Various schematics for colpitts oscillator with fixed ultra-high frequency using either LC tank circuits or one port surface acoustic wave resonator are presented. Four circuits used to achieve 433.9 MHz oscillating frequency, Two of them using NPN Bipolar junction transistor, while the others using operational amplifier with high speed, gain and accuracy. A comparison between using passive elements as a source of resonance frequency and using SAW resonator is introduced. Another comparison between using an equivalent lumped circuit instead of SAWR package in oscillator design is also introduced. Two different software tools are used to achieve the required simulation. Proteus and ADS tools are used in simulation with AC, S-parameters and hybrid simulation. This paper is considered a direct application for SAW resonators in wide bandwidth ASK Transmitter / Receiver. |
