RF System Design for Communications · Digital lecture note
Midterm study – Nonlinearity, noise, dynamic range
Haberleşme için RF Sistem Tasarımı – Vize çalışması: Doğrusal olmama, gürültü, dinamik aralık
- Course
- RF System Design for Communications (ELM667)
- Semester
- Semester 7 · Fall 2024–25
- Format
- PDF · 30 pages · 0.7 MB · handwriting-style LaTeX
- Language
- Turkish
- Original note
- Not.pdf
Open the PDF (0.7 MB)LaTeX source (.tex)Original handwritten note
What is in this note?
Section headings of the note (in Turkish):
- Power and Phasor
- Complex power
- Maximum power
- 1 Harmonic distortion
- 2 Gain compression
- 3 Desensitization
- 4 Intermodulation
- Noise
- Input referred Noise
- How to find input referred Noise
- 1 Cancel sources (gerilim kaynağı kısa, akım kaynağı açık devre)
- 3 Sum of squares
- Noise Figure (NF) / Noise Factor (F)
- 1 Noise coming from R_s (v_n^2=0, I_n^2=0)
- 2 Noise coming from v_n^2 (v_n,R_s^2=0, I_n^2=0)
- 3 Noise coming from i_n^2 (v_n^2=0, v_n,R_s^2=0)
- Noise in Cascaded Stages
- Noise in passive Reciprocal Circuit
- Reciprocity
- Noise power in Rx input
- Receive Noise Floor
- Receiver noise Floor
- Receiver SNR & Noise
- Calculate NF total
- Sensitivity and Dynamic Range
- Dynamic Range
- SFDR
- Spur-free Dynamic Range
Text of the note
Show as plain text (Turkish; formulas and drawings are not included)
Power and Phasor
a_1, a_3 have different signs
girişin genliği çok yükselirse kazanç düşer
ω_1 frekansında olan sinyal:
Vericinin ikinci harmoniğine kadar bastırılmalıdır ki bu alıcı
en az 45 dB bastırılmalıdır.
if system linear ⇒ a_1A
if A_IIP3 more linear system
Compute IIP3 of the amplifier such that IM3 product falling at ω_3 is 20 dB below the desired signal ? ( → A_o,IM3 ??, → A_o,s )
Input referred Noise
3 Sum of squares
To decrease v_in,n^2 , increase g_m
genellikle amplifierlar 10,15 dB üstü tasarlanır ki gürültüsü az olsun
Noise Figure (NF) / Noise Factor (F)
[önemli]F = SNR_inSNR_out > 1
sadece kaynağa bağlı
Basılı gürültü modeli şeması ( V_s , R_s , v_n^2 , i_n^2 , gürültüsüz A_v kutusu, R_in ); el yazısıyla v_n,R_s^2 kaynağı eklenmiş
R_P R_s → No noise effect coming from R_P
Çalışma sorusuna bak
Noise in Cascaded Stages
mutlaka girişte düşük gürültülü ve NF düşük olan amplifier seçilmeli
Noise in passive Reciprocal Circuit
pasif devrelerde olabiliyor
Noise figure artırır
Noise power in Rx input
1Hz'lik bantta kT kadar gürültü gücü bulunur
Receive Noise Floor
Noise floor = Receiver input equivalent noise
N_o : output noise power excluding R_s kaynak gürültü düşünülmediğinde
Receiver noise Floor
Receiver SNR & Noise
output noise = input noise + N_A
Calculate NF total
Calculate Noise floor B = 5 MHz
Sensitivity and Dynamic Range
Sensitivity is the minimum which can be detected at output P [dBm]
A GSM receiver has
what is the minimum acceptable signal power ?
Spur-free Dynamic Range