RF fundamentals

This hands on course combines clear RF theory with live measurement and practical experimentation. Delegates explore frequency, wavelength, power, spectrum, propagation, antennas, transmission lines, modulation and multiple access, then immediately see those principles in action. Using spectrum analysers, signal generators, oscilloscopes and SDR, they capture real signals, measure power and loss, observe modulation and calculate link budgets. Rather than theory alone, the course focuses on what RF looks like in practice, how it behaves in real environments and how performance can be predicted and verified.

Prerequisites

None.

Objectives

By the end of the course delegates will be able to:

• Analyse RF signals using spectrum analysers.

• Explain how modulation and multiple access enable modern wireless systems.

• Predict signal levels using dB/dBm calculations.

• Measure transmission line attenuation and verify power loss.

• Predict coverage using propagation and path loss principles.

What is RF?
Radio, Frequency, electromagnetic waves and spectrum, frequency, wavelength, amplitude, phase, Hertz, the radio spectrum, natural vs man made RF, RF safety.

Hands on: Use a spectrum analyser to pick up live transmissions, identify frequencies and measure power, including PMR.

RF systems
Basic RF system, Tx, Rx, RF signals, RF system categories, common properties. Radio spectrum use, world radio regions, standards, regulation, UK spectrum, bandwidth. Throughput vs bandwidth, simplex, half/full duplex.
Hands on: Generate RF signals with a signal generator, connect test equipment, locate and interpret frequencies.

RF propogation

Electromagnetic fields and waves, propagation, Free space path loss, interference, power, radio wave propagation, the atmosphere, surface and space waves, electrical properties, polarity, frequency, LOS, hop distance, diffraction, refraction, reflection, absorption, scattering, radiation, multipath. Solar radiation.

Hands on: Measure signal strength in different environments, demonstrate shielding with a faraday pouch.

Antennae
What an antenna does, transducers, Isotropic radio source, gain, EIRP, beamwidth, polarisation, polar diagrams, directional, semi and omni directional, basic antenna designs, Antenna examples: half wave dipole, dish,yagi… antenna arrays, sizing.
Hands on: Compare antennas on the same signal and observe pattern, efficiency and mismatch effects.

Transmission lines

What is a transmission line? Behaviour, copper, coaxial, micro strip, balanced lines, impedance, attenuation, insertion loss, return loss. Common connector types, measuring transmission lines.

Hands on: Measure power loss along transmission lines and visualise behaviour using a spectrum analyser and oscilloscope.

Wireless systems

Cellular (GSM, UMTS), Wifi, WiMax, others: GPS, DBS, RFID, radar, Bluetooth.

Hands on: cellular

Spread Spectrum technologies

Spread spectrum benefits and disadvantages, how it works, Direct Sequence, Frequency Hopping, hybrids.

RF propagation

Models, link budget, Smith chart, RF matching with the Smith chart. cell capacity, tradeoffs: power vs. bandwidth, free space, reflection, diffraction, multipath cancellation, propagation prediction and measurement tools.

Hands on: Smith charts.

Modulation

What is modulation? Baseband signals and carriers, analog and digital modulation, AM, FM, PM, keying, FSK, PSK, QPSK, QAM, symbols vs bits, channel capacity.

Hands on: View carriers and modulation on the oscilloscope and relate symbols to real signals.

Multiple access schemes
The need for multiple access, Issues with multiple access, FDMA, TDMA, CDMA, OFDM, OFDMA, Multiple access in real systems. Comparing modulation versus multiple access.

Hands on: Use SDR to observe contention, frequency sharing and time division in live signals.

Wireless systems
Classification by function: Broadcast, Fixed, Mobile: Point to point, point to multipoint, classification by range. Satellite systems, satellite hop, satellite orbits. Microwave links. Microwave letter bands. Cellular 1G to 5G, 5G architectures, UK cellular frequencies, 5G low, mid and high frequencies. WiFi, Access points, multi cell WiFi, WiFi4 (802.11n) to WiFi7. UK license exempt bands.
Hands on: Capture and decode live air band transmissions using SDR.

RF math

Power is measured in Watts. Power and mW. Power examples and safety, Decibel. dB, dBm, dBm to mW conversions, Rule of 3s and 10s. SNR, SNR and dB, SNR levels, RSSI, RSSI vs SNR.

Hands on: Measure signal levels, insert attenuation, predict results and verify in real time.

Link budgets
What are link budgets, link budget calculations, IR, EIRP, free space path loss, fresnal zone, precipitation, noise sources, interference.
Hands on: Build and validate a simple end to end link budget.

RF testing and measurement

Review of equipment used in course: spectrum analysers, signal generators, oscilloscope. Other equipment.