High speed PIN diode switched antenna coupler and method

• US 4,502,025 A
• Filed: 04/23/1982
• Issued: 02/26/1985
• Est. Priority Date: 04/23/1982
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Pedtke, Daniel F., Koontz, Floyd, Carl, Robert H. Jr.
• Primary Examiner(s): Gensler, Paul
• Application Number:
  US06/371,247
• Time in Patent Office: 1,040 Days
• Field of Search: 333/17 M, 333/24 R, 333/177, 333/185, 334/56, 334/71, 334/38, 336/195, 455/120, 455/125
• US Class Current: 333/24.00R
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance

Abstract

A high speed antenna coupler and method for rapidly switching binary weighted values of inductance and capacitance into and out of the circuit between an antenna and a utilization circuit without unacceptably degrading the coupler or slowing the switching action. PIN diodes are utilized as switches and the control wires for the PIN diodes are disposed interiorly of the copper tubing which forms the inductance elements. The control wire for a particular inductor is withdrawn from the interior of that inductor adjacent the mid-point thereof so that the control wire will be at the same RF potential as the inductor being controlled. Two diodes are utilized for each inductor, one connected to each end thereof, so that only half of the normal reverse bias is required for switching purposes. Where a transformer is utilized to couple the antenna to the utilization circuit, the control wires may be disposed interiorly of the copper tubing which forms the winding of the transformer. A novel high voltage drive circuit is also disclosed.

Claims

1. A high speed antenna coupler for electrically coupling an antenna to a utilization circuit comprising:

a plurality of inductors each having an axial passageway and wound to a predetermined value of inductance, each of said inductors being apertured adjacent the mid-length thereof;

a plurality of PIN diodes each having an anode connected to one end of one of said plurality of inductors, the cathodes of the two diodes connected to each of said inductors being interconnected,

a driver circuit for each of said plurality of inductors;

a plurality of control wires each connected between one of said plurality of driver circuits and one of said interconnections,

each of said control wires passing through the axial passageway of those of said plurality of inductors intermediate the one of said plurality of driver circuits and the one of said plurality of inductors to which connected, and each passing through the aperture in the one of said plurality of inductors to which connected; and

means for selectively operating said plurality of driver circuits to thereby selectively switch said plurality of inductors into and out of the circuit between an antenna and a utilization circuit by the biasing of the two diodes associated therewith.

2. The coupler of claim 1 wherein said inductors are uninsulated metallic tubing and wherein said control wires are electrically insulated conductors.

3. The coupler of claim 2 wherein said plurality of inductors are series connected;

and

including a plurality of capacitors each having first and second diodes associated therewith,

the anode of said first diode being connected to one end of the one of said plurality of inductors furthest from the antenna,

the cathode of said first diode being connected to the anode of said second diode and to one side of said capacitor, and

the cathode of said second diode being connected by one of said control wires to one of said plurality of driver circuits whereby said driver circuit may selectively couple said capacitor into and out of the circuit between said series connected inductors and the utilization circuit.

4. The coupler of claim 3 including a transformer for coupling the antenna to the utilization circuit;

wherein one winding transformer has an axial passageway; and

wherein said plurality of control wires pass through the axial passageway in said winding.

5. The coupler of claim 4 wherein each of said plurality of driver circuits includes:

means for providing first and second temporally spaced signals in response to an instruction signal;

an output terminal;

a source of positive potential;

a second source of negative potential; and

switch means responsive to said first and second signals for alternatively (a) disconnecting said first source from said output terminal and for thereafter connnecting said second source to said output terminal and (b) disconnecting said second source from said output terminal and for thereafter connecting said first source to said output terminal.

6. The coupler of claim 1 wherein said inductors are connected in parallel;

and

including a plurality of series connected capacitors,

two PIN diodes for each of said capacitors, said diodes having an anode connected to opposite sides of the associated one of said capacitors and interconnected cathodes connected by one of said control wires to one of said driver circuits so that said driver circuits may selectively couple said capacitor into and out of the coupler by the biasing thereof.

7. The coupler of claim 1 including a transformer for coupling the antenna to the utilization circuit;

wherein a winding of said transformer has an axial passageway; and

wherein said plurality of control wires pass through said axial passageway.

8. The coupler of claim 7 wherein said transformer is an autotransformer having a single tapped winding of metallic tubing.

9. The coupler of claim 1 wherein each of said plurality of driver circuits includes:

means for providing first and second temporally spaced signals in response to an instruction signal;

an output terminal;

a source of positive potential;

a second source of negative potential; and

switch means responsive to said first and second signals for alternatively (a) disconnecting said first source from said output terminal and for thereafter connnecting said second source to said output terminal and (b) disconnecting said second source from said output terminal and for thereafter connecting said first source to said output terminal.

10. In a method of rapidly switching impedance elements into and out of the circuit between an antenna and a utilization device by the application of digital control signals from a driver circuit to one or more PIN diodes associated therewith without unacceptable degrading of the circuit or slowing the switching action, the improvement comprising the step of passing a bias control signal for the PIN diodes coaxially through tubular inductive impedance elements intermediate the driver circuit and the element being switched.

11. In a method of rapidly switching impedance elements into and out of the circuit between an antenna and a utilization device by the application of digital control signals from a driver circuit to one or more PIN diodes associated therewith without unacceptable degrading of the circuit or slowing the switching action, the improvement comprising the step of passing a bias control signal for the PIN diodes coaxially through any inductive impedance elements intermediate the driver circuit and the element being switched,

wherein the impedance element being switched is a tubular inductor, and wherein the PIN diodes associated therewith are two in number each connected to one end of the inductor and to each other;

and

including the further step of applying the bias controlling signal to the interconnection of the two diodes.

12. The improvement of claim 11 wherein the control signal is applied to the interconnection of the two diodes from the approximate mid-point of the inductor.

13. The improvement of claim 11 wherein the antenna is coupled to a utilization circuit through an autotransformer, and

including the further step of passing the bias controlling signals coaxially through the inductor of the autotransformer.

14. A method of fabricating an inductor for an antenna coupler comprising the steps of:

(a) providing a length of electrically conductive tubing having an aperature adjacent the mid-point thereof;

(b) passing a plurality of electrically insulated conductors axially through the tubing and withdrawing one of the conductors through the aperture;

(c) forming the tubing into an inductor coil without removing the conductors;

(d) electrically connecting two diodes to each other and to opposite ends of the inductor; and

(e) electrically connecting the withdrawn conductor to the interconnection of the diodes.