Undergrad thesis project: Diseño, construcción y caracterización de un oscilador controlado por voltaje (VCO) para frecuencias de microondas las bandas ISM HECTOR MAURICIO PORRAS WILCHES September

GENERAL OBJECTIVE Design, build and characterize two oscillators controlled by voltage (VCO), in the ISM band. They will cover the frequencies at least from 857 to 928 MHz and 2.26 to GHz

SPECIFIC OBJECTIVES Build two prototypes of each design. Characterize and model the transistor that is used for the construction of the oscillators. Study the different options for the resonant load and choose the most appropriate. Study the different options for tuning the oscillator and choose the most appropriate.

1. DEFINITION An electronic oscillator is a electronic device that converts DC power in AC power A VCO is an oscillator whose central frequency is controlled by a voltage. [1]

2. SPECIFICATIONS Output power Frequency – Accuracy – Thermal changes – Pushing – Pulling – Phase Noise [3] B andwidth Modulation sensitivity Tuning speed [2]

2.1 AN EXAMPLE [7]

3. OSCILLATOR THEORY Feedback oscillator One-Port negative resistance oscillators Two-Port negative resistance oscillators [4]

4. RESONATORS Review series RLC and parallel RLC concepts – Zin – Unloaded Q – Loaded Q – BW

4. RESONATORS Types: – Lumped LC elements – Transmission line Short-circuited lines Open-circuited lines – SAW – Rectangular and circular waveguide cavities [5 y 6]

4. ACTIVE DEVICES BJT MOSFET JFETS MESFETS DIODOS

5. TUNNING TECHNIQUES Electronic – Varactor Mechanical – Screws

6. TOPOLOGIES Colpitts Hartley Clapp

6. REFERENCES 1. U. L. Rohde, “RF/Microwave circuit design for Wíreles applications”, 1st ed, Ed John Wiley & Sons, Inc, New York, 2000, pp M. Golio, “The RF and microwave handbook”, 1st ed, Ed CRC Press, Boca Raton, 2001, pp Jhon Silver. PhaseNoise.pdf. Disponible en 4. G. Gonzalez, “Microwave transistors amplifiers analysis and design”, Ed Prentice Hall, New Jersey, 1984, pp D. M Pozar, “Microwave Engineering”, 2nd ed, Ed. John Wiley & Sons, Inc, New York, 1998, pp R. W. Rhea, “Oscillator design and computer simulation”, 2nd ed, Ed Noble Publishing Corporation, Atlanta, 1995, pp Crystek Corporation. CVCO55CW Data Sheet. CVCO55CW pdf