Introduction

Modern set-top TV DBS tuner systems require more channel coverage, while maintaining competitive prices. This situation creates tough design goals: to improve performance and simplify design.

Balanced VCO configuration could be a competitive circuit solution, since it provides the widest tuning range with practical circuitry and layout. However, tuning margins would be further improved by optimizing the varactor manufacturing process. Skyworks has developed such a process to satisfy the most ambitious wideband design goals.

In this publication, we will address the design of the balancedtype voltage control oscillator (VCO) based on the newly developed varactor SMV1265-011 with the unique set of capacitance tuning ratios and Q-quality.