IFI_application_note_107_High Power pulsed field levels

IFI_application_note_107_High Power pulsed field levels -...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Copyright 2009 Instruments for Industry Page 1 Measuring high power RF pulse field levels Application note 107 Purpose - The information supplied in this application note is to provide a better understanding of how measurements can be determined for high power pulse field levels. Although not for every case, customer’s specification, and/or requirement, these high power pulse field levels are largely defined and determined by or from the DO-160 standard. Many of these requirements are due to the increased applications of pulse modulation technologies that are being employed for communications and other high technology applications and are therefore being incorporated into commercial and military Radiated Susceptibility (RS) test standards. It is then a necessity to be able to test with common available lab equipment if you are performing testing at high power pulse field levels. This application note explains and illustrates how the field levels are determined. It also illustrates the relationship of amplifier power to antenna gain. (See our application note 105 “antenna terms and related formulas” for more detailed information.) Introduction - The DO-160 Standard requires two basic types of pulse modulations, SW or Square Wave Modulation and PM or Pulse Modulation. The purpose and function of this application note will be to describe and discuss the high power pulse field levels as required by many applications including category L of the DO-160 standard related to Pulse Modulation. Pulse modulation “PM” requires that the pre-calibrated carrier be modulated to 100% depth with an on-off ratio of 40 dB. The key issue with the 100% modulation pulse or “PM” is that the measurement of the peak pulse field is considerably more complex to measure as compared to the “SW” modulation. The basic techniques and associated test equipment will be the principal focus of this application note. Pulse field terms and characteristics - For Pulse Modulation (Reference Figs. 1 and 2, pg. 2) Carrier Level - The pre-calibrated RF/microwave field producing signal Modulation Depth - The level or amplitude of the pulse modulation signal. Pulse Repetition Frequency (PRF) - The number of pulses per second (ON and OFF time included.) Pulse Width - The length or duration of an RF pulse “ON” time Duty Cycle – The ratio of the “ON” to “OFF” time of a pulse modulated signal
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Copyright 2009 Instruments for Industry Page 2 Pulse parameters – In addition to understanding the amplitude aspects, working with pulsed fields require the user understand the key pulse characteristics of pulse width, pulse repetition frequency or rate, and duty-cycle. By the application of basic mathematics, any third parameter can be calculated from the other two. (see figs 1-2, pg. 2) Pulse Width - Pulse width refers to the period of time that a pulse is actually on. Pulse Repetition frequency -
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 13

IFI_application_note_107_High Power pulsed field levels -...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online