Network-fed phased array antenna system with intrinsic RF phase shift capability
First Claim
1. An integral antenna element and RF phase shifter particularly for use as a controllable element in a phase scanned array fed from an RF transmission line of a type selected from a group including waveguide and stripline, said transmission line having longitudinal conductive outer walls through which RF energy may be coupled by means of slots, comprising:
- means including a pair of slot patterns through one of said outer walls, the slots of said patterns being placed symmetrically about the longitudinal centerline of said one outer wall, each of said slot patterns thereby capable of providing coupling on both sides of said longitudinal centerline of said outer wall;
and means including at least four RF devices each of a type capable of providing a controlled RF admittance path for providing admittance ranging at least between discrete minimum and maximum values as a function of a corresponding control signal applied thereto, at least two of said RF devices being placed to control corresonding admittance paths within one of said slot patterns with one of said RF devices on each side of said longitudinal centerline of said outer wall.
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Abstract
An integral element/phase shifter for use in a phase scanned array. A non-resonant waveguide or stripline type transmission line, series force feeds the elements of an array. In the embodiments shown, four RF diodes are arranged in connection within the slots of a symmetrical slot pattern in the outer conductive wall of the transmission line to vary the coupling therefrom through the slots to the aperture of each individual antenna element. Each diode thus controls the contribution of energy from each of the slots (at a corresponding phase) to the individual element aperture and therefore determines the net phase of the said aperture. Three species of the invention are shown, the first and second involving RF diodes in the slots of waveguide broad and narrow walls respectively, and the third having slots through the shield plane of a stripline. The invention facilitates array phase scanning without the need for separate, and relatively more expensive, discrete phase shifters for each antenna element.
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Citations
16 Claims
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1. An integral antenna element and RF phase shifter particularly for use as a controllable element in a phase scanned array fed from an RF transmission line of a type selected from a group including waveguide and stripline, said transmission line having longitudinal conductive outer walls through which RF energy may be coupled by means of slots, comprising:
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means including a pair of slot patterns through one of said outer walls, the slots of said patterns being placed symmetrically about the longitudinal centerline of said one outer wall, each of said slot patterns thereby capable of providing coupling on both sides of said longitudinal centerline of said outer wall; and means including at least four RF devices each of a type capable of providing a controlled RF admittance path for providing admittance ranging at least between discrete minimum and maximum values as a function of a corresponding control signal applied thereto, at least two of said RF devices being placed to control corresonding admittance paths within one of said slot patterns with one of said RF devices on each side of said longitudinal centerline of said outer wall. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a phase-scanned array including a plurality of radiating elements series force-fed from a non-resonant RF transmission line of a type selected from the general group including waveguide and stripline having a conductive outer wall;
- apparatus operatively associated with each of said elements for varying the phase RF energy at a corresponding element aperture comprising;
a plurality of slots in a predetermined pattern through said outer wall of said transmission line, said slots being arranged to couple energy therethrough in at least four discrete relative phases to said element aperture formed adjacent to said slot pattern, to provide a summed signal at said element aperture; means comprising at least one RF diode across each of said slots, said diodes each providing a conductive RF path in response to the forward biasing condition of a corresponding applied control signal and substantially no RF conduction in response to the reverse biasing condition of said control signal; and means for programming the application of said control signals to at least some of said diodes thereby to control the net phase of said summed signal. - View Dependent Claims (14, 15, 16)
- apparatus operatively associated with each of said elements for varying the phase RF energy at a corresponding element aperture comprising;
Specification