Monopulse antenna systems are commonly used in airborne radar as they give angular information in a single measurement. For amplitude based monopulse antenna systems, multiple overlapping beams are sent out from the antenna feed elements. These signals may then be re‐combined using a comparator network to form the sum and difference signals, which provide angular information relating to the target position. This study investigates a proposed method by which the individual feed element signals from the monopulse antenna are captured and combined in software, thus removing the need for a hardware comparator behind the feed elements. Results of a sum and difference signal created by a comparator and by this proposed method are compared. This study then verifies a method by which the individual feed element signals from the monopulse antenna are captured, combined in software and presents a novel method to compensate for a failed feed element signal, verified in both simulation and anechoic chamber measurements. It is shown that this new compensation for a single failed feed element works well for a signal in the centre of the monopulse antenna, where gain and sum patterns are shown to be conserved.

A radome has to be carefully designed to ensure it has minimum impact on the performance of the antenna. Traditional approaches involve equation approximations, complex ray tracing, iterative manufacturing process and or electrically large and lengthy Electromagnetic (EM) simulations. The novel approach described in this paper involves a 2D Ray Tracing Method (2DTRM) simulation in MATLAB and an electrically small unit cell simulation in HFSS. This new approach gives an optimal thickness result that is only 0.004mm different to that of a full EM simulation. The radome is manufactured and Radio Frequency (RF) tested in an Anechoic Chamber (AC), the calculated thickness is shown to be the optimal thickness.

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This paper presents a novel axis transform for a 3 axis positioner system located in an anechoic chamber. It allows for the true measurement of a twist reflector antenna with a radome. This progresses the field of antenna measurement as, uniquely, this axis transform allows the measured aberration caused by the antenna radome to be included. Simulated and measured results are shown to validate the use of the proposed transform.