Monopulse sum and difference signals with compensation for a failed feed element

Abstract

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.

Analysis and Simulation about a Simplified Model for Modulation and Demodulation of Ship-borne Single Channel Monopulse Radar

“…If the signals f 0 (t), f 1 (t) are limited to a short-term amplitude-stabilized DC signal or periodic signal, and the frequency of the limited periodic signal is much greater than the frequency of the modulated signal, then the average value of the signal can be extracted after every demodulation period [5][6]. Since f 1 (t) is not modulated, the integral term is zero when multiplied by Tz(t), so as to extract the amplitude information of f 0 (t) [7][8], which is…”

Efficient design of a radome for minimised transmission loss

“…Radomes of different thicknesses were tested with the same antenna at a beam angle of 0°, the gain as a function of radome thickness is shown in Fig. 5, using the method described in [17] to create the sum gain. Due to the cost of the units it was not possible to manufacture a large number of radomes that were known to be incorrect.…”

Research on the demodulation method of tracking angular error signal acquired by relay star for spread spectrum users

“…With the development of satellite communication system, some high dynamic and low bit rate spread spectrum users put forward the demand for relay transmission, which requires to improve the ability of relay inter-star link single access antenna Angle tracking receiver, and realize the signal acquisition and tracking and angular error signal extraction for the low bit rate spread spectrum KSA users from 1 kbit/s to 300kbit/s. To realize automatic Angle capture and tracking of low bit rate user target [3][4] .…”