類比通訊系統 2008/11/24 金正元

Outline Introduction Transmission Line Filter Amplifier Mixer

Introduction You are going to complete this part. 980MHz 900MHz

Introduction Crystal Oscillator at 100MHz and BPF 900MHz

Introduction

What’s Transmission Line? A transmission line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic waves or acoustic waves, as well as electric power transmission. Components of transmission lines include wires, coaxial cables, dielectric slabs, optical fibers, electric power lines, and waveguides.

Miscellaneous Transmission Lines

Design 中心頻率 (980MHz) 傳輸線結構 (microstrip line) 板材 (FR4) 板子厚度 (0.8 mm) 特徵阻抗 (50 ohm)

Design

Relative Permittivity How about microstrip line ?

Relative Permittivity

Filter Why do we need a filter?

Filter Types

Maximally flat Equal-ripple Linear phase

Filter Types Lumped Distributed

Coupled-Line Filter Each section is 0.25 lambda long.

Coupled-Line Filter It is very close to the practical value 42.4 !! We can use this formula to calculate our effective relative permittivity.

Amplifier

R1: bias C1: input match C2: output match C3: 900MHz short C4: RF decoupling

Layout of Amplifier

Mixer Mixer = Multiplier !? Active Nonlinear

Diode Mixer

FET Mixer

Layout of Mixer

The End *^.<*