采样率计算器

使用此采样率计算器快速获得准确的计算结果。

S11 (Return Loss at Port 1)

S21 (Forward Gain/Insertion Loss)

S12 (Reverse Isolation)

S22 (Return Loss at Port 2)

S21 Linear Magnitude

0.9441

S11 Linear Magnitude0.1778

S12 Linear Magnitude0.03162

S22 Linear Magnitude0.1000

VSWR at Port 11.43

Insertion Loss0.50 dB

S21 Linear Magnitude vs S11 (Return Loss at Port 1)

公式

Scattering parameters describe how RF energy propagates through a network.

S11: Input return loss (reflection at port 1)

S21: Forward transmission (gain or insertion loss)

S12: Reverse transmission (isolation)

S22: Output return loss (reflection at port 2)

Linear = 10^(dB/20) (for voltage/amplitude)

dB = 20 x log10(Linear)

For passive devices, S21 is negative (loss). For amplifiers, S21 is positive (gain).

A filter with S11=-15 dB, S21=-0.5 dB, S12=-30 dB, S22=-20 dB.

01S11 linear: 10^(-15/20) = 0.1778
02S21 linear: 10^(-0.5/20) = 0.9441
03S12 linear: 10^(-30/20) = 0.03162
04VSWR at port 1: (1+0.1778)/(1-0.1778) = 1.43
05Insertion loss: 0.5 dB

What does negative S21 mean?

For passive devices, S21 is negative (in dB) indicating insertion loss. For amplifiers, S21 is positive indicating gain.

What is good S11 for an amplifier?

S11 below -10 dB (VSWR < 2:1) is acceptable. Below -15 dB is good. Below -20 dB is excellent.

How are S-parameters measured?

Using a vector network analyzer (VNA) with calibrated test ports and known reference impedance (usually 50 ohms).

学习