Introduction to RF Design Theory and Principles - RAHRF201

Analyze a power calculation for a circuit with a 2 ∠30° V source and a 5 + j10 impedance, determining current, impedance magnitude and phase, and the average power.

Define complex power from voltage and current phasors and their conjugate, distinguish active power P from reactive power Q, and examine power in resistors, inductors, and capacitors.

Compute complex power in a 1 MHz circuit by finding omega, impedance, and its conjugate. Derive real and reactive power, and express the power as p and q.

Achieve maximum power transfer in radio frequency design by matching the load impedance to the complex conjugate of the source impedance, delivering the available power and minimizing loss.

Understand dB, dBm and power gain in RF design, including log-domain power and reference levels, and note the difference between off-chip 50-ohm matching and IC design focus on voltage gain.

Explore small signal analysis of a biased transistor by setting the operating point, applying a small ac input, and deriving drain current, voltage variations, gm, and overdrive concepts.

Explain the small-signal transistor model with gm and ro, show the gain as gm times ro in parallel with RL, and emphasize high output resistance in saturation.

Explore how parasitic capacitances in transistors, including diffusion/overlap effects, limit high-frequency RF design; understand fT, unity current gain, and power–speed tradeoffs.

Observe a transistor test circuit in ADS, bias with DC, apply AC input, and sweep frequency to identify current gain and the unity-gain frequency where gain approaches one.

Explore how to determine the input compression point using alpha1 and alpha3 in a differential pair, and analyze linear versus nonlinear amplifier behavior with a gain compression ADS example.

Review harmonic distortion and gain compression in non-linear systems. Explain how single-frequency input generates multiple output components, and how filters attenuate unwanted signals to protect the desired signal.

Explains desensitization in non-linear systems caused by off-channel interference. Shows how nonlinear distortion creates multiple frequencies that can fold into the desired band and reduce gain.

Explore intermodulation in a nonlinear LNA, modeling IP3 effects with a high-amplitude interferer to understand how the unwanted product distorts the desired signal.

Analyze noise power in cascaded RF blocks by using the frequency-domain spectral density and a bank of bandpass filters to determine average power per hertz.

Explore how to analyze input referred noise in noisy circuits by separating noise from the circuit, modeling noise sources, and applying superposition to compute input referred noise.

Compute input referred noise by nulling sources, account for transistor channel and resistor thermal noise in a common source amplifier; note increasing gm reduces input noise.

Compute the circuit's noise figure by summing source and parallel noises, deriving NF = 1 + Rs/Rp, and noting a large Rp reduces noise.

explain noise in cascaded stages and show the total noise figure is dominant for the first stage, while later stages are attenuated by prior gains.

Learn to calculate the input noise power of a receiver, including bandwidth and source noise, and understand how cascaded LNA and mixer stages affect the noise floor.

Calculate the total noise figure for a two-stage cascade by converting f1 and f2 from dB to linear and using f_t = f1 + (f2 - 1)/g1.

Explore two-stage receiver system calculations, focusing on noise figure and noise factor from LNA and mixer, with real-number examples, and examine linearity, IP3, and compression point tradeoffs.

Define sensitivity as the minimum input power needed for detection above noise, and relate it to noise figure, bandwidth, and the noise floor.

Compute the minimum input power for a GSM receiver with 200 kHz bandwidth and a 9 dB noise figure, showing minus 103 dBm as the threshold to avoid data errors.

Analyze the transfer function of series RLC circuits, revealing a band-pass response with resonance at f0 and a half-power bandwidth, tied to the quality factor Q.