HYBRID SCAN ANTENNA

• US 3,864,689 A
• Filed: 08/02/1973
• Issued: 02/04/1975
• Est. Priority Date: 08/02/1973
• Status: Expired due to Term

• Current Assignee: GEC Astronics Corporation
• Original Assignee: David W. Young
• Inventors: Young, David W.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/385,085
• Time in Patent Office: 551 Days
• Field of Search: 343/1SA,768,771,854,705
• US Class Current: 342/372
• CPC Class Codes: H01Q 3/34 by electrical means active lenses or reflecting arrays H01Q3/46

Abstract

A hybrid antenna system comprises two or more wave guide antenna sections which are physically separated and separately fed with radiant energy from a single source by dividing up energy from the source and feeding it into first ends of the various sections. Phase shifters are provided such that the radiant energy fed to successive sections is shifted in phase in such a manner that the overall radiated output beam from all of these sections constitutes a single beam which may be scanned in the same manner as though all of the sections were connected together to form a single elongated wave guide antenna. The provision of the antenna in sections makes it more convenient to locate the antennas on various portions of an aircraft to realize the same effect as an elongated single waveguide type antenna.

Claims

1. A hybrid scan antenna comprising, in combination:

a. at least two physically separated elongated wave guide antenna sections;

b. coupler means for receiving electromagnetic energy from a single source and dividing it to feed equal amounts to said antenna sections;

c. mechanical means for scanning radiant energy emitted by each of said antennas, said scanning being sychronized;

d. phase shift means exterior of the antenna sections including means positioned to receive the energy fed to one of said sections and shift its phase relative to the energy fed to the other of said sections; and

, e. control means connected to said phase shift means and responsive to the scanned position of radiant energy emitted by the antennas to cause the phase shift means to shift the phase of the energy fed to said one antenna in a manner such that said radiant energy is in the form of a single beam which is scanned the same as though the sections were connected end to end to form a single long continuous wave guide antenna, said phase shift means shifting the phase of energy received thereby in a continuous manner as a linear function of a varying input signal, said control means including means for deriving said varying input signal for the phase shift means from said mechanical means for scanning radiant energy.

2. An antenna according to claim 1, in which said phase shift means includes a plus-minus feedback controlled phase shifter, a plus phase shifter, a minus phase shifter, and a feedback phase detector, said plus-minus feedback controlled phase shifter receiving radiant energy fed to one of said sections and passing it through said plus phase shifter, the output from said plus shifter passing to the first end of said one antenna section, said minus phase shifter receiving energy from the other end of said one section and shifting its phase in a manner opposite to the phase shift by said plus phase shifter to provide energy to one side of said feedback phase detector so that said energy is in phase with the phase of the energy supplied from said plus-minus feedback controlled phase shifter, radiant energy from the other end of the other of said antenna sections passing to the other side of said feedback phase detector, said feedback phase detector providing an output error signal proportional to any phase difference of the energy received in its sides to said plus-minus feedback controlled phase shifter to effect a correction in the phase of the energy passed to said plus phase shifter in a manner to reduce the error signal towards zero, said control means connecting to both said plus and minus phase shifters to simultaneously control the phase shifts thereof which take place in opposite directions, in accordance with the scan position of the radiant energy emitted by the antEnnas.

3. An antenna according to claim 1, in which said phase shift means comprises a digital type phase shifter for shifting the phase of energy fed thereto in discrete steps in response to an input signal, said control means comprising a phase detector having its sides connected to receive radiant energy fed to said first ends and providing said input signal to said phase shifter whenever the difference in phase of said energy reaches a predetermined amount.