Meteorological device employing a temperature compensated transmitter

Claim 2

A rocketsonde, used for measuring atmospheric conditions having a highly stable oscillator, said oscillator comprising: dual cavities for maintaining oscillator resonance, said dual cavities being constructed of a material having a coefficient of thermal expansiOn and being closely juxtaposed so as to be in electrical contact; center conductors mounted inside each of said cavities and fabricated of a material having a different coefficient of thermal expansion than said dual cavities; adjusting means for changing the resonant frequency of said cavities and for maintaining said oscillator at substantially the same frequency as the rocketsonde is subjected to various atmospheric conditions when said center conductors and said cavities expand and contract at unequal rates; power supply means connected to said oscillator, and; output means coupled to one of said dual cavities for transmitting to a remote station.

Claim 3

The rocketsonde oscillator according to claim 1, and further comprising: a transistor mounted on said dual cavities, said transistor having an emitter, collector, and base lead; said power supply means is connected so as to negatively bias said emitter; means for capacitively coupling said emitter to said one of said center conductors; means for capacitively coupling the base of said transistor to the other of said center conductors; said output means is coupled to the cavity containing said base, and; means for grounding said collector to said cavities.

Claim 4

The rocketsonde oscillator according to claim 2, and further comprising: said means for negatively biasing said emitter comprises a current limiting resistor connected in series with a feedthrough capacitor in a cavity wall and an RF choke mounted inside said cavity containing said emitter; means for connecting said cavities and said base through a resistor in series with a feedthrough capacitor in a cavity wall and an RF choke mounted inside said cavity containing said emitter, and; current leveling means connected between said means for connecting and said negative biasing means.

Claim 5

The rocketsonde oscillator according to claim 3, and further comprising: said current leveling means comprises a series-connected resistor and silicon diode.

Claim 6

A highly stable oscillator comprising: dual resonant cavities fabricated of a material having one coefficient of thermal expansion; center conductors mounted in each of said dual cavities and fabricated of a material having a second coefficient of thermal expansion thereby providing capacitance changes between said center conductors and said cavities as said center conductors and said cavities unequally expand and contract when subjected to temperature changes, and a transistor oscillator circuit connected to said cavities in such a manner that said transistor base is capacitively coupled to one of said dual resonant cavities, said transistor emitter is capacitively coupled to the other of said dual resonant cavities and to a negative power source, and said transistor collector is grounded to said dual resonant cavities thereby producing a highly stable transistor oscillator.

Claim 7

A highly stable oscillator comprising: dual resonant cavities fabricated of a material having one coefficient of thermal expansion; center conductors mounted in each of said dual cavities and fabricated of a material having a second coefficient of thermal expansion thereby providing capacitance changes between said center conductors and said cavities as said center conductors and said cavities unequally expand and contract when subjected to temperature changes, and a transistor oscillator circuit connected to said cavities in such a manner that said transistor base is capacitively coupled to one of said dual resonant cavities, said transistor emitter is capacitively coupled to the other of said dual resonant cavities and to a negative power source, and said transistor collector is grounded to said dual resonant cavities thereby producing a highly stable transistor oscillator.

Claim 10

The resonant deviCe according to claim 6 and further comprising: sets of adjusting screws mounted in the ends of each cavity and in the walls of each cavity adjacent to the second ends of said center conductors for distributing the capacitance required for resonance between the second end of said center conductors and the ends of said cavities and between the second end of said center conductors and said cavity walls thereby giving said oscillator an essentially flat frequency versus temperature characteristic.

Claim 11

A dual coaxial transistor oscillator that is highly stable over a wide range of environmental conditions comprising: a pair of cylindrically shaped cavities each having walls, enclosed ends, and a longitudinal axis, said cavities being constructed of a material having a first coefficient of thermal expansion, said cavities being placed adjacent to each other and in electrical contact; center conductors having first and second ends mounted inside said dual cavities with said first end in electrical contact with said cavity ends and parallel to the longitudinal axis thereof, said center conductor being fabricated of a material having a second coefficient of thermal expansion so that the capacitance between said cavities and said center conductors is divided between said cavity ends and said second end of said center conductors and between said cavity walls and said second end of said center conductors as said center conductors and said cavities unequally expand and contract as said device is subjected to varying environmental conditions; a transistor mounted on said cavities and having a base, emitter, and collector; said base being capacitively coupled to one of said center conductors and to the wall of one of said cavities; said emitter being negatively biased and capacitively coupled to the other of said center conductors; said collector being connected to the wall of one of said cavities, thereby providing oscillations within said cavities; at least one adjusting screw mounted in the wall of one of said cavities thereby providing frequency adjustment means and providing said oscillator with an essentially flat oscillating frequency versus temperature characteristics over a wide range range of environmental conditions.

Claim 12

A dual coaxial transistor oscillator that is highly stable over a wide range of environmental conditions comprising: a pair of cylindrically shaped cavities each having walls, enclosed ends, and a longitudinal axis, said cavities being constructed of a material having a first coefficient of thermal expansion, said cavities being placed adjacent to each other and in electrical contact; center conductors having first and second ends mounted inside said dual cavities with said first end in electrical contact with said cavity ends and parallel to the longitudinal axis thereof, said center conductor being fabricated of a material having a second coefficient of thermal expansion so that the capacitance between said cavities and said center conductors is divided between said cavity ends and said second end of said center conductors and between said cavity walls and said second end of said center conductors as said center conductors and said cavities unequally expand and contract as said device is subjected to varying environmental conditions; a transistor mounted on said cavities and having a base, emitter, and collector; said base being capacitively coupled to one of said center conductors and to the wall of one of said cavities; said emitter being negatively biased and capacitively coupled to the other of said center conductors; said collector being connected to the wall of one of said cavities, thereby providing oscillations within said cavities; at least one adjusting screw mounted in the wall of one of said cavities thereby providing frequency adjustment means and providing said oscillator with an essentially flat oscillating frequency versus temperature characteristics over a wide range range of environmental conditions.

Claim 13

The device according to claim 8, and further comprising: coupling means attached to one of said cavities for transmitting said oscillations to a remote station.