Apertures

Contributors to Volume I

Preface

Contents of Volume II

Chapter 1 Aperture Theory

I. The Radiated Field

A. Introduction

B. Field Equations

C. Directivity of Scanned Apertures

D. Fresnel Field of a Line Source

E. Fresnel Analysis of a Circular Aperture

F. Near-Field Power Density

G. Focused Apertures

II. Aperture Distributions

A. Introduction

B. Uniform Line Source

C. Cosine Distributions

D. Gaussian Distributions

E. Taylor Line Source

F. Modified Sin πu/πu Distributions

G. Two-Parameter Family

H. Two-Dimensional Distributions

I. Circular Aperture

J. Taylor Circular Aperture

K. Apertures with Gaps

L. Regular Errors

M. Random Errors

III. Pattern Synthesis and Supergain

A. Introduction

B. Sin πu/πu Synthesis

C. The Supergain Phenomenon

D. Directivity Limits Due to Sidelobe Structure

E. Directivity Limits Due to Troposphere

References

Chapter 2 Reflecting Systems

I. Microwave Reflectors in General

A. Seventy-Five Years of Microwave Reflector Development

B. The Geometry of Reflecting Systems

C. Single-Reflector System

D. Two-Reflector Systems

E. Beam Shaping Reflectors

F. Polarized and Polarizing Reflectors

G. Stepped Reflectors and Lensed Reflectors

H. Low-Noise Reflectors

I. Aberrations of Narrow-Field Reflectors

II. Feeds for Microwave Reflectors

A. Classification of Types of Feeds

B. Feed Patterns

C. Feed Polarization

D. Feed Matching

E. Interfeed Coupling and Decoupling

F. Feed Programming and Synthesis

G. Phase Centers

H. Split Focus

III. Reflecting Systems for Radar and Navigation

A. Search and Surveillance

B. Height Finders

C. Trackers

IV. Power-Transmission by Radiation

A. Concentration of Energy. Rayleigh Distance

Β. Friis Transmission

C. Fresnel Correction Factors

D. Focused Apertures

Ε. Illumination Matching

F. Beam Waveguide

V. Reflecting Systems in Space

A. Space Environment

B. Requirements for Reflector Antennas in Space

C. State-of-the-Art Design Approaches

References

Chapter 3 Optical Scanners

I. Azimuth Scanners

A. Luneberg Lens

B. Hourglass

C. Torus

D. Helisphere

E. Surface-Wave Luneberg Lens

II. Sector Scanners

A. Geodesic Luneberg Lens

B. TE10 Luneberg Lens

C. TEM Flat-Plate Luneberg Lens

D. Foster

E. Double-Layer Pillbox

F. Spherical Reflector

G. Lewis

H. Robinson

I. Schwarzschild

J. Constrained Lens

K. Dielectric Bifocal Lens

L. Conflection Doublet

M. Reflectarray

III. Feed Mechanisms

A. Organ Pipe

Β. Ring Switch

C. Multiple-Dish Feed

References

Chapter 4 Radio-Telescope Antennas

I. Introduction

A. Definition and Functions of a Radio Telescope

B. Sensitivity and Resolution

C. Classification of Radio Telescopes

II. Interaction Between Statistical Radio Radiation and Antennas

A. Specifications of Radiation

B. Reception of Quasi-Monochromatic, Partially Polarized Plane Waves

C. Reception of Randomly Polarized Waves from an Extended, Incoherent Source

D. Linear Space Filter Theory of Antennas

III. High-Resolution Radio-Telescope Antennas

A. Fully-Steerable Reflectors

B. Semi-Steerable Reflectors

C. Fixed Reflectors

D. Unfilled Aperture, Mills' Cross

E. Aperture Synthesis

F. Antenna Temperature and Low-Noise Antennas

IV. Radio Interferometers

A. The Principle of a Simple Two-Element Interferometer

B. The Effects of Frequency Bandwidth and Angular Extent of Radio Sources

C. The Multiplying Interferometer

D. The Lobe Sweeping Interferometer

E. The Swept-Frequency Interferometer

F. The Intensity Interferometer

G. Multi-Element or Grating Interferometer

H. The Crossed Multi-Element Interferometer

I. Compound Interferometer

V. Future Radio-Telescope Antennas

References

Chapter 5 Large Radomes

I. Introduction

A. Definition and Function

B. Historical Background

C. General Requirements and Benefits

II. Types of Radomes and General Properties

A. Air Supported

B. Rigid

III. Electromagnetic Characteristics

A. General Considerations

B. General Electrical Specifications

C. Transmission Loss

D. Sidelobe Level Changes

E. Half-Power Beamwidth

F. Boresight Shift

G. Boresight Shift Rate

IV. Survey of Types and Sizes

V. Environmental Design Conditions

A. Winds

B. Precipitation

VI. Structural Design

A. Aerodynamic Loads

B. Stress Analysis

VII. Electrical Design

A. Single-Wall Radomes

B. Half-Wavelength Wall Radomes

C. Foam-Shell Radomes

D. Sandwich Radomes

E. Space-Frame Radomes

References

Appendix I

Tables of Taylor Line Source Distributions

Appendix II

Tables of Taylor Circular Aperture Distributions

Author Index

Subject Index