AN3011: Deploying M/A-COM VCOs - Buffering, Mounting and Power Supplies

Voltage Controlled Oscillators (VCOs) are essential building blocks for signal generation where fast tuning is required. M/A-COM's line of Aerospace and Defence VCOs deliver excellent tuning linearity and low phase noise: critical parameters when designing Phase Locked Loops (PLL.) To obtain the best performance from M/A-COM VCOs, it is important to use best practice Radio Frequency (RF) design techniques. This application note discusses three important aspects of designing with M/A-COM VCOs: - Output loading: Proper termination of VCO RF outputs to maximise performance. - Mounting: Outline drawings for M/A-COM T08 and SMT-T08 VCOs. Recommended pad layout for SMT-T08 devices. - Power supplies: Minimising power supply noise. To achieve the best performance from M/A-COM VCOs, it is critical that good design practices are used in the layout of the RF circuit. The VCO RF output track, on the circuit, should be designed as a 50 ohm impedance. Line width should be calculated in accordance with the circuit medium dielectric constant and thickness.