Browsing by Author "Myburgh, Kobus"
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- ItemThe design and development of a co-pulse IFM receiver(Stellenbosch : Stellenbosch University, 2015-12) Myburgh, Kobus; De Swardt, J. B.; Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.ENGLISH ABSTRACT: The instantaneous frequency measurement (IFM) receiver is normally a subunit used in electronic warfare receivers. Its purpose is to measure the frequency of pulse and continuous wave signals over a very wide bandwidth and power dynamic range. It should be noted that the band of interest can range from 500 MHz to 40 GHz. This is an extremely wide bandwidth. These receivers have a very high resolution (typically 1 MHz) over this very wide bandwidth and the error of these receivers is typically a few megahertz. The IFM receiver should reveal the presence of signals. It is not generally known in advance whether signals are present, even if they are, nor their frequency and other characteristics. An inherent disadvantage of all traditional IFM receivers is that overlapping pulses within the same power range corrupt the discriminator outputs to the extent that frequency measurements appear random. This is particularly bothersome, as high duty cycle and continuous wave emitters reduce the frequency measurements to little value. This thesis entails the design and development of an IFM receiver (co-pulse IFM receiver) that can distinguish overlapping pulses within the same power range. Different acquisition receivers were researched to make sure that the IFM receiver is still the best option, taking bandwidth, frequency resolution/accuracy and throughput time (latency) into consideration. The traditional IFM receiver was researched and simulated in MATLAB. While researching the traditional IFM receiver, literature was discovered that identified Prony’s method as a solution to distinguish overlapping pulses (simultaneous signals). Literature proposing Prony’s method that had been submitted from as early as 1989 was found. However, no evidence of the use of the method in current commercial IFM receivers was found, indicating that the implementation of Prony’s method is the difficult part. Prony’s method was simulated in MATLAB, then implemented, simulated and tested in hardware. The results of the hardware implementation were documented and demonstrated a solution to distinguish overlapping pulses.