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Cascaded Receiver Calculator
Chain 2 to 20 blocks (filters, amplifiers, mixers) and get the whole receiver's gain, noise figure, intercept, MDS and dynamic range. Every equation comes from EMRFD chapter 6.
Your signal chain
Presets: EMRFD Figs 6.64, 6.65, 6.66 and 6.67. Leave NF blank on a filter, pad or diode mixer: its noise figure equals its loss.
For Fig 6.65 the book prints IIP3 = −25.5 dBm, while the stage values give −24.6 dBm by Eq 6.14. See Sources.
Antenna on the left, IF on the right. Tap a block to edit its gain, noise figure and IP3. The bar under each block shows how much of the chain's noise it adds.
What it means
How it builds up, block by block
Values at the chain input after each block.
Stage by stage
Cumulative values are measured at the chain input, looking through each stage in turn. Noise and IMD shares show which stage sets the chain's NF and IIP3. Eq 6.14 is the book's worst case: it assumes the IM voltages from every stage add in phase (EMRFD p. 6.30).
Sources & verification
All equations are from Hayward, Campbell & Larkin, Experimental Methods in RF Design (EMRFD), ARRL, 1st ed. (2003). Noise figure: the two-stage cascade equation (Friis), EMRFD p. 6.11, Eq 6.11, applied stage by stage; a passive block's NF equals its loss (same page). MDS: EMRFD p. 6.11, Eq 6.10, with kT = −174 dBm/Hz at 290 K. Intercept: EMRFD p. 6.30, Eq 6.14, with every stage's intercept moved to the chain input by the gain ahead of it (IIP3 = OIP3 − gain). Dynamic range: EMRFD p. 6.30, Eq 6.15. Eq 6.14 is the book's worst case: it assumes the IM voltages from every stage add in phase (EMRFD p. 6.30). Real chains often do a little better. Each equation was checked against the page images and the authors' EMRFD errata (Sept 25, 2020), which has no corrections to them. Automated tests check the engine against EMRFD's worked examples: Figs 6.30 and 6.31 (pp. 6.11–6.12) and Figs 6.63–6.67 (pp. 6.29–6.31). For Fig 6.65 the book prints IIP3 = −25.5 dBm, while its stage values give −24.6 dBm by Eq 6.14. Leaving out the first 1 dB filter gives −25.6 dBm, close to the printed value. The errata doesn't mention it, and the dynamic range still rounds to the printed 78 dB. Engine: .