Electrooptical Arrays

1 Array Antennas with Coherent Optical Signal Processing.- 1.1 The Potential for Parallel Processing of Space—Time Signals with Coherent Optical Techniques.- 1.2 Electrooptical Array Antennas. Background and State of the Art.- 1.2.1 Structure of the electrooptical array.- 1.2.2 Types of electrooptical arrays.- 1.3 The Components of an Electrooptical Array Antenna.- 1.3.1 General information.- 1.3.2 Space—Time light modulators in an electrooptical array.- 1.3.3 Output devices.- 2 Formation of Planar Array Antenna Patterns.- 2.1 Pattern Control Characteristics of Electrooptical Planar Arrays.- 2.2 Accuracy, Power and Range Properties of Electrooptical Arrays.- 2.2.1 Accuracy.- 2.2.2 Power.- 2.2.3 Range properties.- 2.2.4 Transformation of the information block.- 3 Array Antennas with Space—Time Signal Processing.- 3.1 Pattern and Spectrum Shaping Characteristics of Linear Electrooptical Arrays Using Multichannel Acoustooptical Space—Time Light Modulation.- 3.1.1 Coherent optical regeneration of the frequency angular spectrum.- 3.1.2 Precision and power characteristics.- 3.1.3 Comparison of Raman-Nath and Bragg diffraction in coherent optical processors.- 3.1.4 Transformation of the information block.- 3.2 Linear Electrooptical Array with Electron Beam and Optical Signal Addressing Input Devices.- 3.2.1 Pattern- and spectrum-forming properties.- 3.2.2 Requirements for space—time light modulators.- 3.3 Coherent Optical Processors for Planar Array Antennas with Space—Time Light Modulator with a Complex Law for Addressing the Input Signal.- 3.3.1 Complex input format.- 3.3.2 Two-dimensional input format.- 3.4 Linear Arrays with Correlation Signal Processing.- 4 Formation of the Antenna Pattern of Nonplanar Array Antennas.- 4.1 The Restoration Algorithm.- 4.1.1 The coherent optical processing algorithm.- 4.1.2 Characteristics of the algorithm.- 4.2 Implementing the Processing Algorithm with Coherent Optics.- 4.2.1 Piecewise planar arrays.- 4.2.2 Array antennas on the surface of a circular cylinder.- 4.2.3 Circular arrays.- 4.3 Random Axially-Symmetric Array Antennas.- 4.3.1 Description of the algorithm.- 4.3.2 Coherent optical processor employing a volume filter.- 4.3.3 Implementing the processor.- 4.3.4 The axially symmetric electrooptical array.- 4.4 Phase Correction Method.- 5 Discreteness Effects in Planar and Nonplanar Electrooptical Antenna Arrays.- 5.1 Arbitrary Nonplanar Electrooptical Antenna Array.- 5.1.1 Redundancy of the starting processing algorithm.- 5.1.2 Effect of finite channel widths on the space—time light modulator.- 5.1.3 Interference between channels in the modulator.- 5.2 Effects of Discreteness of Planar Electrooptical Antenna Arrays.- 5.2.1 Simplification of the Fourier processor.- 5.2.2 Pupil effect of modulator channels.- 5.2.3 Effect of interference between modulator channels.- 5.2.4 Methods of eliminating ambiguity in the determination of coordinates.- 5.3 Effects of discreteness of cylindrical electrooptical arrays.- 5.3.1 Reduction of the coherent optical processor of cylindrical arrays.- 5.3.2 Pupil effect of modulator channels.- 5.3.3 Effect of interference between modulator channels.- 6 Rejection of Interference by Coherent Optical Methods.- 6.1 Statement of Problem Choice of Criterion.- 6.2 Interference Suppression Processing Algorithm and Options for Its Implementation.- 6.2.1 Processing algorithm.- 6.2.2 Options for realizing the processor.- 6.2.3 Structure of the mask.- 6.3 Processor with Ideal Suppression of Spatial Noise Signals.- 6.3.1 Evaluation of the depth of suppression.- 6.3.2 Generation of ideal nulls.- 6.3.3 Comments.- 6.4 Examples of Electrooptical Arrays with Noise Rejection.- 6.4.1 Planar electrooptical antenna array with arbitrary aperture shape.- 6.4.2 Linear and planar electrooptical antenna arrays with rectangular apertures.- 6.4.3 Planar electrooptical array with circular aperture.- 6.5 Generalization of the Coherent Optical Method of Noise Rejection.- 6.5.1 Suppression of sectorial noise.- 6.5.2 Linear electrooptical arrays with space—time light modulators using spatial scanning of a time signal.- 6.5.3 Cylindrical electrooptical array.- 6.5.4 Effect of discreteness of the array and the space—time light modulator.- 6.6 Effect of Errors in the Realization of the Spatial Filter on the Depth of Null Formation.- 7 The Influence of Uncertainties on Electrooptical Arrays.- 7.1 The Electrooptical Array Antenna Gain.- 7.2 Coherent Optical Processor Errors.- 7.2.1 The effect of the pupil and space—time light modulator channel interaction.- 7.2.2 Potential accuracy and the coherent optical processor optical system aberrations.- 7.2.3 Coherent processor element misalignment.- 7.2.4 Spatial incoherence of the reading light.- 7.2.5 Time incoherence of the light source.- 7.2.6 Fresnel light reflection from coherent optical processor elements.- 7.2.7 Limiting the dynamic range.- 7.3 Space—time Light Modulator Distortion Factors.- 7.3.1 Dual-band input.- 7.3.2 Space—time light modulator modulation characteristic nonlinearity.- 7.3.3 Zero order diffraction.- 7.3.4 The presence of distortion in coherent optical processors with AOM-based input devices.- 7.3.5 Non-linear distortions in coherent optical processors with input devices based on space— time light modulators with electronic and optical addressing [107].- 7.3.6 Comments.- 8 Electrooptical Array Sensitivity.- 8.1 Thermal Noise in Electrooptical Arrays.- 8.1.1 External thermal noise.- 8.1.2 Internal thermal noise in electrooptical arrays.- 8.2 Quantum Noise in Electrooptical Array with Incoherent Photodetection.- 8.3 Quantum Noise in Electrooptical Array Antennas with Coherent Photodetection.- 8.4 Electrooptical Array Sensitivity Evaluation.- 9 Coherent Optical Processors for Electrooptical Array Antennas Examples Components Research.- 9.1 Coherent Optical Processor for Forming the Radiation Pattern of Planar Array Antennas.- 9.1.1 The coherent optical processor and its components.- 9.1.2 Forming the angular spectrum.- 9.1.3 Defocusing (suppressing) the adjacent image using an equivalent lens.- 9.1.4 Coherent (heterodyne) photodetection.- 9.2 Coherent Optical Processors for Space—Time Processing of Linear and Planar Array Antenna Signals.- 9.2.1 Coherent optical processor for linear array antennas which forms frequency-phase signals with the space—time light modulator with multichannel optical addressing.- 9.2.2 Coherent optical processor for planar array antennas with complex signal recording.- 9.3 Coherent Optical Processor for Planar Array Antennas with Rejection of Interfering Spatial Signals.- 9.3.1 Coherent optical processor and its components.- 9.3.2 Experimental results and discussion.- 9.4 The Circular Array Antenna Coherent Optical Processor.- 9.4.1 The coherent optical processor and mask recording.- 9.4.2 Experimental results and discussion.- 9.4.3 A Coherent optical processor for a circular array antenna employing a pattern-forming mask synthesized by digital holography.- 10 Conclusions Trends in Electrooptical Array Antenna Theory and Development.- A Circular Electrooptical Array Antenna Mask Synthesis by Digital Holography Methods.- A.1 The Complex Mask Transmission Function.- A.2 The Mask Structure.- A.3 The Mask Diffraction Efficiency.- A.4 Shifting to the Spatial Subcarrier Frequency.- A.5 Mask Recording by Digital Holography.- A.6 Numerical Evaluation of the Mask.- B Evaluation of the Diffraction Efficiency of Coherent Optical Processors.- C Notes on Calculating Extended Spheroidal Functions and Related Functional.- D Electrooptical Arrays Focused in the Fresnel Region.- D.1 The Reproduction Algorithm.- D.2 Planar Electrooptical Arrays.- D.3 Linear Electrooptical Arrays.- D.4 Linear Electrooptical Arrays with an Optical Spectroanalyzer.- D.5 Cylindrical Electrooptical Arrays.