Antenna pattern generator and switching apparatus

• US 3,922,685 A
• Filed: 11/20/1974
• Issued: 11/25/1975
• Est. Priority Date: 07/30/1973
• Status: Expired due to Term

• Current Assignee: George F. Opas
• Original Assignee: George F. Opas
• Inventors: Opas, George F.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/525,543
• Time in Patent Office: 370 Days
• Field of Search: 343/853,854,876 333/7D,31R
• US Class Current: 342/372
• CPC Class Codes: H01Q 3/34 by electrical means active lenses or reflecting arrays H01Q3/46

Abstract

A variable pattern antenna system including a plurality of radiating elements, a switching circuit for selectively applying signals to various ones of the radiating elements, a phase shifting circuit for shifting the phase of the signals applied to the elements, and a control circuit for operating the switching circuit and phase shifting circuit to cause variable phase signals to be applied to predetermined radiating elements for changing the pattern of the antenna, and a drive wave-shaping circuit to prevent abrupt switching and the spectrum spreading interference commonly known as '"'"''"'"''"'"''"'"'splatter'"'"''"'"''"'"''"'"' that would occur.

Claims

1. An antenna system used with a radio transmitter for creating a periodic sequence of individually distinct radiation patterns including in combination:

a power splitting circuit having a common terminal for connection to said radio transmitter apparatus and first and second splitting terminals;

a switching circuit having first and second signal terminals, a control terminal, and a plurality of antenna terminals, said switching circuit being responsive to signals applied to said control terminal for selectively connecting, in a predetermined manner with a gradual transition, one of said antenna terminals to said first signal terminal and another of said antenna terminals to said second signal terminal, said first signal terminal being coupled to said first splitting terminal;

a variable phase shifting circuit having first and second terminals and a control terminal, said phase shifting circuit having a predetermined phase shift between said first and second terminals and being responsive to signals applied to said control terminal for periodically changing, in a predetermined manner with a gradual transition, said phase shift between said first and second terminals, said first terminal being coupled to said second splitting terminal and said second terminal being coupled to said second signal terminal;

a plurality of radiating elements, each being connected to one of said antenna terminals of said switching circuit; and

a control circuit developing control signals for creating a periodic sequence of radiation patterns and being connected to said control terminal of said switching circuit and said control terminal of said variable phase shiftting circuit, said switching circuit being responsive to said control signals for selectively connecting, in a predetermined manner with a gradual transition, one of said radiating elements to said power splitting circuit and another of said radiating elements to said phase shifting circuit, said gradual transitions of said switching circuit and said variable phase shifting circuit resulting in small amplitudes for the undesired frequencies created by the periodic changes of said switching circuit and said phase shifting circuit.

2. An antenna system as recited in claim 1 wherein;

said switching circuit includes PIN diodes for selectively connecting said radiating elements to said power splitting circuit and said phase shifting circuit, and said variable phase shifting circuit includes PIN diodes for changing said phase shift.

3. The antenna system as recited in claim 2 which includes;

diode driver means coupled to said PIN diodes for producing a waveform, having gradual changes in amplitude, for biasing said PIN diodes.

4. The antenna system as recited in claim 3 wherein;

said driver means includes square wave generating apparatus and an integrating apparatus coupled to said square wave generating apparatus for developing said waveform having gradual changes in amplitude.

5. An antenna system for use with radio apparatus including in combination:

a power splitting circuit having a common terminal for connection to said radio apparatus and first and second splitting terminals;

a switching circuit having first And second signal terminals and a plurality of antenna terminals, said first signal terminal being coupled to said first splitting terminal;

a variable phase shifting circuit having first and second terminals, and a control terminal, said phase shifting circuit having a predetermined phase shift between said first and second terminals and being responsive to control signals applied to said control terminal for altering said phase shift, said first terminal being coupled to said second splitting terminal and said second terminal being coupled to said second signal terminal, said phase shifting circuit including a quadrature hybrid having an input port, a pair of output ports and an isolated port, said input port being connected to said power switching circuit, and variable impedance means connected to said output ports;

a plurality of radiating elements, each being connected to one of said antenna terminals of said switching circuit; and

a control circuit connected to said switching circuit, said switching circuit being responsive to said control circuit for selectively connecting said radiating elements to said power splitting circuit and said phase shifting circuit in a predetermined manner, said control circuit being further connected to said control terminal of said phase shifting circuit and providing control signals thereto for altering said phase shift in response to said control signals.

6. An antenna system as recited in claim 5 wherein said variable impedance means includes a pair of transmission lines, each line having an end connected to one of said output ports, and means connected to each of said lines for varying the electrical length thereof.

7. An antenna system as recited in claim 6 wherein said length varying means includes a plurality of diodes, each diode being connected to a predetermined point of one of said transmission lines and coupled to said control circuit, each diode being responsive to said control circuit for alternately providing substantially an open circuit load and a short circuit load to one of said transmission lines.

8. An antenna system as recited in claim 7 wherein said switching circuit includes a transmission line and a diode connected thereto, said diode being further coupled to said control circuit and receiving control signals therefrom.

9. An antenna system as recited in claim 8 wherein said splitting circuit includes a 3db coupler.

10. An antenna system as recited in claim 5 wherein each of said radiating elements is one quarter wavelength long, and wherein said radiating elements are spaced one-half wavelength apart.

11. An antenna system as recited in claim 10 including three radiating elements spaced to form an equilateral triangle, each radiating element defining an apex of the triangle.