volume 
within outer casing 117 surrounding inner casing 115. Volume 114 is the 
volume within inner casing 115 surrounding cavity block 113. 
Cavity block 113 includes fixed configuration cavity 73 having low 
eigenfrequency w(A), fixed configuration cavity 77 having high 
eigenfrequency w(B), deformable configuration cavity 75 having a variable 
eigenfrequency ranging between w(A) and w(B), coupling port 74, and 
coupling port 76. Coupling port 74 communicates between fixed 
configuration cavity 73 and deformable configuration cavity 75. Coupling 
port 76 communicates between deformable configuration cavity 75 and fixed 
configuration cavity 77. 
Rotor 79 is positioned within deformable configuration cavity 75, and has a 
superconducting outer surface which forms one wall of cavity 75. Rotor 79 
is free to rotate about an axis lying along the axis of symmetry of cavity 
75. Rotor 79 is driven to rotate clockwise about this axis at a frequency 
of .OMEGA. revolutions/second by a driving means (not shown) connected to 
rotor drive belt 111. The rotor assembly also includes insulating support 
105, rotating seal 107, and support bearing 109. Rotor 79 has a hollow 
center filled with liquid helium 100 for the purpose of keeping the outer 
surface of rotor 79 at a temperature low enough to maintain its 
superconductive properties. Gaseous helium exhaust line 91 communicates 
between liquid helium 100 and vacuum pump 92 in order to vent gaseous 
helium boiled off of the liquid helium 100 by heat generated by the 
operation of engine 70. Another purpose is to maintain a pressure upon 
liquid helium 100 below the ambient value, and thereby keep helium 100 at 
a proportionally cooler temperature. Vacuum insulated transfer tube 95 
communicates between liquid helium source 98 and liquid helium 100 to 
allow for the replacement of liquid helium 100 which is boiled off by heat 
generated from the operation of engine 70 with liquid helium from liquid 
helium source 98. 
Volume 114 is almost filled with liquid helium 99 to immerse cavity block 
113 in liquid helium 99. Cavity block 113 is immersed in liquid helium 99 
for the purpose of keeping the surfaces of cavities 73, 75, and 77 and 
coupling ports 74 and 76 contained within cavity block 113 at temperatures 
low enough to maintain their superconductive properties. Gaseous helium 
exhaust line 93 communicates between volume 114 and vacuum pump 94 in 
order to vent gaseous helium boiled off of liquid helium 99 by heat 
generated by the operation of engine 70. A second purpose is to maintain a 
pressure upon liquid helium 99 below the ambient value, and thereby keep 
helium 99 at a proportionally cooler temperature. Vacuum insulated 
transfer tube 97 communicates between volume 114 and liquid helium source 
98 in order to allow for the replacement of liquid helium 99 boiled off by 
heat generated from the operation of engine 70 with liquid helium from 
liquid source 98. 
Vacuum space 116 is kept at a vacuum by means of communication (not shown) 
with a vacuum pump (not shown). The purpose of maintaining this vacuum is 
to prevent any gas from entering deformable configuration cavity 75 where 
the presence of such gas would result in sparking and also increase the 
frictional force opposing the rotation of rotor 79. 
Engine 70 also includes low frequency (w(A)) microwave source 83, waveguide 
84, vacuum window 85, high frequency (w(B)) microwave load 88, waveguide 
86, vacuum window 87, and microwaves 112. Waveguide 84 communicates 
between low frequency microwave source 83 and fixed configuration cavity 
73. Waveguide 86 communicates between fixed configuration cavity 77 and 
high frequency microwave load 88. 
Vacuum window 85 is positioned in waveguide 84. Vacuum window 87 is 
positioned in waveguide 86. Both vacuum windows 85 and 87 are permeable to 
microwaves but not to air. Their purpose is to prevent the leakage of air 
into the cavities contained in cavity block 113 because such air would 
condense upon the superconducting surfaces due to their low temperatures 
(approximately -268.degree. C). 
FIG. 4B shows a graph indicating the position of rotor 79 (left vertical 
axis) and the corresponding angular orientation, .theta., of rotor 79 with 
respect to the datum shown in FIG. 4A (right vertical axis), with both of 
the foregoing parameters being displayed as a function of time (horizontal 
axis) during the operation of engine 70 in the mode to generate high 
frequency (w(B)) microwaves from work and low frequency (w(A)) microwaves. 
Directly below this graph is a related graph showing whether energy is 
being transferred through each of coupling ports 74 and 76 and waveguides 
84 and 86 for each point in time on the aforementioned graph of rotor 
position and .theta. versus time. 
FIG. 4C shows two related graphs illustrating the operational 
interrelationships of the same parameters in the same manner as set out in 
FIG. 4B for the operation of engine 70 in the mode to generate useful work 
from input high frequency (w(B)) microwaves (the rectification mode of 
operation). 
To generate high frequency microwaves energy fron engine 70, cavity 73 is 
excited with low frequency microwaves of energy E.sub.A at frequency w(A) 
from source 83 by means of waveguide 84. Cavity 73 is continuously 
maintained in this state of excitation by such means during the operation 
of the engine. 
With rotor 79 initially in position A and .theta.=0, both of the enclaves 
are in a configuration which has an eigenfrequency of w(A), and microwave 
energy E.sub.A at frequency w(A) is transferred from cavity 73 into cavity 
75 by means of electromagnetic coupling through coupling port 74. This 
electromagnetic coupling mechanism will operate through port 74 whenever 
rotor 79 is in position A. No means are necessary to alternatively close 
and open port 74. The high inherent coupling strength between the two 
enclaves of cavity 75 is sufficient to ensure adequate dissemination of 
the microwave energy throughout the cavity; thus, separate input and 
exhaust ports for each enclave are unnecessary. 
Rotor 79 is subsequently rotated to position B (.theta.=.pi./2). The 
configuration of each of the enclaves when rotor 79 is in position B has 
an eigenfrequency of w(B). This clockwise rotation is opposed by reactive 
electromagnetic forces generated by the microwaves contained in cavity 75, 
and work is applied to drive belt 111 by a driving means (not shown) in 
order to overcome this opposing force and achieve the aforementioned 
rotation. In accordance with the Boltzmann-Ehrenfest Theorm, the change in 
the configuration of each of the enclaves, that is, the compression, 
brought about by the rotation of rotor 79 from position A to position B 
causes the enclaves to become excited with a higher level of microwave 
energy E.sub.B at the corresponding increased frequency w(B). While in 
position B, the microwaves of frequency w(B) are transferred into cavity 
77 by means of electromagnetic coupling through coupling port 76. This 
electromagnetic coupling mechanism will operate through port 76 whenever 
cavity 75 is excited with microwave energy at w(B), that is, whenever 
rotor 79 is in position B. No means are necessary to alternatively close 
and open port 76. 
The microwaves of frequency w(B) in cavity 77 are subsequently transferred 
from cavity 77 and applied to microwave load 88 by means of coupling 
through waveguide 86. As shown in FIG. 4B, microwaves of frequency w(B) 
are continuously coupled through waveguide 86 throughout the operative 
cycle of engine 70, although the quantitative amount of energy transferred 
from cavity 77 to load 88 during any discrete interval will vary. Rotor 79 
is rotated clockwise back into starting position A (.theta.=.pi.) to 
complete the cycle. In practice, the cycle described herein is repeated 
very rapidly. 
In order to use engine 70 to generate work from high frequency microwaves, 
load 88 must instead be a source of high frequency (w(B)) microwaves, low 
frequency microwave source 83 must instead be a low frequency microwave 
exhaust sink, and the driving means connected to rotor drive belt 111 must 
instead be an appropriately connected work load (now shown). 
Cavity 77 is first excited with high frequency microwaves of energy E.sub.B 
at frequency w(B) from source 88 by means of coupling through waveguide 
86. Cavity 77 is continuously excited in this state by the aforementioned 
means during the operation of the engine in this mode. 
Rotor 79 starts in position B and .theta.=.pi./2, the position in which 
both of the enclaves in cavity 75 are in a configuration have high 
eigenfrequency w(B). After exciting cavity 77, the microwaves of frequency 
w(B) are transferred into cavity 79 by means of coupling through coupling 
port 76 while the rotor is in position B. The electromagnetic fields 
generated by the microwaves in the enclaves exert radiation pressure 
against rotor 79 and thereby cause it to rotate clockwise to a position 
corresponding to lower enclave eigenfrequency w(A), that is, to position A 
(.theta.=.pi.). The mechanical work performed by the electromagnetic 
fields in forcing this rotation is applied to a load (not shown) connected 
by any mechanical means (not shown) to rotor drive belt 111. In accordance 
with the Boltzmann-Ehrenfest Theorm, the change in the enclave 
configurations, that is, the expansion, brought about by the rotation of 
rotor 79 to position A causes the energy level of the microwaves contained 
in the enclaves of cavity 75 to drop to a lower level E.sub.A at a 
corresponding lower frequency w(A). While in position A, the microwaves in 
cavity 75 are transferred into cavity 73 by means of coupling through 
coupling port 74. 
The microwaves in cavity 73 are subsequently exhausted into sink 83 by 
means of coupling through waveguide 71. The clockwise rotation of rotor 79 
is continued until it is again in position B (.theta.= 3.pi./2), thereby 
completing the cycle. In practice, the cycle is rapidly repeated. 
The operational efficiency of the engine will be a function of the 
microwave energy lost through inelastic collisions between the individual 
photons and the walls of the cavity and thereby rendered unavailable for 
eventual application to an external load. This effect is termed energy 
decay, and is commonly expressed in terms of the amount of time, .tau., a 
cavity will remain excited at a value above a particular percentage of its 
original energy state. Superconducting cavity walls increase the 
elasticity of the photon-wall collisions, and thereby increase the decay 
time. However, the engine will still suffer some degree of loss from decay 
because even superconducting walls possess some resistance and will not 
reflect impacting photons with perfect elasticity. 
The energy loss from decay will occur during the time, T, that the cavity 
is excited with microwave energy. In the cylindrical cavity and piston 
combination embodiment of the present invention shown in FIG. 1, T is the 
interval during which piston 15 is moving from X.sub.1 to X.sub.2 if the 
engine is operating to generate high frequency microwaves. If the engine 
is operating in the rectification mode, T is the interval required for the 
piston 15 to move from X.sub.2 to X.sub.1. Alternatively stated (and 
independent of the operational mode), decay will occur during the time, T, 
required to complete 1/2 of the complete mechanical cycle, or 1/2.OMEGA., 
where .OMEGA. is the mechanical frequency of crankshaft 19 in revolutions 
per unit of time. 
With respect to the cavity and vibrating diaphragm combination embodiment 
of the present invention shown in FIG. 2, T is the interval required for 
diaphragm 47 to move from position A into position B, or, if operating in 
the rectification mode, the time required for diaphragm 47 to move from 
position B into position A. Alternatively stated (and independent of 
operational mode), T = 1/2.OMEGA., where .OMEGA. is the frequency of the 
vibration of diaphragm 47 in cycles per unit of time. 
With respect to the cylindrical cavity and concentric rotor combination 
embodiment of the present invention, T is the time required for the 
concentric rotor to rotate from position A into position B (referring to 
FIGS. 3 and 3A and also to FIGS. 4 and 4A) or, if operating in the 
rectification mode, the interval required for the rotor to rotate from 
position B into position A. Alternatively stated (and independent of the 
operational mode), 
##EQU4## 
where .OMEGA. is the mechanical frequency of the concentric rotor in 
revolutions per unit of time and n is the number of enclaves contained in 
the resonator (or lobes on the concentric rotor). 
Thus, qualitatively speaking, the operational efficiency for each of the 
three embodiments of the present invention disclosed herein is directly 
proportional to the mechanical frequency, .OMEGA., of engine operation. 
However, the analysis also indicates that the cylindrical cavity and 
concentric rotor combination has a unique advantage in that its 
operational efficiency may also be increased by increasing n, the number 
of enclaves contained in the resonator. 
When operating in the region of small energy losses, that is, where 
T/.tau.&lt;&lt;1, the fractional loss of microwave energy due to energy decay 
may be closely approximated by the expression T/.tau.. For each watt of 
energy dissipated into resonator walls, approximately 1,000 watts are 
required for refrigeration to maintain the low temperature of the walls 
necessary for superconductivity. Thus the net engine efficiency .epsilon. 
may be given by the expression 
EQU .epsilon. = 1 - 10.sup.3 T/.tau. (1) 
the decay time .tau. for microwave energy in a resonator with resistive 
losses may be expressed as 
##EQU5## 
(2) where L.sub.1 is a size characteristic of the resonator (the volume 
to surface area ratio), R.sub.s is the surface resistance, and .mu..sub.o 
is the susceptibility of free space to magnetic fields, 
##EQU6## 
The time which the microwaves spend in the resonator, T, is equal to half 
the time required for a mechanical cycle and may also be approximated by 
##EQU7## 
(3) where L.sub.2 is a characteristic size of the resonator and v is the 
velocity with which one part of the resonator moves past another. 
Substituting the expressions for .tau. and T of equations (2) and (3), 
respectively, into equation (1), and setting 
##EQU8## 
an expression for net engine efficiency independent of size may be 
obtained; 
##EQU9## 
(4) 
The basic equation for the power P that may be generated by the engine is 
##EQU10## 
(5) where E is the energy content of the resonator and is given by 
EQU E = (B.sup.2.sub.c/ 2.mu..sub.o) .times. V (6) 
where V is the volume of the resonator and B.sub.c is the limiting magnetic 
field at the superconducting surface in webers/meters.sup.2, that is, the 
maximum magnetic field that may be sustained at the surface of the 
superconducting walls without a breakdown in superconductivity. 
Substituting equations (6) and (3) into equation (5); 
##EQU11## 
(7) Substituting the previous definition for .alpha. gives 
##EQU12## 
(8) where A is the surface area of the resonator. 
Experimental data indicate that R.sub.s, the surface resistance, should lie 
between 10.sup.-.sup.8 .OMEGA. and 10 .sup.-.sup.9 .OMEGA.. A rotor speed, 
v, of 300 meters/second is deemed conservative in view of the current 
state of the turbine art. Based upon cylindrical models, 
.alpha..apprxeq.4. Using the aforementioned parameters and equation (4), 
the net efficiency, .epsilon., of the present invention embodied in the 
turbine form is estimated to lie between 90% and 99% depending on which 
value of surface resistance, R.sub.s, is used. Assuming that an average 
field of 700 gauss could be sustained in the resonator, that is, B.sub.c = 
700 gauss = 0.07 webers/meters.sup.2, the power density as given by 
equation (8) would be approximately 1 .times. 10.sup.5 watts per square 
meter of resonator surface area. The present invention's estimated 
efficiency range is far higher than that currently achievable for either 
microwave generation or the conversion of microwave energy into mechanical 
work. To date, the highest overall efficiency demonstrated by any 
microwave conversion unit is approximately 50%. 
The theoretical equations hereinbefore derived, the performance 
characteristics generated from such equations, and the various parameters 
upon which such characteristics are based are provided solely as an aid to 
the perspective user of the present invention. It is to be understood that 
such equations, performance characteristics, and parameters are not in any 
manner or form intended to define or otherwise restrict the scope or 
boundaries of the present invention. 
Preferably, the present invention should be made out of either solid 
niobium or lead plated copper. Niobium has the highest critical field, but 
lead plated copper is easier to work with and correlates better in 
practice with theoretically predicted fields. Lead is plated onto oxygen 
free high conductivity copper, a type of high purity copper well known in 
the industry, from a fluoborate bath using common commercial techniques. 
FIG. 5 illustrates how two microwave engines may be jointly used to provide 
an efficient method for the transmission of useful work from one location 
to another. 
Microwave engine 1 is operating to generate high frequency microwaves from 
work and input low energy microwaves. The generated high frequency 
microwaves are transmitted through the atmosphere to a receiving antenna 
at a distant location (though waveguides may also be used) where they are 
subsequently fed into microwave engine 2. Engine 2, operating in the 
rectification mode, accepts the high frequency microwaves, exhausts low 
frequency microwaves, and generates work for application to a load near 
the site of the engine. 
Implementation of the invention should permit the transmission of energy in 
microwave form at an overall efficiency substantially higher than that 
currently achievable in the state of the art, at an efficiency comparable 
or superior to that of conventional electronic power transmission 
(especially as the distance separating the points of transmission and 
rectification increase), and to and from locations heretofore difficult if 
not virtually impossible to reach.