RF System Design for Communications · Digital lecture note
Lecture 6 – Noise, Noise Figure, Cascaded Stages, Noise Floor
Haberleşme için RF Sistem Tasarımı – Noise, Noise Figure, Cascaded Stages, Noise Floor
- Course
- RF System Design for Communications (ELM667)
- Semester
- Semester 7 · Fall 2024–25
- Format
- PDF · 16 pages · 0.5 MB · handwriting-style LaTeX
- Language
- Turkish
- Original note
- Ders6.pdf
Open the PDF (0.5 MB)LaTeX source (.tex)Original handwritten note
What is in this note?
Section headings of the note (in Turkish):
- Noise
- Input referred Noise
- How to find input referred Noise
- Noise Figure (NF)dB
- Noise Factor (F)
- Noise in Cascaded Stages
- Noise in Passive Reciprocal Circuit
- Reciprocity
- Noise power in Rx input
- Receive Noise Floor
Text of the note
Show as plain text (Turkish; formulas and drawings are not included)
Input referred Noise
How to find input referred Noise
(1) Cancel sources (gerilim kısa devre, akım açık)
(3) Sum of squares
v_in,n^2 = 4kTγg_m_amplifikatörden
gürültü + 4kTR_s_kaynağın gürültüsü
to decrease v_in,n^2 , increase g_m
genellikle amplifierlar 10,15 dB üstü tasarlanır ki gürültüsü az olsun.
Noise Figure (NF)dB
Claude notu: paydadaki çarpanının karesi alınmamış; muhtemelen ()^2 olmalı.
Noise in Cascaded Stages
→ skaler işlem yapın dB değil!
mutlaka girişte düşük gürültülü ve NF düşük olan amplifier seçilmeli
Noise in Passive Reciprocal Circuit
S_22 → Output Return loss
Reciprocity pasif devrelerde olabiliyor
R_s = R_in Input matched R_L = R_out output matched
[Pasif devrelerde]L_Zayıflatma = 1G = 1A_v^2·R_LR_s
[Noise figürü arttırır]NF_t = L_dB + NF_2
ters olması daha iyi
Onun yerine dar bantlı amfi
Noise power in Rx input
1Hz'lik bantta kT kadar power bulunur
Receive Noise Floor
Noise floor = Receiver input equivalent noise
N_o : output noise power exluding R_s .