Multiple diode coaxial cavity oscillator with manual and varactor diode tuning

Claim 2

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N Diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respect to said inner conductor and said outer conductor to oscillate at a frequency within a given broad frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; and third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; said second means including a broadband DC blocking arrangement formed within said inner conductor adjacent said other end of said inner conductor having a high impedance one-quarter wavelength line disposed adjacent said N diodes and in a longitudinal relation to said inner conductor, a low impedance one-quarter wavelength line spaced from said high impedance line remote from said N diodes and in a longitudinal relation to said inner conductor, and a spacer of electrical insulation disposed in a transverse relation to said inner conductor abutting the end of said low impedance line remote from said high impedance line, said spacer having a diameter equal to the diameter of said inner conductor; and a one-quarter wavelength impedance transformer having a layer of electrical insulation encircling said inner conductor and a metallic annular member encircling said layer, said annular member having an inner surface in sliding contact with the outer surface of said layer and an outer surface in spaced relation with the inner surface of said outer conductor.

Claim 3

An oscillator according to claim 1, wherein each of said N diodes are Gunn diodes.

Claim 4

An oscillator according to claim 1, wherein each of said N diodes are Impatt diodes.

Claim 5

An oscillator according to claim 1, wherein said first means includes a low pass filter coupled to said one end of said inner conductor.

Claim 6

An oscillator according to claim 1, wherein said outer conductor provides a heat sink for said coaxial line cavity.

Claim 7

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respect to said inner conductor and said outer conductor to oscillate at a frequency within a given broad radio frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; and third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; said third means including a capacitive sliding shorting arrangement; said sliding shorting arrangement including a layer of electrical insulation disposed on the outer surface of said inner conductor, a tubular metallic shell disposed in a sliding relation on the outer surface of said layer, a first metallic annular member disposed adjacent one end of and fixed to said shell, the outer surface of said first member slidably engaging the inner surface of said outer conductor, and a second metallic annular member disposed adjacent the other end of and fixed to said shell, the outer surface of said second member slidably engaging the inner surface of said outer conductor, said first and second member being spaced lonitudinally from each other by one-quarter wavelength at the center frequency of said given broad radio frequency range.

Claim 8

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respect to said inner conductor and said outer conductor to oscillate at a frequency within a given broad radio frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; and third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; said third means including a capacitive sliding shorting arrangement; said sliding shorting arrangement including a layer of electrical insulation disposed on the outer surface of said inner conductor, a tubular metallic shell disposed in a sliding relation on the outer surface of said layer, a first metallic annular member disposed adjacent one end of and fixed to said shell, the outer surface of said first member slidably engaging the inner surface of said outer conductor, and a second metallic annular member disposed adjacent the other end of and fixed to said shell, the outer surface of said second member slidably engaging the inner surface of said outer conductor, said first and second member being spaced lonitudinally from each other by one-quarter wavelength at the center frequency of said given broad radio frequency range.

Claim 9

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respet to said inner conductor and said outer conductor to oscillate at a frequency within a given broad radio frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; a varactor diode having an anode and a cathode, at least said cathode extending into said coaxial line cavity in spaced relation with respect to said inner conductor and said outer conductor; a metallic loop disposed within said coaxial line cavity interconnecting said cathode and said outer conductor; and fourth means coupled to said anode to couple a given signal to said varactor to deviate the frequency of said output radio frequency signal.

Claim 10

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respet to said inner conductor and said outer conductor to oscillate at a frequency within a given broad radio frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; a varactor diode having an anode and a cathode, at least said cathode extending into said coaxial line cavity in spaced relation with respect to said inner conductor and said outer conductor; a metallic loop disposed within said coaxial line cavity interconnecting said cathode and said outer conductor; and fourth means coupled to said anode to couple a given signal to said varactor to deviate the frequency of said output radio frequency signal.

Claim 11

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respect to said inner conductor and said outer conductor to oscillate at a frequency within a given broad radio frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; and third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; said first means including a low pass filter coupled to said one end of said inner conductor; said outer conductor providing a heat sink for said coaxial line cavity; said second means including a broadband DC blocking arrangement formed within said inner conductor adjacent said other end of said inner conductor having a high impedance one-quarter wavelength line disposed adjacent said N diodes and in a longitudinal relation to said inner conductor, a low impedance one-quarter wavelength line spaced from said high impedance line remote from said N diodes and in a longitudinal relation to said inner conductor, and a spacer of electrical insulation disposed in a transverse relation to said inner conductor abutting the end of said low impedance line remote from said high impedance line, said spacer having a diameter equal to the diameter of said inner conductor; and a one-quarter wavelength impedance transformer having a first layer of electrical insulation encircling said inner conductor and a metallic annular member encircling said first layer, said annular member having an inner surface in sliding contact with the outer surface of said first layer and an outer surface in spaced relation with the inner surface of said outer conductor; and said third means including a second layer of electrical insulation disposed on the outer surface of said inner conductor, a tubular metallic shell disposed in a sliding relation on the outer surface of said second layer, a first metallic annular member disposed adjacent one end of and fixed to said shell, the outer surface of said first member slidably engaging the inner surface of said outer conductor, and a second metallic annular member disposed adjacent the other end of and fixed to said shell, the outer surface of said second member slidably engaging the inner surface of said outer conductor, said first and second member being spaced longitudinally from each other by one-quarter wavelength at the center frequency of said given broad radio frequency range.

Claim 12

A broadband multiple diode cavity oscillator comprising: a coaxial line cavity having an inner conductor and an outer conductor; N negative resistance diodes, where N is an integer greater than one, each of said N diodes being of the same diode type and directly connected between said inner conductor and said outer conductor with an orientation with respect to said inner conductor and said outer conductor to oscillate at a frequency within a given broad radio frequency range; first means disposed adjacent one end of said inner conductor to couple a DC bias voltage to said inner conductor and, hence, to said N diodes; second means disposed adjacent the other end of said inner conductor to provide an output radio frequency signal having a frequency in said given broad radio frequency range, said output signal resulting from the combined oscillation of each of said N diodes; and third means disposed adjacent said one end of said inner conductor and in a sliding relation between said inner conductor and said outer conductor to tune said coaxial line cavity through said given broad radio frequency range; said first means including a low pass filter coupled to said one end of said inner conductor; said outer conductor providing a heat sink for said coaxial line cavity; said second means including a broadband DC blocking arrangement formed within said inner conductor adjacent said other end of said inner conductor having a high impedance one-quarter wavelength line disposed adjacent said N diodes and in a longitudinal relation to said inner conductor, a low impedance one-quarter wavelength line spaced from said high impedance line remote from said N diodes and in a longitudinal relation to said inner conductor, and a spacer of electrical insulation disposed in a transverse relation to said inner conductor abutting the end of said low impedance line remote from said high impedance line, said spacer having a diameter equal to the diameter of said inner conductor; and a one-quarter wavelength impedance transformer having a first layer of electrical insulation encircling said inner conductor and a metallic annular member encircling said first layer, said annular member having an inner surface in sliding contact with the outer surface of said first layer and an outer surface in spaced relation with the inner surface of said outer conductor; and said third means including a second layer of electrical insulation disposed on the outer surface of said inner conductor, a tubular metallic shell disposed in a sliding relation on the outer surface of said second layer, a first metallic annular member disposed adjacent one end of and fixed to said shell, the outer surface of said first member slidably engaging the inner surface of said outer conductor, and a second metallic annular member disposed adjacent the other end of and fixed to said shell, the outer surface of said second member slidably engaging the inner surface of said outer conductor, said first and second member being spaced longitudinally from each other by one-quarter wavelength at the center frequency of said given broad radio frequency range.

Claim 13

An oscillator according to claim 8, further including a transverse opening through said outer conductor intermediate said second member and said N diodes, a varactor diode having an anode and a cathode, said varactor diode being disposed in said transverse opening so that at least said cathode extends into said coaxial line cavity in spaced relation with respect to said inner conductor and said outer conductor, and a metallic loop disposed within said coaxial line cavity between said second member and said N diodes interconnecting said cathode and said outer conductor, and a conductor coupled to said anode disposed coaxial of said transverse opening to couple a given signal to said varactor to deviate the frequency of said output radio frequency signal.

Claim 14

An oscillator according to claim 9, wherein N is equal to 2.