Varactor tuned coaxial cavity negative resistance diode oscillator

Claim 2

In an electronically tunable solid state oscillator, a reentrant cavity resonator means having a hollow outer conductor and a hollow inner conductor, said inner conductor having a portion projecting reentrantly into the interior of said outer conductor to define a capacitive gap between the inner end of said reentrant portion of said inner conductor and an opposed portion of said resonator, a solid state oscillating element disposed within said capacitive gap of said reentrant cavity resonator in radio frequency energy exchanging relation with the radio frequency electric field of said capacitive gap for exciting said cavity resonator with radio frequency energy at the resonant frequency of said cavity resonator, solid state voltage variable capacitance means connected in series for radio frequency energy with said solid state oscillating element and disposed within said capacitive gap of said resonator, radio frequency choke means disposed within said hollow inner conductor in DC insulative relation with said inner conductor for applying A first bias potential to one end terminal of said series connection of said voltage variable capacitance means and said solid state oscillating element, means for applying a second bias potential to the other end terminal of said series connection of said voltage variable capacitance means and said oscillating element, inductive wire means for applying a ground bias potential to the common terminal intermediate said series connected voltage variable capacitance means and said solid state oscillator element, and said inductive wire means being dimensioned to parallel resonate with the package capacitance of said voltage variable capacitance means at a frequency to substantially tune out said package capacitance within the tunable frequency band of the tunable solid state oscillator.

Claim 3

The apparatus of claim 1 including means for varying the bias potential applied across said voltage variable capacitance means for electronically varying the resonant frequency of said reentrant cavity resonator and thus the frequency of radio frequency excitation of said resonator.

Claim 4

The apparatus of claim 1 wherein said solid state oscillating element is a bulk effect negative resistance diode.

Claim 5

The apparatus of claim 1 wherein said variable capacitance means is a voltage variable capacitance diode.

Claim 6

The apparatus of claim 1 wherein said inductive wire means connects said common terminal and said inner conductor, and means for establishing a DC ground bias potential on said inner conductor.

Claim 7

The apparatus of claim 1 wherein said inductive wire is connected at one end to said common terminal and at the other end to the inner end of said reentrant inner conductor.

Claim 8

In an electronically tunable solid state oscillator, a reentrant cavity resonator means having a hollow outer conductor and a hollow inner conductor, said inner conductor having a portion projecting reentrantly into the interior of said outer conductor to define a capacitive gap between the inner end of said reentrant portion of said inner conductor and an opposed portion of said resonator, a solid state oscillating element disposed within said capacitive gap of said reentrant cavity resonator in radio frequency energy exchanging relation with the radio frequency electric field of said capacitive gap for exciting said cavity resonator with radio frequency energy at the resonant frequency of said cavity resonator, solid state voltage variable capacitance means connected in series for radio frequency energy with said solid state oscillating element and disposed within said capacitive gap of said resonator, radio frequency choke means disposed within said hollow inner conductor in DC insulative relation with said inner conductor for applying a first bias potential to one end terminal of said series connection of said voltage variable capacitance means and said solid state oscillating element, means for applying a second bias potential to the other end terminal of said series connection of said voltage variable capacitance means and said oscillating element, inductive wire means for applying a ground bias potential to the common terminal intermediate said series connected voltage variable capacitance means and said solid state oscillator element. Second solid state electrically variable capacitance means disposed within said reentrant cavity resonator and outside of said capacitive gap in shunt with said solid state oscillating element, and means for applying a bias potential across said second variable capacitance means.

Claim 9

In an electronically tunable solid state oscillator, a reentrant cavity resonator means having a hollow outer conductor and a hollow inner conductor, said inner conductor having a portion projecting reentrantly into the interior of said outer conductor to define a capacitive gap between the inner end of said reentrant portion of said inner conductor and an opposed portion of said resonator, a solid state oscillating element disposed within said capacitive gap of said reentrant cavity resonator in radio frequency energy exchanging relation with the radio frequency electric field of said capacitive gap for exciting said cavity resonator with radio frequency energy at the resonant frequency of said cavity resonator, solid state voltage variable capacitance means connected in series for radio frequency energy with said solid state oscillating element and disposed within said capacitive gap of said resonator, radio frequency choke means disposed within said hollow inner conductor in DC insulative relation with said inner conductor for applying a first bias potential to one end terminal of said series connection of said voltage variable capacitance means and said solid state oscillating element, means for applying a second bias potential to the other end terminal of said series connection of said voltage variable capacitance means and said oscillating element, inductive wire means for applying a ground bias potential to the common terminal intermediate said series connected voltage variable capacitance means and said solid state oscillator element. Second solid state electrically variable capacitance means disposed within said reentrant cavity resonator and outside of said capacitive gap in shunt with said solid state oscillating element, and means for applying a bias potential across said second variable capacitance means.

Claim 10

The apparatus of claim 7 wherein said means for applying a bias potential across said second variable capacitance means includes; second hollow conductor means having a bore intersecting with the hollow interior of said outer conductor of said cavity resonator, second radio frequency choke means disposed within said bore in DC insulative relation with respect to said second hollow conductor, said second variable capacitance means having first and second terminals, said first terMinal of said second capacitance means being connected electrically to said second choke means, and second inductive wire means connecting said second hollow conductor and said second terminal of said second variable capacitance means.