A wide-band spiral based amplitude-only Azimuth direction finding system

Accuracy improvement in amplitude comparison‐based passive direction finding systems by adaptive squint selection

“…In [19] a practical implementation of a wideband Archimedean two‐arm spiral antenna, suitable for amplitude only DF, is demonstrated. In [20] a system based on amplitude comparison is made and the effect of squint angle on AOA and field of view is discussed. In [21] the development of radio direction finder based on amplitude comparison is shown.…”

Non‐analytical direction‐finding method as a key step in pursuing low size, weight, costs, and computational power in the deinterleaving of radar pulses

“…Despite the efforts to reduce computational complexity in these TOA‐based works, the speed of light imposes a relationship between the sampling rate and the distance between the array antennae on this approach, which makes it impossible for compact equipment to operate with low processing capabilities. Recent amplitude‐based works [16–21] use expressions in analytical form to compare the pulse amplitude (PA) measured on adjacent channels. They need that only the main lobes of antenna patterns be computed, so that their formulae result in bijective functions.…”

“…In [17, 18], FoVs of 40° and 60° are achieved. In [19], a FoV = 103° is achieved, and in [20] a subsystem with FoV = 157° is demonstrated, but only theoretically. Both of [19, 20] are restricted to specific types of antennas and rely on the well‐behaving of their patterns.…”

“…In [19], a FoV = 103° is achieved, and in [20] a subsystem with FoV = 157° is demonstrated, but only theoretically. Both of [19, 20] are restricted to specific types of antennas and rely on the well‐behaving of their patterns. The techniques presented in [16–20] must consider the antenna patterns as analytical functions, so that the DF function can be analytically stated.…”

“…Both of [19, 20] are restricted to specific types of antennas and rely on the well‐behaving of their patterns. The techniques presented in [16–20] must consider the antenna patterns as analytical functions, so that the DF function can be analytically stated. The insertion of extra antennas in order to cover the entire azimuth requires a compensation for their mutual coupling, and problems arise if the system is installed in a platform that introduces interferences on the patterns.…”