Introduction to RF Radiation Safety FAQ

Chapter 2 FAQ

1. 2.7.1 What Is the Difference Between Analog and Digital Signals
   1. What Is an Analog Signal?
   2. What Is a Digital Signal?
   3. Why Are Most Modern Communications Systems Digital?
   4. What Are the Advantages of Digital Signals?
   5. Are There Any Advantages to Analog Signals?
   6. Are Communications Systems Ever Completely Digital?
   7. How Are Analog Signals Converted into Digital Signals?
   8. Will Analog Communications Disappear Completely?
2. 2.7.2 What Is a Sinusoidal Wave and Why Is It Important
   1. What Is a Sine Wave?
   2. Why Is the Sine Wave So Important?
   3. What Are Amplitude, Frequency, and Phase?
   4. What Is the Difference Between Frequency and Angular Frequency?
   5. What Is the Relationship Between Frequency and Wavelength?
   6. Why Can Complex Signals Be Represented by Sine Waves?
   7. What Are Harmonics?
   8. Why Do Engineers Often Analyze Signals in Terms of Frequency?
   9. Where Are Sinusoids Used in Communications Systems?
3. 2.7.3 What Is the Frequency Domain and Why Do Engineers Use It
   1. What Is the Difference Between the Time Domain and the Frequency Domain?
   2. Why Do Engineers Use the Frequency Domain?
   3. What Does a Signal Look Like in the Frequency Domain?
   4. What Is Fourier Analysis?
   5. How Can Complex Signals Be Broken into Simple Sine Waves?
   6. What Are Harmonics?
   7. Why Is the Frequency Domain Useful for Understanding Bandwidth?
   8. How Does the Frequency Domain Explain Filtering?
   9. Why Is the Frequency Domain Important in Radio Communications?
   10. How Is the Frequency Domain Used in Digital Communications?
   11. What Is a Spectrum Analyzer?
   12. Which Is More Important: The Time Domain or the Frequency Domain?
4. 2.7.4 What Is Bandwidth and Why Is It Important
   1. What Does Bandwidth Mean?
   2. Why Is Bandwidth Important?
   3. How Is Bandwidth Measured?
   4. Why Do Different Signals Require Different Bandwidths?
   5. Why Does a Sine Wave Occupy So Little Bandwidth?
   6. Why Does a Square Wave Require Infinite Bandwidth?
   7. What Happens When Bandwidth Is Limited?
   8. What Is Inter-Symbol Interference (ISI)?
   9. How Does Bandwidth Affect Data Rate?
   10. Is More Bandwidth Always Better?
   11. What Is Spectral Efficiency?
   12. How Do Filters Affect Bandwidth?
   13. Why Is Bandwidth Valuable?
   14. How Does Bandwidth Influence Modern Communications?
   15. Is Bandwidth the Same as Internet Speed?
5. 2.7.5 What Frequencies Are Used for Communications
   1. What Is the Electromagnetic Spectrum?
   2. What Are Audio Frequencies and Radio Frequencies?
   3. What Are the Main Radio Frequency Bands?
   4. What Are VHF, UHF, and Microwave Frequencies?
   5. Why Do Different Services Use Different Frequencies?
   6. Why Do Mobile Phones Use UHF and Microwave Frequencies?
   7. Why Do Satellite Systems Use Microwave Frequencies?
   8. What Frequencies Are Used by Fiber-Optic Systems?
   9. What Is Free-Space Optical Communication?
   10. What Are Terahertz Communications?
   11. How Does Frequency Affect Antenna Size?
   12. Will Communications Systems Continue to Move to Higher Frequencies?