Chapter 6: Electromagnetic and Communication System¶
Syllabus: AEiE06
Coverage: AEiE0601 through AEiE0606; the unnamed antenna “theorem” remains source-uncertain
Status: DRAFT - syllabus and assigned-question pass complete; independent source audit pending
Exam use: Field-unit recognition, wave relations, communication blocks, transform properties, and DSP discrimination MCQs
Chapter map¶
| Code | Area | Fast recognition cue |
|---|---|---|
AEiE0601 |
Electric field and magnetic field | \(E,D,H,B\), divergence, potential, dipoles, boundaries |
AEiE0602 |
Wave propagation and antenna | Maxwell, plane waves, reflection, waveguides, TE/TM, antennas |
AEiE0603 |
Communication system | Analog/digital blocks, AM/FM/PM, bandwidth, noise |
AEiE0604 |
Data communication and information theory | Sampling, PCM, quantization, Shannon, multiplexing, line coding |
AEiE0605 |
Signal and system | LTI, convolution, Fourier series and transforms, PSD/ESD |
AEiE0606 |
Digital signal processing | \(z\)-transform, ROC, DFT, circular convolution, FIR/IIR |
Chapter rapid-revision sheet¶
| Topic | Must-remember cue |
|---|---|
| Field symbols | \(E,D,H,B\) must never be swapped |
| Core constitutive laws | \(D=\epsilon E\), \(B=\mu H\) |
| Electrostatic potential | \(E=-\nabla V\) |
| Free-space constants | \(c\approx3\times10^8\) m/s, \(\eta_0\approx377\ \Omega\) |
| Ambiguous ratio warning | \(E/B=c\), but \(E/H=\eta_0\) |
| Waveguide | Rectangular guide dominant mode TE\(_{10}\) |
| Modulation | AM amplitude, FM frequency, PM phase |
| Sampling | \(f_s\ge2f_m\) |
| Capacity | \(C=B\log_2(1+\text{SNR})\) with linear SNR |
| LTI systems | Output by convolution with impulse response |
| ROC | Causal rational ROC outside outermost pole |
| Stability | ROC must include unit circle |
| DFT | Multiplication in DFT domain gives circular convolution |
| FIR/IIR | FIR finite and phase-friendly; IIR recursive and efficient |
Assigned-question audit¶
| Target | Deciding fact | Result |
|---|---|---|
set1-031 |
\(E=-\nabla V\) | Supported by AEiE0601 |
set1-032 |
with \(\mu\) and \(\sigma\) fixed, skin depth varies as \(1/\sqrt f\) | Supported by AEiE0602 |
set1-033 |
FM is used for high-fidelity broadcast audio and permits amplitude limiting before demodulation | Supported by AEiE0603 |
set1-034 |
quantization maps amplitudes to finite levels and introduces quantization error | Supported by AEiE0604 |
set1-035 |
PSD is conventionally measured in W/Hz | Supported by AEiE0605 |
set1-036 |
causal rational ROC is outside the outermost pole; stability also requires the unit circle | Supported by AEiE0606 |
set1-081 |
\(E=-\nabla V\) | Supported by AEiE0601 |
set1-082 |
Hilbert transform shifts positive frequencies by \(-90^\circ\) and negative frequencies by \(+90^\circ\) | Supported by AEiE0603 |
set1-083 |
for magnetic flux density \(B\), \(E/B=c\); for field intensity \(H\), \(E/H=\eta_0\) | Supported by AEiE0602 |
set1-084 |
windowing controls Gibbs sidelobes while trading side-lobe level against main-lobe width | Supported by AEiE0606 |
Sources and verification note¶
- Coverage authority: NEC syllabus in
syllab.mdforAEiE0601throughAEiE0606. - Recommended electromagnetics verification: Sadiku, Elements of Electromagnetics; Hayt and Buck, Engineering Electromagnetics; Cheng, Field and Wave Electromagnetics; Balanis for antennas.
- Recommended communication verification: Lathi and Ding, Modern Digital and Analog Communication Systems; Haykin, Communication Systems.
- Recommended signal and DSP verification: Oppenheim, Willsky, and Nawab, Signals and Systems; Oppenheim and Schafer, Discrete-Time Signal Processing; Proakis and Manolakis, Digital Signal Processing.
- Standards-level constants and terminology: SI units, classical free-space constants, and widely accepted communications notation are used.
- Verification posture: this is a review-dense first edition, not a fully source-annotated monograph. Field-variable definitions and formula conditions remain explicit so similar-looking quantities are not interchanged.