Technical Aspects of Phase Lock Oscillator

A Phase Lock Oscillator is a high accuracy frequency signal source that gets its stability by being phase locked to a harmonic of a precision lower frequency reference.

The lower frequency reference has to be very accurate and very stable, with accuracy measured in ppm (parts per million) and stability measured in short term temperature variations typically over a day and aging over 1 to 10 years.

References range from low to extremely high cost depending on the end requirement. In its simplest form a simple Crystal Oscillator (XO) can about 1000ppm accuracy. However the frequency changes with Temperature giving birth to the TCXO (Temperature Compensated Crystal Oscillator) with accuracies 1-10ppm. A better stability is achieved in an OCXO (Oven Compensated Crystal Oscillator) where the crystal oscillator is mounted inside an oven held in narrow temperatures around 90C giving 0.1-1ppm accuracy. In the quest for even higher stability reference the GPS Signals form satellites are used and expensive Cesium and Rubidium Oscillators are used, Raditek provides all of the above references.

We can offer Phase Locked Oscillators from 1 to 110 GHz by using DRO, shigh performance FET oscillators, amplifiers, and Frequency Multipliers to produce desired power output and frequency.

The PLO needs will determine the use of variety of the apposite basic oscillator. Such fundamental oscillators function over the frequency ranges as given below:

1. PLXO- Crystal Oscillators 10 to 1400 MHz

• Very stable

• The best accessible phase noise

• Sensible cost

2. PLCRO- Coaxial Resonator Oscillators 0.5 to 3 GHz

• Extremely stable

• Best phase note

• Moderate cost

3. PLDRO- Dielectric Resonator Oscillators 7 to 42GHz and with Multipliers to 110 GHz

• Extremely stable

• Best phase note

• Affordable cost

References such as XO, TCXO and OCXO can be mounted inside the High Frequency Oscillator (IR). The more expensive ones are typically External (ER) and the reference shared over many.