Subelement B: Transmitting Systems – 8 Key Topics – 8 Exam Questions— Topic 14: Pulse Forming Networks Modulation
Question 8-14B3
Element 8 (RADAR)The purpose of the pulse-forming network is to:
Explanation
A pulse-forming network (PFN) is a specialized electrical circuit, typically comprising inductors and capacitors, engineered to generate a precisely shaped rectangular voltage or current pulse. Its primary function is to store electrical energy and then discharge it in a controlled manner, creating a pulse of a specific, predetermined duration. This direct control over the energy release means the PFN effectively determines the width of the modulating pulses.
The pulse repetition rate (how often pulses occur) is determined by the external timing or triggering circuit that initiates the PFN's discharge, not by the PFN itself. While PFNs are LC networks, their fundamental purpose is pulse shaping rather than acting as general high-pass or low-pass filters for a broad range of frequencies.
Related Questions
8-14B1 The pulse developed by the modulator may have an amplitude greater than the supply voltage. This is possible by:8-14B2 Pulse transformers and pulse-forming networks are commonly used to shape the microwave energy burst RADAR transmitter. The switching devices most often used in such pulse-forming circuits are:8-14B4 The shape and duration of the high-voltage pulse delivered to the magnetron is established by:8-14B5 Pulse-forming networks are usually composed of the following:8-14B6 An artificial transmission line is used for: