Circuit assembly with conical inductor

1. A circuit assembly, comprising:

a substrate having a slot,

a conical inductor disposed in the slot,

a conductor of a high frequency transmission line, a lead from a narrow end of the conical inductor being electrically connected to the conductor, and

a package suspending the substrate and providing a ground plane acting in cooperation with the conductor to form a microstrip transmission line.

2. The circuit assembly of claim 1 further comprising a recess in the package at least below the conical inductor.

3. The circuit assembly of claim 2 wherein the recess is set back a selected distance from an edge of the conductor to maintain a characteristic impedance of the microstrip transmission line.

4. A circuit assembly, comprising:

a substrate having a slot; and

a conical inductor partially disposed in the slot,

wherein the substrate is characterized by a top surface within which the slot is formed,

and the conical inductor has a wide end characterized by a diameter, and the maximum vertical height of the conical inductor above the top surface is less than the diameter;

further comprising a ground plane on a backside of the substrate,

wherein a portion of the ground plane is removed from the backside of the substrate to form a cleared portion underneath at least the conical inductor.

5. The circuit assembly of claim 4 further comprising:

a first conductor of a high frequency transmission line on the top surface of the substrate, a lead from a narrow end of the conical inductor being electrically connected to the conductor;

wherein the wide end of the conical inductor extends below the backside of the substrate.

6. A circuit assembly, comprising:

a substrate having a slot; a conical inductor having a narrow end and a wide end; and

the conical inductor partially disposed in the slot;

wherein the slot has a back wall in direct contact with the wide end of the conical inductor.

7. A circuit assembly, comprising:

a substrate having a slot; and

a conical inductor partially disposed in the slot,

wherein the inductor comprises a conical coil having a narrow end and a wide end, and

wherein the slot includes a back wall and a cut-out portion, and the back wall is in direct contact with the wide end of the conical coil.

8. The circuit assembly of claim 4 wherein the conical inductor is secured to the substrate with adhesive.

9. The circuit assembly of claim 4 wherein the conical inductor cooperates with the slot so as to position a narrow end of the conical inductor with respect to a conductor of a high-frequency transmission line.

10. The circuit assembly of claim 6 wherein the back wall cooperates with the wide end of the conical inductor to determine a position of the wide end with respect to a conductor of a high-frequency transmission line.

11. The circuit assembly of claim 4 wherein a narrow end of the conical inductor is raised above the top surface of the substrate.

12. The circuit assembly of claim 4 , further comprising:

a conductor of a high frequency transmission line on the top surface of the substrate, and

a lead from a narrow end of the conical inductor being electrically connected to the conductor.

13. The circuit assembly of claim 4 , further comprising:

a first conductor on the top surface of the substrate,

wherein the ground plane cooperates with the first conductor to form a high frequency transmission line.