VCO Tuning Constant and Tuning Methods Explained

This page explains the VCO tuning constant (K_VCO) and different VCO tuning methods. It also includes links to pages covering VCO basics and VCO types.

A VCO (Voltage-Controlled Oscillator) is an oscillator whose frequency can be varied by applying a voltage or current.

VCO Tuning Constant (K_VCO)

The VCO tuning constant, often denoted as K_VCO, specifies how much the VCO’s frequency changes per unit change in voltage or current. It is typically measured in Hz/Volt or Hz/Ampere. This constant is also known as the VCO gain.

The figure illustrates the VCO tuning constant.

For example, if a VCO’s tuning range is 2.4 GHz to 2.483 GHz (as per the Bluetooth standard) and the tuning voltage range is 2.7 Volts, then the tuning constant can be calculated as follows:

$K\_{VCO} = \frac{(2.483 - 2.4) \times 10^9}{2.7} \approx 30.7 \text{ MHz/Volt}$

It’s worth noting that the term “tuning constant” can be a bit misleading. The value becomes larger as the tuning range increases.

VCO Types and Tuning Methods