Haberleşme için RF Sistem Tasarımı · Dijital ders notu
Direct conversion alıcı, dezavantajları, I/Q mismatch
- Ders
- Haberleşme için RF Sistem Tasarımı (ELM667)
- Dönem
- 7. Dönem · 2024–2025 Güz
- Biçim
- PDF · 13 sayfa · 0,6 MB · el yazısı görünümlü LaTeX
- Orijinal not
- Ders-12.pdf
The digital notes were created from the handwritten notes with the help of Claude (Anthropic); they are meant as a supplementary resource and may contain errors. Always rely on the original notes and the official course materials.
Bu notta neler var?
- Direct Conversion Receiver
- Drawbacks of Direct Conversion Receivers
- (1) LO Leakage
- (2) DC offset
- Solving DC Offset
- (3) Even Order Distorsion
- (4) Flicker noise
- Flicker noise Penalty
- I/Q Mismatch (Drawbacks of Quadrature Downconversion)
- Outputs
- Only gain mismatch (θ = 0)
- Only phase mismatch (ε = 0)
- Solutions of I/Q Mismatch
Notun metni
Düz metin olarak göster (formüller ve çizimler yoktur)
Direct Conversion Receiver
→ One step Conversion
Simple design process
Mixing spurs are reduced
FSK Direct Conversion Receiver
Anlamak için 2 bit gönderdiğimizi düşünelim
Şimdi bunları bir demodülatöre sokuyoruz
Drawbacks of Direct Conversion Receivers
To minimize LO leakage
Symmetric layout for Oscillator
DC offsetten kurtulmalıyız
LO leakage at the input of LNA is -60 dBm
Solving DC Offset
modulation index (FSK)
Bunun başka dezavantajı var
Drawback of Direct conversion Receivers
(3) Even Order Distorsion
Mixer layout should be symmetrical
We ignore noise effect below f_BW1000 since they vary slowly
Flicker noise Penalty
Flicker noise penalty
→ normalde f_c ana bant bitiyor formülü uygularken dikkat edin
I/Q Mismatch (Drawbacks of Quadrature Downconversion)
Phase & gain Error
Only phase mismatch ( ε = 0 )
Bunu çözmek için ne yapmak gerekiyor
Solutions of I/Q Mismatch