Study of Gain Limitations and Pattern Synthesis of Traveling Wave Antennas

摘要

Phase and/or amplitude modulation resulting in a spatial spectrum of sinξ/ξdistributions has been investigated. The phase is considered as a Fourier series with each sine or cosine term of the series giving an infinite but rapidly converging series of sinξ/ξdistributions. Each sinξ/ξdistribution is due to a relative wavenumber in the spectrum where the relative wavenumber (δ) is defined so thatδ> 1 is the slow wave region.nDistributions ofδi, the instantaneous relative wave-number along the array, giving high gain endfire arrays have been obtained and fall into three classes: (1) Input to end tapers; - the relative wavenumber is high at the input and approximately one at the end of the array; (2) Ends to center tapers; - the relative wavenumber is high at the ends and approximately one at the center; and(3) Periodic tapers; - the relative wavenumber decreases to approximately one and then increases, decreases, etc.