Dual mode seeker

Patent metadata

Field	Value
Publication number	US-10539396-B1
Application number	US-69208876-A
Country	US
Kind code	B1
Filing date	Jun 2, 1976
Priority date	Jun 2, 1976
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

A dual mode RF/IR seeker suitable for use in an anti-radiation missile is disclosed. The infrared sensor is responsive to radiation within the 4.0 to 4.8 micron band and the radio frequency sensor is responsive to radio frequency signals within a 6.5 to 16.5 GHz band. The infrared sensor comprises a folded Cassegrainian telescope arrangement, including a primary mirror which is transparent to radio frequency energy. The radio frequency sensor comprises an annular array of orthogonally disposed stripline flared notch radiating elements. A broadband microwave receiver, fabricated in a multilayered stripline package, is provided for forming radio frequency monopulse sum′ (E) and difference (A) signals and for converting such radio frequency monopulse signals to suitable intermediate frequency signals for processing in an I.F. receiver.

First claim

What is claimed is:

1. A dual mode seeker for a missile, such seeker being selectively responsive to either infrared or radio frequency energy radiated from a target to produce guidance signals, such seeker comprising:
(a) a gimbal arrangement having two degrees of freedom with respect to the longitudinal axis of said missile;
(b) an optical receiving system, responsive to infrared energy from said target, for deriving first guidance signals for said missile, such optical receiving system including a Cassegrainian telescope having a rear surface primary mirror for directing the infrared energy to a sensor mounted in said gimbal system;
(c) a radio frequency receiving system, responsive to radio frequency energy from said target, for deriving second guidance signals for said missile, such radio frequency receiving system including an antenna mounted in said gimbal arrangement behind said primary mirror and around said sensor whereby the boresight axes of said sensor and said antenna are coincident and a refractive lens disposed between said primary mirror and said antenna, such lens having a shape to collimate radio frequency energy passing through such mirror; and
(d) selection means, responsive to the first and second guidance signals, for determining the particular one of such signals to control the flight of said missile.

2. A dual mode seeker as in claim 1 wherein the antenna comprises an orthogonal array of end-fired stripline antenna elements.

3. A dual mode seeker as in claim 2 wherein orthogonal pairs of the antenna elements are fed, in phase quadrature, from a single feed point.

4. A dual mode seeker as in claim 3 having, additionally:
(a) a radio frequency power divider network coupled to individual ones of said feed ports; and
(b) a radio frequency arithmetic unit connected to said power divider network to form a monopulse receiving arrangement for the radio frequency receiving system.

5. A dual mode seeker as in claim 4 wherein the selection means comprises:
(a) logic circuitry, responsive to the relative amplitudes, with respect to noise, of the infrared signals out of the sensor and the radio frequency signals out of the antenna, for selecting one or the other of the first and the second guidance signals; and
(b) logic circuitry, responsive to predetermined control signals applied before flight of said missile for selecting one or the other of the optical receiving system or the radio frequency receiving system to produce guidance signals during the initial stage of flight of said missile.

6. A dual mode seeker as in claim 5 wherein said optical receiving system and said radio frequency receiving system share a common aperture.

Assignees

• Plunk Troy E
• Hopson James E
• Raytheon Co

Inventors

• Plunk Troy E
• Hopson James E

Classifications

• G01S13/883

  for missile homing, autodirectors (missile guidance systems F41G7/22) · CPC title

• G01S13/867

  Combination of radar systems with cameras · CPC title

• H01Q21/064

  using horn or slot aerials (slotted waveguides arrays H01Q21/005) · CPC title

• F41G7/2293

  using electromagnetic waves other than radio waves · CPC title

• F41G7/2286

  using radio waves · CPC title