В настоящей книге даны виды, характеристики антенн, а также принципы выбора антенных систем для приёма радио и телевидения, включая спутниковое. По приведённым рекомендациям вы сможете изготовить ту или иную антенну собственными силами, установить её и провести необходимую настройку.

Harold Wheeler, in his classic 1947 papers (Wheeler, 1947a, 1947b), created the field of electrically small antennas (ESA), although, as shown in the history (Appendix A), the early antennas were all electrically small. This field has long been important for frequencies below roughly 1 GHz, where a half-wavelength is about 6 in. These electrically small antennas have characteristics in common that limit performance: low radiation resistance, high reactance, low efficiency, narrow bandwidth, and increased loss in the matching network. Most of these limitations are shared by two other classes of antennas: superdirective antennas and superconducting antennas. The original intent was to update Electrically Small, Superdirective, and Superconducting Antennas with a second edition. Sufficient material became available to broaden the scope of that book; the result is this book with a new title. This book provides mathematical foundations for important topics including ENG shells, ESA with m or « cores, including lossy cores, and focused/subwavelength imaging. Chapter 1 contains detailed electromagnetic derivations of Chu and Thal Q formulations, formulas for Q when m or « cores are used, and effects of loss on Q. Finally, work on fundamental limitations using spheroids instead of the radian sphere is covered. Chapter 2 is a treatise on bandwidth and matching, and Foster’s reactance theorem. Precise data are given for Fano’s matching limitations and bandwidth improvement. The effects of loss in matching circuits and cables on VSWR are shown. The relatively new field of non-Foster matching is next discussed. Finally, performance of a short monopole that is matched is compared with that of monopole with high-impedance preamp. Chapter 3 provides updated coverage on canonical antennas: dipoles, loops, self-resonant ESA, PIFA, and dielectric resonator antennas. A comparison is made of Q of various antennas with the Chu–Thal fundamental limitation. In Chapter 4 are presented six ideas that are clever but with performance numbers that are poor. Eighteen nutty antenna ideas are detailed in Chapter 5; the list keeps growing! Chapter 6 on superdirective antennas has been updated with recent data on the use of self-resonant elements. These allow modest supergain but bandwidth and tolerance limitations remain. Also included is new material on maximum directivity of arrays. The last chapter, on superconducting antennas, has been updated with new delay line data. The earlier conclusion that superconductors should be considered for the matching network, but not the antenna, still holds. Aworld history of ESA is presented in Appendix A. Antenna terms important to ESA are defined in Appendix B. Appendix C contains a paper by Karawas and Collin (2008) on NIM shells enclosing an ESA dipole. The analytical errors associated with perfect lenses and subwavelength focusing are treated in detail by Collin (2010) in Appendix D. Each chapter includes extensive references. An overall subject index and an author index are provided at the end of the book. We antenna engineers have done what is possible by rearranging the wires; future significant advances will come through the use of new low-loss magnetic materials and through the use of circuits to compensate for impedance deficiencies.