1. What is Output Transfer Admittance (Y21)?

The Y21 Parameter, also known as forward transfer admittance, is a two-port network parameter that represents the ratio of current at port 2 to the voltage at port 1 when port 2 is short-circuited. It is used in network analysis to characterize the forward transmission properties of electrical circuits.

2. How Does the Calculator Work?

The calculator uses the Y21 parameter formula:

Where:

• \( Y21 \) — Output Transfer Admittance (Siemens)
• \( I2 \) — Current in Port 2 (Ampere)
• \( V1 \) — Voltage Port 1 (Volt)

Explanation: The Y21 parameter quantifies how much current flows through port 2 when a specific voltage is applied to port 1, with port 2 short-circuited.

3. Importance of Y21 Parameter

Details: The Y21 parameter is crucial for analyzing and designing two-port networks, particularly in RF circuits, amplifiers, and filter design. It helps in understanding the forward gain and transmission characteristics of electronic systems.

4. Using the Calculator

Tips: Enter the current in port 2 in Amperes and voltage at port 1 in Volts. Both values must be positive and non-zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What are the units of Y21 parameter?
A: The Y21 parameter is measured in Siemens (S), which is the SI unit of electrical admittance.

Q2: When is port 2 considered short-circuited?
A: In Y-parameter calculations, port 2 is short-circuited when measuring Y21, meaning the voltage at port 2 is maintained at zero volts.

Q3: How does Y21 relate to other Y-parameters?
A: Y21 is one of four Y-parameters (Y11, Y12, Y21, Y22) that completely describe a two-port network's admittance characteristics.

Q4: What does a high Y21 value indicate?
A: A high Y21 value indicates strong forward transmission, meaning a small voltage at port 1 produces a large current at port 2.

Q5: Can Y21 be negative?
A: Yes, Y21 can be negative in certain circuit configurations, indicating phase inversion between input and output.